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SOLID WASTE MANAGEMENT IN THE FABRICATED
RUBBER PRODUCTS INDUSTRY, 1968
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or
SOLID WASTE MANAGEMENT IN THE FABRICATED
RUBBER PRODUCTS INDUSTRY, 1968
Part I of this publication (S\V-22c) was written
for the Federal solid waste management program by
ROBERTS. PETTIGREWand FRANKH. RONINGER
Uniroyal Chemical, a division of Uniroyal, Inc.
under Contract No. PH 86-68-208
Environmental Protection Agency
Region V, Library
230 South Dc&rborn Street
ChicagOj Illinois 60604
U.S. ENVIRONMENTAL PROTECTION AGENCY
1971
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This report on solid wastes generated by the operations of the fabricated rubber
products industry was prepared by Uniroyal Chemical, a division of Uniroyal, Inc.,
pursuant to contract PH 86-68-208 with the Federal solid waste management program
(now part of the U.S. Environmental Protection Agency). The statements, findings,
conclusions, recommendations, and data in this report are not necessarily those of the
Agency, nor does mention of commercial products imply endorsement by the U.S.
Government.
The principal investigator was Robert J. Pettigrew with the support of the Commercial
Development and Research and Development staffs of Uniroyal Chemical and by the
Economic Analysis and Long Range Planning staff of Uniroyal, Inc.
Valuable suggestions and review advice were provided by Rodney L. Cummins and
Clarence A. demons of the Federal solid waste management program.
in
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PART I: CONTENTS
Page
SUMMARY 1
INTRODUCTION 4
ACKNOWLEDGEMENTS 5
FABRICATED RUBBER PRODUCTS INDUSTRY
History 7
Future Trends 8
DIVISIONS OF THE INDUSTRY
Tires and Tire Products 8
Canvas and Waterproof Footwear 13
Belts 17
Hose 17
Sponge and Foam Rubber Products 23
Mechanical Goods 26
Wire and Cable 26
COST OF SOLID WASTE DISPOSAL 29
RECOMMENDATIONS 30
APPENDIX
A - Methods and forms 30
B - Glossary of terms 31
INDEX
TABLES
Table 1-1
FIGURES
Figure 1-1
Figure 1-2
Figure 1-3
Figure 1-4
Figure 1-5
Figure 1-6
Figure 1-7
Figure 1-8
Figure 1-9
Figure I-10
Figure 1-11
Figure 1-12
Figure 1-13
Figure 1-14
Figure 1-15
Summary of industry waste, 1968
Concentration of the industry 2
New rubber consumption, total 9
New rubber consumption, % by industry groups 10
Tires, manufacturing process 14
Tires, number of units produced 15
Tires, product weight and solid waste 16
Footwear, manufacturing process 18
Footwear, production by number 19
Footwear, product weight and solid waste 20
Belting, manufacturing process 21
Belting, product weight and solid waste 22
Hose, manufacturing process 24
Hose, product weight and solid waste 25
Sponge and foam, product weight and solid waste 27
Mechanical goods, product weight and solid waste 28
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SOLID WASTE MANAGEMENT IN
THE FABRICATED RUBBER PRODUCTS INDUSTRY, 1968
The fabricated rubber products industry consists of those manufacturers who combine
elastomeric materials, fabrics, metal products, chemicals and mineral fillers purchased
from others and by suitable processing produce tens of thousands of different products
for the use of consumers and industry. The largest volumes of these products are
automotive tires, but they include canvas and rubber footwear, wire and cable covers,
hose and belting, foam and sponge, and the great variety of molded consumer and
industrial products grouped together as mechanical rubber goods. The common
characteristic of the industry is that its products are based on elastomers (rubber) to the
exclusion of similar products based on plastics. The industry does not include the
manufacture of synthetic elastomers nor the reclaiming of rubber as these are supplying
industries and not part of the fabricating industry.
In 1968 the fabricated rubber products industry produced 10.7 billion pounds of
products with a shipping value in excess of 7.5 billion dollars and employed about
250,000 people. There were some 1,500 companies operating at 2,000 locations but the
great majority were small specialty shops employing 10 people or less. If value of
shipments is used as a measure of production, manufacturing facilities in only 10 states
account for 75 percent of the output of products. These are the North Atlantic and East
North Central States plus Alabama, Texas and California. Figure 1-1 shows the
concentration of the fabricated rubber products industry in the important states as
percent of the total based on the value of shipments.
All of the 10.7 billion pounds of product will be used by consumers or industry and in
a fairly limited period will be worn-out and abandoned and enter into the general solid
waste mass of the country as will be discussed in Part II of this study, Waste Rubber and
Its Reuse, 1968.
This part of the study is concerned only with the solid waste problem which
(originates from the fabrication of rubber products and which) must be disposed of at the
manufacturing site. It is not concerned with ultimate disposal by the consumer of the
product or the product package.
In the manufacture of the 10.7 billion pounds of salable rubber products in 1968, it is
estimated that 1,058 million pounds of solid wastes originated from the fabricating
facilities and had to be disposed of at those locations. These solid wastes had no present
value and represented a disposal cost of about $9.5 million for collection, haulage and
dumping. This sum does not include the cost to the fabricator or processing these
semi-finished goods, but this internal cost is a constant stimulus to the producer to keep
wastes to the lowest level possible.
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The kinds and relative quantities of this manufacturer's solid waste will vary according
to the product or products made at a particular location. The complexity of the industry
has necessitated grouping the products made into six general categories and the types of
waste into five categories. Table 1-1 gives the estimated breakdown of fabricator's solid
wastes for the entire industry in 1968. Details for each of the product categories are given
later in the report as the quantity per million pounds of product as a guide to evaluation
of the solid waste problem for any specific location knowing the product mix at that
location.
In Table 1-1, and subsequent tables in this volume, the solid waste categories include
materials as follows. Paper, cardboard and wood includes all such inputs to the
fabrication plant as raw material bags and wrappers, carton, non-returnable wood boxes,
pallets, and shipping dunnage, machinery crates, production cards and stationery waste,
and production supplies. It does not include out-bound cartons, wrappings or other
packaging. Rubber compound includes in-process wastes consisting of trimmings, molding
wastes, damaged stocks, quality control rejects or other combinations of rubber, pigments
and chemicals which cannot be reprocessed in any way in the plant or sold to others at
some value. Textiles refer to woven, knitted, nonwoven, or cord textile products, usually
cotton or synthetic, which are used in fabricated rubber products and may be trimmings,
short ends, damaged goods or quality rejects from any stage of processing and are of such
a nature that they cannot be reprocessed in some way or sold to others for value. Metals
are both ferrous and non-ferrous wires, fittings or other attachments from damaged or
rejected products which cannot be recovered or sold for value and the largest part would
be ferrous beadwire from pneumatic tires or ferrous inserts from moldings. The other
category includes plastic wrapper film or worn-out separators, plastic and glass bottles,
metal cans or drums, and miscellaneous unclassified floor sweepings and other earthy
materials.
The tire and tire products segment of the industry accounts for about three-quarters of
the total weight of finished products but generates only about 40 percent of the total
solid waste. Because of the large volume of a single type of product, tires are generally
made by semi-automated procedures in modern or modernized factories. This permits the
use of bulk raw materials reducing the amount of input paper bags to be disposed of. It
permits standardized assembly procedures and better waste cost control and provides the
possibility of utilizing process waste in less critical products such as flaps and other tire
accessories. An important part of the rubber compound waste is cure-bags which are
relatively short-lived accessories to the tire curing operation and which when discarded
cannot always be sent to reclaimers.
Table 1-1
SOLID WASTE GENERATED BY THE FABRICATED
RUBBER PRODUCTS INDUSTRY: 1968
(Millions of pounds)
Type of Waste
Tires
and
Tire
Products
Paper, cardboard, and wood 100.5
Rubber compound 89.3
Textile materials 44.2
Metals 72.7
Other Materials 105.2
Type of Rubber Product
Foot- Belts Hose
wear
8.5 6.8 11.7
45.0 10.2 19.2
33.0 6.3 6.3
00.5 0.6 3.6
175 7.6 17.2
Foam
and
Sponge
Mech.
Goods
Total
9.6
54.0
0.1
—
16.2
65.5
140.7
42.8
21.3
102.0
202.6
358.4
132.7
98.7
265.7
Total Wastes
411.9 104.5 31.5 58.0 79.9 372.3 1,058.1
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For the footwear segment the paper input is small because much of the raw material
enters in a pre-processed condition to avoid soil. Because of the domination of hand work
on a great variety of small units, the wastage in rubber compound and textile material
trimmings is too high to use up entirely in lower quality components such as inner soles
and counter stocks. There is a limited market for these wastes to others, but the net
disposable waste is high.
For the belting, hose, and mechanical goods segments, which are usually combined in a
single plant, the big waste item is rubber compound, usually in the cured state so it
cannot be recycled. This segment is made up of a very large number of items largely
hand-built to rigid specifications. As a result there is a sizable amount of spoilage and
quality rejects which cannot be safely sold as off-grade products but must be scrapped
and disposed of as solid waste.
Most foam and sponge product raw materials are received as bulk water suspensions
and so the input paper is relatively small. The foam process in itself produces wastage of
rubber compound as trimmings and this makes up a large part of the solid waste. Many
attempts have been made to reconstitute this foam scrap into useful products but they
have met with little success as they lack the special properties of new foam. The waste is
not at all attractive to rubber reclaimers because of its bulkiness.
The problem of solid wastes is no novelty to the fabricated rubber products industry
forced upon them by the great number of units of an endless variety that they must
produce to rigid specification by largely hand assembly methods. Rubber industry
management is well aware of the internal cost of producing solid waste. This cost is
reflected in high reject rates, wasted raw material, and most of all, wasted labor, a high
price commodity. Short of further automation and other capital investment, there is little
likelihood that production wastes can be reduced further in the near future.
Most top management is not aware of the actual cost of solid waste disposal which
includes in-plant collection and baling, and outside hauling and dump fees or investments.
In many cases only lower management levels are aware of the actual disposal costs.
Several plants have salvage operations which sell all the waste they can and hope that this
revenue will offset part or all of the solid waste disposal costs.
Certainly more careful segregation of waste by kind would make disposal more
effective and possibly reduce the total amount by allowing more rework. Powder spillage
and trim scrap could be kept out of general waste and returned to process. Reworking of
plastic separator sheets was reported by one major company, cutting that particular waste
item to one-sixth of what it was. Such investments for reprocessing can reduce the
disposal costs and amounts of solid waste to be disposed.
The segregation of solid waste will allow for the incineration of the non-rubber portion
which accounts for sixty-percent of the material now being disposed of in land fill sites.
Present techniques waste valuable land fill sites by discarding many non-contaminating
combustibles in them. Further, incinerator technology should be developed that will
enable industry or municipality to burn rubber products without polluting the
atmosphere and thus eliminate much of the need for land fill operations in or near our
crowded metropolitan areas. Incineration is a short term solution to the problem.
Ultimately reuse and recycle are the long term solutions to the total solid waste problem.
The Solid Waste Disposal Act (PI 89-272) enacted by the Congress of the United States
in October 1965, authorized the Department of Health, Education, and Welfare to
initiate a piogram of research and development in solid wastes management. The Act also
authorized assistance to states, local governments, and interstate agencies as well as to
4
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private agencies, groups, and individuals in solving solid waste disposal problems in order
to alleviate this serious national problem. In order to efficiently perform responsibilities
under this Act, it is necessary that accurate basic information be made available on the
kinds, quantities, distribution and potential economic disposal of the solid wastes
generated by specific industries.
This study was performed with the generous cooperation of the fabricated rubber
products industry in order to evaluate the solid waste problems in the operation of this
specific industry. It is intended as a guide for all concerned with solid waste utilization
and disposal and it is hoped that it will be of assistance to the industry itself in its
continuing efforts to control the problem.
The study was conducted during the period July 1, 1968 to July 1, 1969 and
specifically covers the situation for the calendar year 1968 with historical backgrounds
and best estimates of the future through 1973. The information was obtained through
personal interviews as described in Appendix A, Study Methods, of this report.
Since many of the terms used may be unfamiliar outside of the rubber industry, the
less obvious ones are defined in Appendix B, Glossary, of this report.
/ V
A study such as the present one which encompasses the whole of a large and
diversified industry would not have been possible without the generous cooperation of
many knowledgeable individuals in that industry. We wish to express our thanks for the
assistance of the personnel of the following companies, associations, and institutes.
Acme Hamilton Manufacturing Corp. Brunswick Rubber Co.
Trenton, New Jersey New Brunswick, N. J.
Acushnet Co. Burke Rubber Co.
New Bedford, Mass. San Jose, Cal.
Aldan Rubber Co. Burton Rubber Processing
Philadelphia, Pa. Burton, Ohio
Alliance Rubber Co. H. O. Canfield, Inc.
Alliance, Ohio Clifton Forge, Va.
Amerace Corp. Carlisle Tire & Rubber Division
Butler, New Jersey Carlisle, Pa.
Ames Rubber Corp. Carol Wire & Cable Corp.
Hamburg, New Jersey Pawtucket, R. I.
Armstrong Rubber Co. Cat's Paw Rubber Co.
West Haven, Conn. Baltimore, Md.
Ashland Rubber Products Corp. Centrex Corp.
Ashland, Ohio Findlay, Ohio
A. Baker Manufacturing Co., Inc. Chemical Rubber Products, Inc.
South Bend, Ind. Beacon, N. Y.
Barr Rubber Products Comar Products, Inc.
Sandusky, Ohio Butler, N. J.
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Bata Shoe Co.
Belcamp, Md.
Beebe Rubber Co.
Nashua, N. H.
Bishop Manufacturing Co.
Cedar Grove, N. J.
Boston Woven Hose & Rubber
Cambridge, Mass.
Cooper Tire & Rubber Co.
Findlay, Ohio
Davol Rubber Co.
Providence, R. I.
De Laval Separator Co.
Poughkeepsie, N. Y.
Dunlop Tire & Rubber Corp.
Buffalo, N. Y.
Electric Hose & Rubber Co.
Wilmington, Del.
Faultless Rubber Co.
Ashland, Ohio
Firestone Tire & Rubber Co.
Akron, Ohio
Garlock, Inc.
Palmyra, N. Y.
Gates Rubber Co.
Denver, Colo.
Globe Manufacturing
Fall River, Mass.
Goodall Rubber Co.
Trenton, N. J.
B. F. Goodrich Co.
Akron, Ohio
Goodyear Tire & Rubber Co.
Akron, Ohio
Graflo Rubber Co.
Radford, Va.
Griswold Rubber Co.
Moosup, Conn.
Hewitt-Robins Inc.
Buffalo, N. Y.
I T T Wire & Cable Division
Pawtucket, R. I.
Collette Manufacturing Co.
Amsterdam, N. Y.
Continental Rubber Works
Erie, Pa.
Converse Rubber Corp.
Maiden, Mass.
Cooke Color & Chemical Co.
Hackettstown, N. J.
Lord Manufacturing Co.
Erie, Pa.
Lovell Manufacturing Co.
Erie, Pa.
Manhattan Rubber
Passaic, N. J.
Mansfield Tire & Rubber Co.
Mansfield, Ohio
Master Processing Corp.
Lynwood, Cal.
Midwest Rubber Reclaiming
East St. Louis, 111.
Monarch Rubber Co.
Baltimore, Md.
National Hose Co.
Dover, N. J.
Nearpara Rubber Co.
Trenton, N. J.
Oliver Tire & Rubber Co.
Oakland, Cal.
Pawling Rubber
Pawling, N. Y.
Permacel
New Brunswick, N. J.
Perry Rubber Co.
Massillon, Ohio
H. K. Porter Co.
Pittsburgh, Pa.
Republic Rubber
Youngstown, Ohio
Rome Cable
Rome, New York
Schenuit Rubber Co.
Baltimore, Md.
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Kirkhill Rubber Co.
Brea, Cal.
A Larkin & Son
Chicago, 111.
Laurie Rubber Reclaiming
New Brunswick, N. J.
Los Angeles Standard Rubber
Los Angeles, Cal.
Uniroyal, Inc.
New York, N. Y.
U. S. Rubber Reclaiming
Vicksburg, Miss.
Victor Balata & Textile Belting Co.
Easton, Pa.
Vogt Manufacturing Co.
Rochester, N. Y.
Associations
The Asphalt Institute
College Park, Md.
The National Tire Dealers and Retreaders Association, Inc.
Washington, D.C.
A Schulman, Inc.
Chicago, 111.
Swan Rubber Co.
Bucyrus, Ohio
Taylor Bros. Co.
Cleveland, Ohio
Thompson Aircraft Tire
San Francisco, Cal.
W. J. Voit Rubber Co.
Santa Ana, Cal.
Vulcanized Rubber & Plastics Co.
Morrisville, Pa.
West American Rubber Co.
Orange, Cal.
Xylos Rubber Co.
Akron, Ohio
Rubber Manufacturers Association
New York, N. Y.
The Rubber Reclaimers Association, Inc.
New York, N. Y.
HISTORY OF THE FABRICATED RUBBER PRODUCTS INDUSTRY
The term "rubber" is one of those unfortunate English
language expressions which has taken on many imprecise
and only vaguely related meanings. It is said that when the
native material first appeared it was first used for "rubbing"
(erasing) and so gained its name. The word now refers to
the natural vegetable product in its various forms, to
synthetic materials of a similar nature, to compositions
based on such materials, to finished products generally, and
to specific kinds of finished products. Foreign languages
have different terms for these different things but we must
suffer the confusion of a single term.
Rubber was first brought to Europe by the early
explorers of the tropics where it had been used by the
natives since ancient times to make slippers, balls, bottles,
toys and dolls. Natural rubber is the product of a wide
variety of unrelated tropical trees, shrubs and vines,
occurring as a watery dispersion (latex) in a separate system
of channels and tubes. It apparently functions as a reserve
food supply and as a protective material for the growing
plant from which it is gathered by controlled cutting or
injury.
Until about 1920, the rubber of commerce was almost
entirely the variable product of primitive gathering from
wild plants in Equatorial Africa and South America. After
many years of development, in the 1920's uniformly high
quality natural rubber from carefully managed plantations
in the Far East came on the market in sufficient quantity to
quickly replace the inferior wild rubbers. Because of wildly
fluctuating pi ices and unceitam supply, the rubber and
chemical industries were stimulated to develop synthetic
substitutes In the 1930's the fust truly useful synthetic
rubbers became commercial on a limited scale. In 1942
under wartime stress, a crash program by the federal
government cooperating with private industry established
the first large scale general purpose synthetic rubber plants
to produce the famous GR-S. In the past 25 years, one new
synthetic rubber after another has become commercial each
with its own specific value to the fabricator.
Practical rubber technology was developed in a limited
way in the first half of the nineteenth century by such men
as Macintosh and Hancock in England and Goodyear in the
United States. At first the products were of limited
usefulness. Although they had the unique property of being
waterproof, the rainwear, which was the principal product,
was intolerably sticky in warm weather and too stiff to
wear in cold weather. Modest improvements were made by
vapor or liquid treatment of the rubber surface in various
processes.
In 1839 Charles Goodyear discovered that if rubber
products containing flowers of sulphur were exposed to
heat they developed acceptable properties. This was the
discovery that firmly established the fabricated rubber
products industry. Soon a multitude of small plants in New
England and elsewhere were producing footwear, boots,
rainwear, medical sundries, hard rubber and simple
mechanical items. The Civil War not only proved the value
of these new manufactures but made them familiar to
soldiers and civilians from all parts of the expanding
country.
By 1900 the bicycle craze, rubber tired carriage wheels
and the beginnings of the automotive industry opened up
the tire market on a large scale. World War I military needs
proved the value of truck and bus transportation of goods
and people and made the first important pneumatic tire
market. Rubber was now big business and could support
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and encourage industrial and university research in the raw
materials, chemical additives, processes, and equipment by
many skilled scientists who changed a trial-and-error
industry into a highly sophisticated technology. It was none
too soon for service conditions were changing rapidly.
Expected tire mileage was going up while tire loading and
average road speed was steadily increasing. Rubber
technology was under constant pressure to convert a
relatively fragile composition into engineered products
capable of performing reliably under extremely severe
conditions.
FUTURE OF THE FABRICATED RUBBER PRODUCTS INDUSTRY
The rubber products industry will enter the 1970's with
a half century of sophisticated technology, a wealth of new
rubbers, fibers, and other raw materials to utilize, and with
major new engineering and design improvements to apply.
The problem will be to maintain reasonable prices, service
life, reliability and increasing output in the face of
increasingly severe performance requirements without
aggravating the inevitable solid waste problem of discarded
rubber products.
Because of the variety and complexity of the products of
the fabricated rubber products industry, it is necessary to
evaluate the industry size and growth by the amount of
natural and synthetic rubber polymer which is consumed,
which is reliably reported. The annual per capita
consumption of rubber polymer in the United States has
increased from a negligible amount in 1900 to seven pounds
per capita in 1930 and to thirty pounds per capita in 1968.
In Figure 1-2 the total consumption of rubber polymer is
traced from 1958 to the present and projected to 1973.
Growth was mildly erratic over the past ten year period but
averaged 5.4 percent per year. The projections through
1973 are a consensus of the industry and show a growth
rate of about 4.3 percent per year. It is a realistic
assumption that the product mix of the industry has not
materially changed in the past ten years and will not change
in the immediate future, and that the relative waste output
has and will remain nearly the same for this mature cost
conscious industry. In order to quantify the solid waste
problem directly from the fabricated rubber products
industry, we have presented in the right hand margin a scale
of solid waste in billions of pounds from which the weight
in any given year can be estimated.
The anticipated growth changes for the different
segments of this industry are discussed in detail in the
following specific sections.
Consumption of new rubber by the industry is reported
in three parts; tires and tire products, and other products.
The categories are not very helpful in detail, but the data
does illustrate the very dominant position of tires and tire
products. Figure 1-3 presents this information from 1958 to
1969 and forecast through 1973 as a percent of total new
rubber consumption. Tire and tire products consistently use
62 to 66 percent of all new rubber. Wire and cable use a
small part of the total which has remained constant in
absolute terms but has declined from three to one percent
of the total. The catch-all "other products" uses about a
third of the rubber in a great variety of items. Obviously
the industry does not anticipate any major shift in product
mix.
In the following sections of the report, trends and special
conditions in various segments of the overall fabricated
rubber products industry are discussed in detail. In these
sections the solid waste generated by the operation of
typical plants is given in terms of ratio to output,
specifically the average weight of solid waste to be disposed
of per million pounds of product produced. This should not
only be of value to waste control authorities in evaluating
their problems, but it is hoped will be of value to industry
management in improving their own plant performance.
TIRES AND TIRE PRODUCTS
The tire and tire products industry consists of those
manufacturing facilities comprised in the following
Standard Industrial Classification (1967 Manual) categories.
30111/30112/30113-11,-13,-15,-17
All pneumatic tire casings including passenger, truck and
bus, aircraft, motorcycle and scooter, bicycle, off-
the-highway, farm implement, tractor, and industrial
types.
30113-33,-35,-41,-51
All solid and semi-pneumatic tires for industrial and
highway use, for wheeled toys, baby carriages, bogies,
and idler and support rollers.
30114
All inner tubes for pneumatic tires.
30115
All tread rubber for tire retreading slab stock for further
processing, flaps, repair materials, and associated
products.
This segment produces 70 percent of finished product
weight of the entire fabricated rubber products industry
and six major companies produce 83 percent of the tires at
42 locations. Ten other companies produce the remaining
17 percent at 15 locations. Usually inner tubes are
produced in plants separate from the tire casing plant and
some tread stock for retreading is produced in detached
small facilities. In general all other solid tires and auxiliary
materials are made in the larger plants which produce tire
casings. Passenger car tire sizes account for 65 percent by
weight and 80 percent by number of all tires manufactured
in the United States.
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DISTRIBUTION OF TIRE PRODUCING PLANTS IN
THE UNITED STATES AS OF YEAR-END 1968*
Company
Armstrong
Cooper
Firestone
Gates
General
Goodrich
Goodyear
Mansfield
Mohawk
Uniroyal
Location
DesMoines, la.
Hanford, Cal.
Natchez, Miss.
W. Haven, Conn.
Findlay, Ohio
Texarkana, Tex.
Akron, 0.
Albany, Ga.
Barberton, O.
Bloomington, 111.
Dayton, O.
Decatur, 111.
DesMoines, la.
Los Angeles, Cal.
Memphis, Tenn.
Pottstown, Pa.
Salinas, Cal.
Denver, Colo.
Nashville, Tenn.
Akron, 0.
Bryan,0.
Charlotte, N.C.
Mayfield, Ky.
Waco, Tex.
Akron, O.
Ft. Wayne, Ind.
Los Angeles, Cal.
Oaks, Pa.
Tuscaloosa, Ala.
Akron, O.
Conshohocken, Pa.
Cumberland, Md.
Danville, Va.
Freeport, 111.
Gadsden, Ala.
Jackson, Mich.
Los Angeles, Cal.
Topeka, Kans.
Tyler, Tex.
Union City, Tenn.
Mansfield, 0.
Tupelo, Miss.
Akron, 0.
Salem, W. Va.
W. Helena, Ark.
Chicopee Falls,
Mass.
Units/
Day
20,500
10,500
18,000
15,000
13,000
1 1 ,500
27,000
17,000
8,500
50
20,700
22,000
22,000
15,500
28,000
30,000
15,000
18,200
12,000
9,050
30
1 1 ,000
19,800
16,000
6,000
18,000
11,500
19,000
21,000
38,000
13,500
20,500
5,500
14,000
44,000
30,000
18,000
30,000
15,000
17,500
14,000
10,000
6,000
4,700
10,000
28,000
Detroit, Mich. 33,700
Eau Claire, Wis. 31,000
Los Angeles, Cal. 16,500
Opelika, Ala. 13,500
Carlisle Carlisle, Pa.
Corduroy Grand Rapids, Mich.
Denman Warren, 0.
58,800
Dunlop Buffalo, N.Y.
McCreary Indiana, Pa.
Schenuit Baltimore, Md.
*Rubber World Vol. 159 No. 4 page 31, Jan. 1969.
This study was intended to reliably sample the entire tire
and products industry by direct interview as may be judged
from the following table.
MAJOR PRODUCERS
Corp. Plants
Industry 6 42
This Study 5
MINOR PRODUCERS
Corp. Plants
Industry 10 15
This Study 6
% OF CAPACITY
Major Minor
Industry 85 15
This Study 65 10
Table I shows the capacity of all tire producing facilities
in the United States as of the end of 1968 and their
geographical distribution as publicly reported.
The amount of solid waste generated in the manufacture
of one million pounds of tires and tire products is shown
below. These are average values for 1968 but because of the
similarity of operation from plant to plant, they are
representative of most operations in this category. There is
little reason to believe that the situation was much different
in the past ten years and no major improvement is to be
-------
expected in the next few years because this wastage has>
been recognized as a serious manufacturing cost for many
years and is under constant attack. The total wastes amount
to about 5.5 percent of the total weight of product made.
One million pounds of tire industry product is equivalent to
40,000 passenger tire casings.
Type of solid waste
Paper, cardboard and wood
Rubber compound
Textile material
Metal
Other
Total Waste
Pounds of waste per million
pounds of product shipped
13,400
11,900
5,900
9,700
14,000
54,900
The paper, cardboard and wood input waste is largely
paper bags in which carbon black, mineral pigments, and
chemicals are received. These are of little value for reuse in
the paper industry because of severe contamination by the
powders they contained. At least in the larger facilities
carbon black is now received in dustless bulk shipments in
cars or large returnable containers so the raw material bags
for this item are eliminated. There is a sizable amount of
in-process paper and wood waste from separator paper,
temporary wrappings, and card and paper stock used to
identify and control in-process materials. All of this paper
and wood waste could be handled in suitable incinerators if
properly segregated. At present in most cases no attempt is
made at segregation, proper incinerators are not available,
and the solid waste is handled by general collection, baling
or semicompression, and hauling to dumps.
The rubber compound waste includes solids containing
appreciable amounts of rubber which makes them
unsuitable for combustion in any ordinarily satisfactory
incinerator. Not only is the rubber hydrocarbon content
such that it burns with an obnoxiously sooty flame, but the
gases contain a large concentration of acid and sulfurous
gases. The waste is made up of in-process trimmings and
molding waste, in-process spoiled stock, curing bags, quality
rejects and experimental and test products.
Some of the in-process waste is used up within the plant
itself or related operations as raw material in low quality
goods such as flaps and light service solid tires and rollers,
but this means of disposal is limited by the product mix.
Curing bags are a tire-like structure of rubber with some
fabric which is inserted in the tire when it is cured to exert
internal pressure. For passenger tires, these units weigh 12
pounds apiece and will serve to cure 250 to 300 tires before
they must be scrapped. It is estimated that 7 to 8 million
pounds of these bags are scrapped each year, but since they
can be handled by reclaimers with some difficulty only a
part of the curing bags appear in the solid waste figures
above.
Finished tire rejects for quality reasons average one
percent for passenger tires and less than one percent for
heavier duty tires. In addition, there is a fraction of one
percent of finished tires which are partially or completely
destroyed in testing in the laboratory, on tracks, or in road
tests. These cannot be sold as off-quality goods and they
are not readily disposed of for reclaiming as new tires are
much more difficult to process than are service-aged tires
which have undergone desirable physical changes. All of
these new unsalable tires are included in the waste numbers
above, broken down into their known components.
Textile fabric and tire cord scrap (ends, clippings,
defects) which have not been rubberized find a ready
market with scrap dealers. Even the uncured tire carcass
scrap (trimmings and spoilage) which is 60 percent rubber
compound and 40 percent textile material usually can be
sold to scrap dealers for resale to the mechanical rubber
goods industry. Most of the amount under textile materials
would be the textile content of finished goods which
cannot be sold.
The metal waste at present is largely the high carbon
steel wire from the tire bead. This consists of defective
material, in-process waste, trimmings and the wire
component from finished good rejects. There is some
wastage of metal inner tube valves but this material finds a
ready resale as scrap metal and does not appear in the above
figures. At one time scrap bead wire could be compressed,
baled and sold as scrap steel for use in the steel industry but
it was never too desirable because of its bulkiness and of
recent years has found no market at all because of changing
steel production technology.
Changing tire construction designs may lead to changes
in both the quantity and kind of waste from the industry in
the future. The changes probably will not have too much
effect through 1973 but may be quite important thereafter.
Most of the pneumatic tires made through 1968 were of the
conventional bias construction in which the carcass was
built of diagonal layers of tire cord made of conventional
cotton or man-made fibers. In 1969, large numbers of
belted bias tires were made in which the carcass is
reinforced with circumferential belts of cords of glass fiber,
synthetic fiber or even fine steel wire. It is estimated that
these tires will give 15 to 40 percent more service life but
they will weigh about 18 percent more than the
conventional bias tire. There is no reason to believe that the
net solid waste ratio will change materially and although
fewer units may be marketed the weight of product will
remain the same. The only change should be that there will
be glass fiber in the scrap which will make it less attractive
for resale and more difficult to handle in incinerators.
Another type of construction may be an important
market factor by 1973 or later. This is the radial tire in
which the cords lie in radial planes which is believed to give
better service. These tires are being built in limited
quantities at present and because of production difficulties
the rejection rates are reported to be three to five times
those for conventional constructions. Before this
construction becomes commercially feasible, this difficulty
must be overcome but there may be some net increase in
waste production. In Europe where these tires are already
very popular, many of them are made with steel wire in the
carcass or in the belt, in addition to the conventional wire
bead. If this becomes popular m the United States, it will
12
-------
make even more difficult the problem of selling scrap or
disposing of wastes.
In Figure 1-4 a schematic outline of the tire
manufacturing process is given to show the possible origin
of the various types of scrap which will end up as solid
waste if it cannot be reused internally or sold for some
value. Figures 1-5 and 1-6 show the historical growth of the
tire industry by the two major types along with industry
consensus as to future growth through 1973. Figure 1-5
presents this growth in terms of unit casings, Figure 1-6 in
terms of weight of product shipped and weight of solid
waste to be disposed of. At one time tire manufacture was
dominated by original equipment sales for new vehicles but
road mileage of the national fleet has built up so high that
tire demand is more nearly related to gasoline sales than to
new car production. Also it will be seen that non-passenger
tire markets are now growing more rapidly than passenger
tire markets. Highway and air transport of goods and
people is expanding, farms are using more mechanical
equipment which requires pneumatic tires, and
construction is moving over to massive pneumatic tired
equipment. Not only are the relative number of units
increasing, but the relative weight of non-passenger tires is
increasing still more rapidly. Passenger tires averaged 22
pounds in 1968, truck and bus tires averaged 75 pounds,
and some specialty tires for off-the-road service weigh
hundreds of pounds. No substitute for the pneumatic tire
would seem feasible in the immediate future. Even
air-effect vehicles are said to use up more rubber in their
skirts than they would on pneumatic wheels, and their wide
acceptance does not seem imminent.
Inner tubes are somewhat different from tire casings in
the waste problem generated. They contain very little
textile material or metal and are nearly straight rubber
compound. The waste is almost entirely paper input from
raw materials and in-process trimmings. Inner tube scrap
and rejects find a ready market with scrap dealers because
they are clean compound and made exclusively from butyl
or natural rubber which is very desirable to reclaimers.
Scrap valves find a ready market on the metal scrap market.
It was not possible to obtain waste data on inner tube
production alone so the information is included in that for
tires and tire products. Very few inner tubes are now used
in passenger tires and then only in special cases such as wire
wheel mountings. In 1968, at least 80 percent of truck, bus
and heavier tires were operated with inner tubes because of
the severe service. Heavy duty tubeless tires are made but
the current consensus in the industry is that they will not
be a major factor by 1973, if ever.
Tread rubber and repair materials generate little if any
waste as they are uncured materials and can usually be
reworked. It is estimated that some 20 million pounds of
raw material packaging paper must be disposed of and that
is included in the tire and tire products total. Tire flaps and
sundries generate practically no waste and in fact are a
primary means of using up in-process scrap from other tire
operations.
RUBBER FOOTWEAR
The rubber footwear industry can be conveniently
divided into two parts, following the S.I.C. categories.
30210-11,-13,-15 Canvas Footwear
All footwear made of canvas and rubber including high-
and low-cut leisure, sports, and professional. They have
textile fabric uppers with rubber soles, heels, and trim.
30210-21 ,-31 ,-41 ,-51 Waterproof Footwear
All protective footwear made largely of rubber,
combined with fabric, leather, metal, and other
materials. It includes boots and waders, laced boots,
buckled and zippered arctics and gaiters of both utility
and style grades, and light and heavy pull-on shoe covers.
This report excludes all consideration of the above types of
footwear which are made of plastic materials in place of
rubber, but which are sometimes made in the same plant.
Separate rubber soles and heels or cured rubber slabs from
which they may be cut are excluded here as they are
classified under mechanical goods as described later.
In 1968 the canvas and waterproof footwear industry
produced 500 million pounds of finished product, or 190
million pairs of canvas footwear and 30 million pairs of
waterproof footwear.
The coverage of this study's interviews was as follows:
MAJOR
Corp.
Industry
This Study
MINOR
Industry
This Study
Industry
This Study
Corp.
38
0
Plants
12
7
Plants
more than 40
0
Percent coverage of
industry, this report
40
The amount of solid waste generated is shown below. It
was not possible to make a distinction between that of the
canvas and of the waterproof type as they are made in the
same plants.
Type of solid waste
Paper, cardboard and wood
Rubber compound
Textile material
Metal
Other
Total Waste
Pounds of waste per million
pounds of product shipped
17,000
90,000
66,000
1,000
35,000
209,000
13
-------
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260
240
220
200
180
140
120
100
80
60
Total Tire Casings
Passenger Size Tires
40
20
Truck and Bus Tires
Other Tires
1958 1960
1962
1964 1966 1968 1970
1972 1974
Calendar Year
FIGURE I-5 NUMBER OF AUTOMOTIVE TIRES PRODUCED
15
-------
8.0
.40
7.0
All Tires
6.0
•O
.2
m
u
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3.0
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.20
V,
a
Passenger Tire Sizes
2.0
1.0
.10
Other Pneumatic Tires
(Tractor, Aircraft, Construction, etc.)
.05
_L
_L
1958 1960 1962 1964 1966
Calendar Year
1968
1970
1972
1974
FIGURE I-6 PRODUCT WEIGHT OF TIRES PRODUCED AND
SOLID WASTE GENERATED IN THEIR PRODUCTION
16
-------
The paper waste is comparable to that for tires but little
of the raw materials can be received in bulk because of the
danger of soiling the product with loose dust. Metal waste is
small because few small metal parts are now used, mostly of
the zipper type. The rubber compound and textile material
scrap is high because the industry produces small units by
hand—assembled in a multitude of sizes and styles. Both
before and after combining with rubber, a great variety of
small pieces must be cut from sheet goods leaving
unavoidable waste trimmings. In the compression molding
process now common an excess of rubber compound is
used which appears as molding waste. Sponge innersoles
contribute considerable scrap because of the odd shapes
and sizes to which they must be cut. The trend to injection
molding in place of compression molding for attaching soles
to uppers will reduce the molding waste as the rubber
compound quantity can be more accurately fixed.
Some of the rubber and textile waste is ground up and
used in hidden parts of footwear. The remainder has no
value on the market and must be discarded.
The waterproof footwear industry has declined sharply
and the canvas footwear industry has begun to decline
slightly because of the competition of imports. Because of
the hand work involved lower labor costs off-shore make
lower prices possible. The quality is said to be lower but
perfectly adequate for the American consumer who is more
style conscious than ten years ago and less concerned with
durability. Imports account for 10 to 15 percent of the
canvas footwear domestic market and 20 to 25 percent of
the waterproof market, or a total of about 72 million
pounds of imported product.
In Figure 1-7 is given a schematic outline of rubber
footwear manufacture with the sources of the various kinds
of waste. Most production rejects are repaired and sold as
seconds and thirds. Rejects that must be scrapped are
reported to be less than 0.1 percent of production including
those destroyed in testing. Figure 1-8 illustrates the history
and probable future of the domestic industry in millions of
pairs produced. Figure 1-9 does the same for product weight
and the estimated solid waste generated in operations.
BELTS
The belts and belting portion of the fabricated rubber
products industry is comprised in the S.I.C. classification
30691. This includes flat belting for conveying materials
and for power transmission, V-belts for automotive,
appliance and industrial power use, and a wide variety of
belts for toys, business machines, instruments and other
devices. They vary in size from complete belts weighing as
little as two ounces up to mining conveyor belts weighing
up to 12 pounds per linear foot. Belts are generally built of
heavy textile fabrics or cord combined with cured rubber
compounds but they may include metal wire or cables. This
study covered what is estimated to be 85 percent of the
production of the belting industry as follows:
MAJOR
Industry
This Survey
Corp.
7
6
Corp.
MINOR
Plants
14
9
Plants
Industry 47 47
This survey 3 3
The solid waste generated per million pounds of belt
produced is as follows:
Type of waste
Paper, cardboard and wood
Rubber compound
Textile material
Metal
Other
Total Waste
Pounds per million pounds
of Products
27,300
41,000
25,200
2,300
30,200
126,000
Raw materials are almost all received in paper bags or
cardboard containers. Rubber compound and textile waste
is higher than for tires because less standardization and
automation is possible, but is much less than for footwear
because design is simpler and there is less variety. This
waste is largely cured and uncured trimmings and very little
of it can be reused in the same plant. The metal scrap is
ends and damaged material from those types of belts which
use metal reinforcement. The other waste is spilled
pigments and earth materials which get mingled in general
floor sweepings.
Belts which have minor defects are repaired in the plant
and sold as first quality product. Flat belts are made in
semi-continuous lengths and major defects can be cut out
and the remainder sold as short lengths of first quality
material. Splicing of lengths is also possible as they are
usually spliced on the job in any case.
A block diagram for belt processing is given in Figure
1-10 and past and estimated future belt production by
weight of product and estimated weight of solid waste
generated is shown in Figure Ml. The belt industry is
showing a steady growth supported as it is by the steady
growth of the automotive and appliance industry and by
the strong trend toward bulk movement of minerals, grain,
chemicals, industrial products, and people.
HOSE
The rubber hose segment of the fabricated rubber
products industry is comprised in S.I.C. 30692 and is made
17
-------
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580 -
540 -
Total Production, Rubber Footwear
.1
500 -
460 -
o
o
cc
•5
$
0)
420 -
120
100
80
1960
1962
1964 1966
Calendar Year
1968
1970
1972
60
1974
FIGURE 1-9 RUBBER FOOTWEAR PRODUCTION BY WEIGHT
OF PRODUCT AND SOLID WASTE GENERATED
20
-------
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380
340 -
300
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260
&
I
S
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220
180
140
100
1958
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45
40
35 |
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i
30
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25
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20
15
1960 1962 1964 1966
Calendar Year
1968
1970
1972
1974
FIGURE 1-11 RUBBER BELT PRODUCTION BY WEIGHT
OF PRODUCT AND SOLID WEIGHT GENERATED
22
-------
up of all types of household, retail service, appliance,
industrial and marine hose and tubings which are made in
part of rubber, with the exception of small medical tubing.
The types range from very small laboratory and instrument
tubings to very large and massively reinforced hydraulic
mining and dredging hose. Some types are solid rubber
compound, some such as firehose are nearly all fabric with
a minimum of rubber, and some are composites heavily
armored or reinforced with metal wire. The metal couplings
are attached in the factory except for lighter hose and
tubings. The one thing in common is that they are intended
to convey liquids and gases and are at least semi-flexible.
This survey is estimated to have covered 65 percent of
the total production of rubber hose. There are a large
number of small specialty manufacturers who could not be
visited but their processes would be much the same as those
reported. The table below will show the coverage.
MAJOR
Industry
This study
Industry
This study
Corp.
10
Corp.
115
5
MINOR
Plants
20
8
Plants
more than 130
5
Most of the major producers make a wide variety of hose
types in a single plant and they were unable to provide data
by type. The average solid waste generated per million
pounds of hose produced is as follows:
Type of waste
Paper, cardboard and wood
Rubber compound
Textile material
Metal
Other
Total waste
Millions of pounds per
million pounds of product
33,300
54,700
18,300
10,200
49,300
165,800
The paper scrap is largely from raw material packages
but contains as well, non-returnable wire reel cores and
textile yarn cores. Most of the reinforcing jackets are
braided from textile yarns or wire and little or no woven or
knit fabric is used. Most of the hose plants are old and not
well adapted to automation, a large variety of sizes and
styles are made in most plants, and the hose is built to rigid
specifications. These factors all tend to make in-process
spoilage a serious contributor to rubber compound and
textile waste. Since the textile fabric is braided in place,
there is little trimming and cutting waste as there is in the
other parts of the rubber product industry. There is little
possibility of salvaging the steel wire or steel jacket material
but the non-ferrous materials in reject fittings are either
renovated and re-used as such or sold as high value
merchant scrap.
Because of rigid performance specifications and quality
control standards rejects are high. In the past it was
customary to cut rejects into "short ends" and sell them as
substandard lengths for non-specification applications.
Because of misuse of these products and severe
manufacturer's liability rulings, it is no longer possible to
dispose of most rejects in this fashion and they must be
spoiled and become solid waste. The finished product
rejects that must be scrapped run 8-12 percent of total
production and their weight is included in the tabulation
above.
Much hose is cured in a temporary lead sheath to permit
the use of internal pressure. This lead is stripped in the
process and re-used over and over until it is too
contaminated to work well. The contaminated lead is sold
at scrap metal prices for refining and re-use. Some lead
oxides and dross probably get into other waste and is
reported as such.
A schematic diagram of hose manufacture is given in
Figure 1-12 and the history and forecast shown in Figure
1-13. The industry is thriving, thanks to growth in
automotive and appliance demands—especially automotive
air conditioning. The growth in marine shipments of
petroleum and chemicals has required large amounts of
large hose for product transfer.
SPONGE AND FOAM RUBBER PRODUCTS
Sponge and foam rubber products are included in S.I.C.
category 30693. This includes all the foam products which
are made from rubber latex, which is a suspension of
natural or synthetic rubber in water, such as cushioning,
mattresses, pillows, and carpet underlays. The sponge
products which are also included are made of solid rubber
which has been expanded by chemical blowing agents and
includes various insulation items, flotation items, seals for
windows and doors, and carpet padding. The products are
essentially rubber compounds as they rarely contain textile
materials or metal inserts. Although the range of products is
wide, the operating procedures are very similar for all
plants. There are a large number of small specialty plants
which could not be covered in this survey. It is estimated
that something less than 25 percent of the total industry
production was included and the extent of the interviews is
as follows:
MAJOR
Corp.
Industry
This study
Plants
more than 125
3
MINOR
Corp.
Plants
Industry
This study
more than 150
4
23
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-------
460
420
380
1
•S 340
•5 300
§
I
| 260
0)
220
180
140
1958
1960
1962
1964
1966
1968
1970
Calendar Year
FIGURE 1-13 RUBBER HOSE PRODUCTION BY WEIGHT
AND SOLID WASTE GENERATED
1972
75
70
65
60
I
a
55 £
50
45
3
oc
1
Q.
S
o
40 |,
I
35
30
25
1974
25
-------
The solid waste generated per million pounds of product
are as follows:
Type of waste
Paper, cardboard and wood
Rubber compound
Textile material
Metal
Other
Total waste
Pounds of waste per
million pounds product
16,000
90,000
200
Negligible
27,000
133,200
Since a large part of the raw materials used are received
as either bulk liquids (latices) or bulk powders (mineral
fillers) the paper waste from raw material receiving is low.
The other category includes liquid spillage which promptly
dries to useless solid rubber. This is included in "other"
with floor sweepings and other incidental waste. The rubber
compound waste, which amounts to two-thirds of the total,
is imposed by the process and the variety of products made.
Foam is molded either in slabs for further division or in
complete units such as mattresses, pillows, or chair
cushions. In either case the open molds must be over-filled
and the excess trimmed away. The slab stock is used as
blanks from which a multitude of shapes and sizes are cut
on order. This custom sizing makes a large amount of
three-dimensional trimmings which do not find a ready
market. Because of the low density of foam and sponge,
this material is very bulky and expensive to store; if finely
ground it can be a serious fire hazard. The ground material
cannot be reworked successfully and finds only a limited
market as reprocessing scrap. Attempts have been made to
bond this foam scrap with more latex to make secondary
padding for furniture but it has not been commercially
feasible.
Figure 1-14 shows the fairly modest growth of sponge
and foam products through the years. Growth would have
been much greater except for the inroads of urethane foams
which have many of the same values but are not included in
the rubber products industry.
MECHANICAL GOODS
This segment of the fabricated rubber products industry
includes the following S.I.C. categories:
30695 Mechanical rubber goods
30696 Rubber heels and soles
30697 Drug and medical sundries
30698 Other rubber goods
It excludes those groups already described.
Mechanical rubber goods includes tens of thousands of
molded and extruded items used by industry and as
components of consumer hard goods. It includes such
things as seals, rolls, inflatable goods, battery cases, fuel
cells for aircraft, dock bumpers, and many others. Rubber
heels and soles includes these items and the slab stock from
which they may be cut for use by the shoe industry and the
shoe-repair services. It is not a part of the rubber footwear
industry. Drug and medical sundries are such things as hot
water bottles, douches, medical tubings, and prosthetics.
Other rubber goods is a large conglomerate of items which
defy classification such as coated fabrics, rubber thread,
balloons, and custom compounded rubber for others.
There are well over one thousand plants producing these
materials to some degree but most of them are small
specialists. It is estimated that 35 percent of the production
was surveyed for this report as shown below.
MAJOR
Industry
This survey
Industry
This survey
Corp.
13
10
Corp.
1,000
18
MINOR
Plants
40
15
Plants
more than 1,000
18
The solid waste generated by this segment of the
industry per million pounds of product is as follows:
Type of Waste
Paper, cardboard and wood
Rubber compound
Textile material
Metal
Other
Total waste
Pounds per million
pounds of product
43,700
93,800
28,500
14,200
68,000
248,200
It is impossible to give a representative process
description because of the great number of ways of making
this conglomerate of items. They usually involve short runs
of handbuilt items of considerable complexity. Most of the
items are basically rubber compound with fabric and metal
inserts and reinforcement. The ratio of waste is the highest
for any segment of the rubber products industry for the
above reasons and all categories of waste are high. Only in
the case of soles and heels can trimmings and rejects be
ground and reused in the operation and regrind is said to be
50 percent of the rubber compound waste. The large
number of small plants makes it especially difficult to
collect and classify the solid wastes generated other than by
casual methods.
Figure 1-15 illustrates the growth of the industry and of
the solid waste generated. The growth is not spectacular as
it will have only doubled in quantity in 15 years.
WIRE AND CABLE
The wire and cable industry, which is traditionally
considered part of the fabricated rubber products, is
26
-------
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O
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.1
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Q_
»*-
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•6
n
780
740
700
660
620
580
540
500
460
420
380
340
300
1958
100
90
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"5
80
70
60
0)
§
O
0)
^
+^
I
50
40
1960
1962
1964
1966
1968
1970
1972
1974
Calendar Year
FIGURE I 14 RUBBER SPONGE AND FOAM PRODUCTION
BY WEIGHT AND SOLID WASTE GENERATED
27
-------
2.1 r-
2.0
/ -J
.50
1.9
1.8
.45
I
§ 1.6
CD
1.6
-S 1.4
g
o
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.9
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.35
.30
$
TJ
"5
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CD
.25
I
1960 1962 1964 1966
Calendar Year
1968
1970
1972
1974
FIGURE 1-15 MECHANICAL RUBBER GOODS PRODUCED
BY WEIGHT AMD SOLID WASTES GENERATED
28
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described as S.I.C. 3357, Insulating of Nonferrous Wire. At
one time all such power, communication, and other
electrical service wires and cable were insulated and
jacketed with rubber or rubber-like materials by
conventional rubber processes. The rubber component was
never very large in value or volume compared to the
nonferrous metal used in the industry, but at one time it
made up a sizable part of the rubber consumed. In the
period covered by this report, the rubber usage is low,
varying from three percent to one percent of total rubber
consumption, because of its large replacement by plastics in
many kinds of wire. The industry does pose a rather
unusual disposal problem.
The industry was reluctant to give information for this
survey so that not more than 10 percent of the total
production is covered, but it is believed it is representative
of the whole industry. The coverage was as follows:
MAJOR
Industry
This survey
Industry
This survey
Corp.
7
2
Corp.
49
1
Plants
10
2
MINOR
Plants
over 65
1
Some .175 million pounds of rubber compounds are
mixed in these operations much as in tire plants and applied
to the wire and cable in various ways, but usually by simple
extrusion. The finished product is of high value and made
to exacting standards on a continuous basis. Rejects
develop locally in testing and these lengths are cut out.
Rejects are stripped of rubber compound, which is
discarded and the core rerun. If the core is damaged the
rubber compound is burned off and the nonferrous core
sold in the scrap metal market. The solid wastes generated
in 1968 are estimated below as pounds per million pounds
of compound.
Type of Waste
Paper, cardboard and wood
Rubber compound
Textile material
Other
Total waste
Pounds per million pounds
of rubber compound
11,000
20,000
1,000
2,800
34,800
These numbers refer only to the rubber compound used
and not to the total weight of the industry product. No
metal waste is given as this is a concern of the wire industry
proper. The paper waste is that from the rubber compound
raw materials. The rubber compound is that which is
stripped or burned off of rejects. The textile waste is the
small amount stripped or burned with the rubber
component.
Future consumption of rubber compound by the wire
and cable industry should remain where it was in 1968, or
decline slowly.
COSTS OF SOLID WASTE DISPOSAL
The unit disposal costs of the solid wastes generated by
the fabricated rubber products industry are not related to
the product being made or the type of waste as they are
invariably mingled. Table 1-4 lists in-plant and external
disposal costs for twenty-one different plant sites. None are
in the same metropolitan area. Specific cities were not
named as it would be easy to relate to the companies
surveyed. Costs marked with an asterisk are for companies
falling within the 219 standard metropolitan areas.
Generally speaking, the costs in metropolitan areas are
higher than in the more rural areas of the country with the
exception of a few companies who own their own land fill
site rather than rent one.
In-plant collection costs include all direct labor,
supervision, and overhead for collecting waste from
operator's receptacles and delivery to a common pickup
point.
Out-plant haulage covers the contractor's price for
carriage and dump fees. The contractor sometimes owned
the dump, but generally paid the private or municipal fee as
part of his price. This cost varies widely with local labor
costs, availability of dumps, and distance to available
dumps.
It was impossible to obtain any more detailed
information as plant accounting systems only provide total
weight of waste dumped, total in-plant costs charged to this
function, and periodic billings by outside contractors.
29
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COSTS OF COLLECTING AND DISPOSAL OF SOLID WASTES
AT INDIVIDUAL PLANT SITES
Plant Site
1
2
3
4
5
9
10
11
12
13
14
15
16
17
18
19
20
21
In-Plant Collection
Cost/Ton
$10
10
13
20
10
13
7
20
26
18
27
15
17
12
4
25
25
NA
NA
NA
NA
Carting & Dumping
Cost/Ton
$19
6
8
10
5
12
8
20
13
4
13
6
11
8
13
20
12
NA
NA
NA
NA
Total Cost/Ton
$29*
16*
21
30*
15*
25*
15
40
39*
22
40*
21
28*
20
17
45*
37*
13
12
10
3
RECOMMENDATIONS
The following refers specifically to the problem of
disposing of the solid wastes generated by the fabricated
rubber products industry. The general problem of
comprehensive consumer rubber waste disposal is discussed
in Part II.
A primary interest of the rubber industry is to reduce
the quantity of waste generated. When it is noted that the
direct process waste (rubber compound, fabric, metal)
amounts to from 3% for tires to 25% for mechanical goods
based on weight of finished products, this represents a large
cost in raw materials and labor already put into
semifinished goods from which there is no possibility of
return. In fact, it increases the cost to get rid of them.
Through this study no material has been considered waste if
it is sold for any value whatever and no manufacturer's
value is included in the cost of disposal. The costs of all
waste produced and the costs of its disposal are a charge
against the product which is successfully produced and
marketed. There is no better incentive for minimizing waste
than profit pressure.
Management is always aware of the importance of waste
disposal as a national problem, but after their best efforts
to reduce the volume of their own wastage they feel they
have neither time, talent, nor resources to devote to the
problem. They do not consider present solid waste disposal
means as acceptable, so they simply turn over their solid
wastes to a contractor at a price.
The greatest need is for an economical incineration
system which will perform within firm long-range and
reasonable anti-pollution standards. Only a limited number
of rubber products facilities would be large enough to
maintain their own incinerator, but in some locations
groups of these and related industries could maintain one.
For isolated manufacturers, cooperation with municipal
operations will be in order. The two important require -
ments are:
1. Early establishment of practical firm long-term
standards for performance of incinerators in respect
to pollution control.
2. Support and encouragement of research and design
development on proper incinerators especially for
operation on solid rubber wastes or a large proportion
of rubber. If such incinerators could be further
developed to produce process steam, they would be
even more attractive as rubber fabricators are large
users of low pressure steam and this might offer some
return on costs.
APPENDIX A: STUDY METHODS
The first step in conducting this survey was to organize a
plan and make a selection of available sources of
information with the assistance and advice of experienced
30
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research, development and sales personnel of UNIROYAL,
INC. and others. Preliminary discussions were conducted
with production people of a few UNIROYAL fabricating
plants.
The questionnaire included in this appendix was then
made up in draft guided by the stated scope of the contract
and the realistic situation found in the few operations
investigated on a preliminary basis. This draft was then
revised after consultation with the project officer and other
personnel of the Bureau of Solid Waste Management. The
final form included here was then submitted for official
approval for use.
While awaiting this approval, all of the available
economic information on the entire fabricated rubber
products industry was collected and the pertinent details
arranged for this report. This includes the sections on
rubber consumption, product made, and value of product.
This includes past history, the situation in 1968, and a
preliminary estimate of the near future. At the same time
trade lists of the industry were used to plan a proper
cross-section of the industry by size, location, and kind of
facility. This plan was made more exhaustive than it would
be possible to cover because it was anticipated that some
interviews would be refused for one reason or another.
When the questionnaire had been officially approved for
use, telephone calls were made to fabricating companies in
such a way as to concentrate travel plans with the greatest
economy. The initial telephone call in each case was made
to the chief officer in charge of production; usually the
vice-president for production or his equivalent in smaller
companies. There were some refusals for various reasons
and in some cases there was referral to some other person
who was delegated to handle the matter. In all, in cases
where an interview was scheduled, it was done with the
knowledge and approval of senior management.
When an interview was scheduled, a copy of the
questionnaire was sent to the person to be interviewed for
his review and so he could assemble the information
necessary.
In no case was the completed questionnaire accepted by
mail or by telephone questions. The data for every
production facility included was collected by personal
interview either at that location or at a central location
where data on several facilities was available. In most cases
company records or abstracts of these were freely made
available to the interviewer and the more generalized
information supplied. It was found in practice that the
questionnaire was too elaborate for all situations, as some
individual questions could not be answered by all individual
plants. Also, because of the variations in records from plant
to plant, it required some ingenuity to calculate them to a
common basis. It was interesting that some forms of
information were considered too confidential to disclose at
some facilities, but were supplied freely at other facilities.
When most of the planned interviewing was completed,
the plan was reviewed for completeness and some
additional interviews were arranged to make the survey as
balanced as possible by size, kind, and geographical location
of the plants surveyed.
When interviewing was well along, collating of the
information was started, and when interviewing was
finished, all the information was assembled as in the body
of this report and cross-checked with the industry
economic summary previously made. There was some need
to make follow up telephone calls to the people interviewed
to clear up questions that only arose after assembly of the
information.
It had been hoped to transfer the data gathered on
punch cards or some other data processing form so it could
be given to the Bureau of Solid Waste Management without
identification of the facility involved so that they could use
it for further studies without any breach of confidence.
Because of the variation in record keeping and the lack of
consensus as to what could be disclosed, it was found
impossible to design any useful data processing system for
further studies.
APPENDIX B: GLOSSARY
Aircraft tires
Specially engineered pneumatic tires for aircraft designed for
massive impact loading and minimum total weight.
Air-effect vehicles
Vehicles designed to travel over land or water on a cushion of air
rather than on rubber tire wheels
Automotive
Properly any self-propelled vehicle but usually restricted to
passenger cars, trucks, buses, and towed trailers.
Banbury
A high powered mixing machine of special design commonly
used for blending and mixing rubber compounds.
Bead
The inelastic flanges of a pneumatic tire which firmly seat on the
rim flange and securely retain the tire on the wheel when the tire
is inflated.
Bead Wire
A high strength carbon steel wire which is precisely coiled to
form the core of the bead.
Carcass
Applied to the rubber and fabric body of the tire exclusive of the
all-rubber tread and sidewalls
Casing
Restricted to an unmounted pneumatic tire, in contrast to tire
which is the general term for the periphery of any wheel.
Chemicals
In rubber compounding the principal chemicals are various sorts
of cure accelerators, antioxidants, antiozonants, and other
organic chemicals used to protect rubber against degradation by
service and environmental agents.
Cord
Tire cord is a specially engineered rope-like structure of high
strength made of nylon, rayon, polyester, glass or other fibers
Consumer and industrial products
Consumer products are those which are distributed directly to
the ultimate consumer such as footwear, medical supplies,
replacement tires, or replacement parts for appliances. Industrial
products are those sold to industry as operating supplies or as
parts for new composites such as belts, hose, seals, and original
equipment tires.
31
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Cores
Are the wood, metal, paper or other sorts of cores on which
cord, fabrics, wire and other raw materials are supplied to the
fabricated rubber products industry. They are usually returnable
and reusable, but if damaged in the rubber plant they are
disposed of with the other solid wastes at that location.
Counter Stock
The stiff board-like material made of rubber, textile, and paper
fiber and used as protection and stiffening of shoe toes, heels,
and uppers. Since it is concealed, much plant scrap is used in its
production.
Curing Bag
A tire-like structure of rubber compound and some fabric which
is inserted inside an uncured tire when it is placed in the curing
mold to provide pressure and internal heat. The curing bag is
expendable after several hundred uses.
Cured Stock
Any rubber compound, with or without fabric, which has been
subjected to heat and is no longer thermoplastic.
Damaged Stock
In-process material which has been made useless for its intended
purpose by accidental semi-curing, by color change, by errors in
preparation, by water or steam damage, or other processing
accidents. Usually such materials can be blended off in small
amounts with fresh material, but some cannot be utilized or sold
to others for some value and becomes solid waste.
Dunnage
Wood, cardboard, or paper which is used to secure raw materials
or equipment in rail cars or trucks. There is a strong trend to
returnable dunnage, but there is still much that must be disposed
of at the receiving point as solid waste.
Elastomer
An elastomer is a substance which is capable of being altered by
curing to a condition in which if stretched to a limited degree at
room temperature it will return to substantially its original
dimensions in a short time when released. All of the so-called
rubbers and a few other organic substances are elastomers.
Extrusion
A process by which a thermoplastic material is forced through a
forming die to produce continuous lengths of pipe, tubes, and a
variety of profiles. Extrusion is applied to uncured rubber, to
many plastics, to metals, and many other thermoplastic materials.
Fabric
Fabric for the purposes of this report means any sheet goods
made of natural or man-made textile fibers by weaving, knitting,
braiding, or non-woven processes. It includes fabrics laid in place
of tire cord.
Fabricator
For the purposes of this report a fabricator is any installation
which receives raw materials or semi-processed goods from others
and converts them into complex finished products for consumer
or industrial sale.
Farm Tires
Includes all off-the-road tires which are used in agriculture
ranging from those on garden tractors to those on massive
specialized ploughing and harvesting rigs The heavily lugged tires
used on standard size farm tractors account for the largest share
of the total weight. Farm tires seldom wear out in the usual
sense, but are destroyed by irreparable damage from stones or
roots or environmental degradation.
Fittings
Those ferrous, non-ferrous, or plastic parts which are purchased
from others and made an integral part of fabricated rubber
products. Examples would be brass hose couplings, inner tube
valves, metal or plastic zippers for footwear, shoe eyelets, and
buckles for arctics.
Flaps
A tape used to protect casings and inner tubes from abrasion of
damaged metal wheels.
Floor Sweepings
In this report floor sweepings are the miscellaneous collection
swept up by factory and office janitors and consists of spilled
raw materials, paper scrap, staples, nails, and earth materials from
outside. There is no way of characterizing it except to include it
in "other solid waste."
Foam
The cellular rubber product made from liquid rubber latex by
whipping air into it, as distinguished from sponge (see below).
Inner Soles
The structural padding in the bottom of all types of footwear. It
may be a cushion of sponge rubber or a rigid concealed sheet
stock.
Inner Tube
The inflatable torus ring which is the air container in heavy duty
tires and in some medium duty tires. They are nearly pure rubber
compounds and almost always made of butyl rubber because of
its resistance to air diffusion.
Inserts
A wide variety of metal or plastic shapes which are bonded to or
contained within the finished rubber article. The threaded
closure in the neck of a hot-water bottle is a good example.
Latex
A suspension of very small solid rubber particles in a water
solution Natural rubber exudes from the tree in this form and
most synthetic rubbers are produced in this form or easily
converted to a latex. Latex is used in the manufacture of foam,
dipped goods, carpet backings, and other coatings and adhesives.
They are distinguished from cements which are solvent solutions.
Mineral Fillers
Fine ground mineral powders which are added to rubber
compounds to improve properties, to increase density or decrease
cost. Common ones are clays, whiting, magnesia, zinc oxide,
asbestos, and lead compounds.
Molding
The process of forming rubber products with heat and pressure in
precision formed molds. Various forms of molding are
compression, transfer, injection, slush, rotational, and open
mold. Compression molding is the traditional process for rubber
products, but injection molding is becoming more common
because of greater efficiency. Plastics are molded by very similar
processes.
Molding Waste
The overflow from the molding process including that from the
air release channels built into the mold. Mold waste is always
cured so it cannot be conveniently re-mixed.
Natural Rubber
Rubber originating from natural sources, almost entirely the
cultivated rubber tree of Southeast Asia, Indonesia, Ceylon, West
Africa, and a few minor tropical sources. It is marketed as either
solid rubber or the concentrated latex.
Pallets
Wood, paper, or plastic supports for piles of bags, bales, or rolls
of raw material to facilitate semi-automatic handling. They may
be either disposable or returnable. One-trip pallets or damaged
returnable pallets become solid waste at the point of delivery.
Pigments
Are strictly speaking organic or inorganic powders used to color
rubber products They include many mineral products such as
titanium oxide or zinc oxide which make white products. The
terms pigment and mineral filler are often used interchangeably.
32
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Pneumatic Tires
Tires containing an enclosed air space and having an elastic and
resilient body, the combination giving a smooth jolt-free motion
to vehicle on rough road-beds.
Polymer
A high molecular weight material made up of similar repeated
units of simple structure. All rubbers are polymers but the term
includes most plastics and many biological materials.
Product Package
Most consumer items and many industrial products are marketed
in some type of package for protection, identification, or
customer appeal. The package may be a cardboard box, a paper
jacket, paper wrapping, or a multitude of other types. Sometimes
a group of boxed items are shipped together in an outer case.
This material becomes solid waste at the point of ultimate
consumption and its weight is omitted from any numbers in this
report as it is obviously not a waste generated by the fabrication
of rubber products.
Quality Control
This incorporates all physical, chemical, or service testing of raw
materials, in-process material, and finished product to insure that
products meet the desired or required test specification. It would
include all research and development products where this work is
associated with a producing facility. Much of the raw material
and in-process material could be returned to process, but much
would be subjected to curing for test purposes and this, together
with spoiled finished product, would be disposed of as solid
waste.
Reclaimed Rubber
The product of physical or chemical processes which convert
scrap rubber products from any source into material which has a
limited use as a raw material for the fabricated rubber products
industry and certain other industries. It will be discussed in detail
in Part II of this report; in Part I it is considered as only another
raw material.
Rejects
Finished product which is judged by test to not conform to
established quality standards. In some cases a reject can be
repaired (belting and hose), or sold commercially as second or
third quality (footwear), or reprocessed (heels and soles) In
many cases repair or sale as off-quality cannot be tolerated and
the item must be made unserviceable and disposed of as solid
waste (tires, inner tubes, hose).
Retreading
The process by which sound tire carcasses which have had the
tread worn beyond safe levels by normal operation are
rejuvenated by molding on a new tread equivalent in safety
performance to the original.
Rubber
An unfortunately vague word having many different common
and technical meanings. Originally meaning the crude natural
product. It now covers all the synthetic elastomers, compounds
of them, and fabricated products. It also refers to the "rubbery"
properties of things that may not be elastomers at all. Then
specifically it may refer to such things as waterproof footwear,
prophylactics, and many other items.
Semi-pneumatic
A tire of heavy construction having an air space within it usually
at atmospheric pressure. They provide much less cushioning than
pneumatic tires and are used on light weight equipment or
industrial units.
Separators
Sheets of plastic, paper, or treated fabric which are used to
temporarily separate prepared pieces of tacky uncured rubber
prior to assembly. The trend is to plastic film which can be
recovered after use and reprocessed in the fabricating plant as
many as six or eight times. Treated paper and fabric can be used
over several times, unless it has been cut, and then must be
discarded as solid waste.
Solid Tires
A solid mass of rubber built up on the rim of a metal wheel with
no substantial air space. Usually limited now to small heavily
loaded wheels and rollers such as aircraft tail wheels, industrial
tractors, and conveyor rolls and casters.
Sponge
Cellular rubber products made from softened solid rubber
products containing chemical agents which decompose to gases
during the curing process.
Tire Accessories
Products associated with tires and wheels exclusive of casings and
inner tubes. Includes retreading compound, flaps, repair patches,
and cement, and a variety of small specialty wheels and parts.
Tread
That part of the tire casing which comes in contact with the
road It contains no fabric and is specially designed for abrasion
resistance and maximum skid resistance under all driving
conditions. This part of a sound tire can be effectively replaced
by retreading.
Trimmings
Almost all fabricated rubber products are assembled from sheet
or strip rubber compound, fabric or metal by hand or
semi-automatic operations. This requires much hand or machine
trimming of excess material to make the final shapes required.
Much of these trimmings may be reprocessed but the remainder
is discarded as solid waste.
Wire and Cable
This includes all electrical conductive power, communication,
and electronic wires and cables. At one time all the insulation
and jacketing of the non-ferrous conductor was based on
elastomers but now much of the elastomer has been replaced by
plastics such as polyolefins and polyvinyl chloride which do not
require a curing stage as elastomers do. The remaining use of
elastomers is in applications where its abrasion resistance,
moisture resistance, and electrical properties are superior at lower
cost. The performance specifications in most of this industry are
very rigid.
Rubber Compound
Intimate mixtures of elastomers, oils, mineral fillers, pigments,
chemicals, sulfur, and other modifying materials. It usually refers
to uncured material.
Rubber MiU
An open mixer for making rubber compounds consisting of two
powered rolls operating in opposite or the same directions, at
various rotational ratios, and either smooth or grooved in various
ways.
33
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WASTE RUBBER AND ITS REUSE: 1968
Part II of this publication (SW-22cj was written
for the Federal solid waste management program by
WALTER J. MARKIEWICZ and MICHAEL J. GRANSKY
Uniroyal Chemical, a division of Uniroyal, Inc.
under Contract No. PH 86-68-208
U.S. ENVIRONMENTAL PROTECTION AGENCY
1971
-------
-------
This report on solid wastes of the Rubber Industry was prepared by Uniroyal
Chemical, a division of Uniroyal, Inc. pursuant to Contract No. PH 86-68-208,
with the Federal solid waste management program (now part of the U.S.
Environmental Protection Agency). The statements, findings, conclusions,
recommendations, and other data in this report are not necessarily those of
the Agency, nor does mention of commercial products imply endorsement
by the U.S. Government.
Valuable support was provided by the Commercial Development and the
Research and Development Staffs of Uniroyal Chemical and by the
Economic Analyses and Long Range Planning Staff of Uniroyal, Inc.
in
-------
e
A study such as the present one which encompasses the whole of a very large industry
could not have been successful without the generous cooperation of many individuals in
that industry. We wish to express our thanks for the assistance of the personnel of the
following companies:
Amerace Corp.
Butler, New Jersey
A. Baker Manufacturing Co., Inc.
South Bend, Indiana
Boston Woven Hose & Rubber Div.,
American Biltrite Rubber Co., Inc.
Cambridge, Massachusetts
B.F. Goodrich Co.
Akron, Ohio
Goodyear Tire & Rubber Co.
Akron, Ohio
A. Lakin & Son
Chicago, Illinois
Laurie Rubber Reclaiming Co.
New Brunswick, New Jersey
Midwest Rubber Reclaiming Co.
East St. Louis, Illinois
A. Schulman,Inc.
Chicago, Illinois
Swan Rubber Co.
Bucyrus, Ohio
Centrex Corp.
Findlay, Ohio
Firestone Tire & Rubber Co.
Akron, Ohio
Gates Rubber Co.
Denver, Colorado
Uniroyal, Inc.
New York, New York
U.S. Rubber Reclaiming Co., Inc.
Vicksburg, Mississippi
Associations
The Asphalt Institute
College Park, Maryland
The National Tire Dealers and Retreaders
Association, Inc.
Washington, D.C.
The Rubber Reclaimers Association, Inc.
New York, New York
-------
PART II: CONTENTS
Page
SUMMARY 35
INTRODUCTION 37
SECTION I-WASTE RUBBER: 1968
Distribution of Scrap Rubber Products 40
Collection of Consumer Rubber Product Waste 43
Present Reuse of Waste Rubber 43
SECTION II-THE RECLAIMED RUBBER INDUSTRY
History of the Reclaimed Rubber Industry 48
The Reclaimed Rubber Industry 49
Waste Rubber Input 51
Industry Solid Waste 52
The Reclaiming Processes 56
Trends in the Reclaim Industry 59
Processing Advantages and Cost Savings 61
Reclaim Exports/Imports 61
SECTION III-THE RETREAD INDUSTRY
History - 65
The Retread Industry 65
Processes 66
Trends in the Industry 67
SECTION IV-THE TIRE SPLITTING INDUSTRY
History of the Tire Splitting Industry 72
Tire Splitting Industry 72
Solid Waste and By-Products from Industry 72
SECTION V-MITIGATION
Solid Waste Rubber Management Program 76
Collection 76
Shipping and Storage 76
Potential Reuse with Reprocessing 77
SECTION VI-CONCLUSIONS AND RECOMMENDATIONS FOR FURTHER ACTION
APPENDIX I - GLOSSARY 82
APPENDIX II - BIBLIOGRAPHY 83
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INDEX
TABLES Page
H-l Distribution of Consumer Rubber Products Waste by States 42
H-2 Waste Rubber Used and Available: 1968 43
II-3 Tire and Other Waste Reuse 44
114 Reclaim Plant Locations 49
II-5 Reclaim Production as a Percent of Capacity 50
H-6 1968 Rubber Waste Usage by Reclaimers 51
II-7 Reclaim Industry Solid Waste: 1968 52
II-8 Reclaim Consumption by Product 60
II-9 Production of Retreaded Tires 65
11-10 Weight of Worn Tires Used in Retread Industry 66
II-l 1 Buffings Produced Annually 66
II-12 Total Waste from Retreading Industry: 1968 66
11-13 Tire Splitting Material Balance 72
II-14 Tire Splitting Industry Waste 73
II-15 Estimated Cost of Portable Rubber Waste Chopper 76
FIGURES
II-l Geographic Percent Distribution of Waste Rubber 41
H-2 Discarded Tire Destination 45
II-3 Reclaim Plant Locations 50
114 Digester or Wet Reclaim Process 53
II-5 Pan or Dry Reclaim Process 54
H-6 Rubber Crumb Process 55
II-7 Reclaiming Process Chart 57
II-8 Reclaim Consumption as a Percent of Total New Rubber 59
H-9 Reclaim Exports/Imports 62
II-10 Domestic Passenger Tire Shipments and Retreads 68
II-l 1 Domestic Truck Tire Shipments and Retreads 69
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This report outlines the waste rubber product disposal problem, the present areas of
waste reuse with future trends, and potential future areas of collection and reuse. The
base year was taken as 1968.
Section I presents (a) the geographic distribution of two categories of rubber waste, one
category being more easily collectable than the other; (b) the collection methods
presently used for waste now reused and (c) the wastes consumed by the three major
users.
Section II details one of the waste users, the Reclaim Rubber Industry, its history, the
wastes used and created, the processes used, and the industry trend.
Section III details the Retread Industry, the largest single user of rubber waste, its
history, wastes used and created, the process and industry trend.
Section IV outlines the smallest of the waste reusers, the Tire Splitting Industry.
Section V is an analysis of the various methods of waste collection and reuse which might
be used for mitigating the problems caused by rubber product waste.
Section VI presents some specific conclusions and recommendations for further action.
Section I
Of the 10.7 billion pounds of rubber products produced in 1968, after wear allowed for
in vehicle tires, approximately 10.3 billion pounds will ultimately become a waste
disposal problem.
Approximately 6 billion pounds will be various types of tires for automotive, truck and
farm vehicles. It is mainly this type which is presently used in any significant quantities
by the three major waste reusers, amounting to 1.95 billion pounds.
Approximately 11% of this collected waste* or 213 million pounds is subsequently
rejected for various reasons by these industries as waste for disposal.
The overall net waste for disposal is then estimated at 8.6 billion pounds consisting of 4.3
billion pounds of tires and 4.3 billion pounds of other rubber product waste.
Twenty million pounds of new waste are created during the reuse of the remaining 1.7
billion pounds of rubber waste.
35
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Section II
Over the past 10 years, the Reclaim Industry produced between 550 to 650 million
pounds per year of useable product primarily from rubber waste and rubber industry
scrap. The Reclaim Industry waste consists of 62 million pounds of unused waste and 13
million pounds of newly created waste.
During this 10 year period, reclaimed rubber as a percent of new rubber polymer has
decreased from 18% to 10% indicating a loss of market or usefulness to the rubber
industry. It is anticipated that the pound volume will continue to decrease in the near
future.
Section III
The largest users of rubber waste are the tire retreaders who accumulated 1.6 billion
pounds of road worn tires. Approximately 1.56 billion pounds were recycled back to
consumers with the addition of approximately 530 million pounds of new tire tread. The
remaining 0.04 billion pounds of worn tires were rejected as unsuitable for retreading.
The tread rubber added to the 1.56 billion pounds of tires is included in the 10.7 billion
pounds of new rubber products made in 1968. Newly created waste was 4 million
pounds. There has been a steady though small increase in the numbers of tires being
retreaded every year particularly the heavy service truck type tires and this increase is
expected to continue. Without this recycle of worn tires back into service, it is logical to
assume that more new tire production would be necessary to satisfy the market thereby
increasing the future tire waste from 6 billion pounds per year to well over 7 billion
pounds.
Section IV
The tire splitting industry uses rubber waste, mainly tires, to produce rubber washers,
gaskets, shims, automotive tail pipe hangers, and the familiar door mats. Of the 57 million
pounds consumed by the industry, 14 million pounds were converted into finished
products, 36 million pounds were sold to reclaimers as selvage, and 7 million pounds were
returned to waste. There was 3.6 million pounds of new waste created by this industry.
Without past history on volume of waste consumed, it is difficult to establish industry
trend, however, it is an industry expectation that volume will continue to increase.
Section V
It is suggested that the rubber waste program be divided into two categories, tire waste
and others. A collection system already exists for waste tires to serve the three major
users, collecting approximately 30% of those available. It may be possible to expand this
system as a nucleus for collection of the remaining 70%. The "other" category will be
extremely difficult to collect and sort into useable waste. Alternate collection systems
and storage sites are considered. Methods for facilitating disposal of rubber waste through
incineration or land-fill were considered including stationary and portable shredders; the
use of shredded waste in roads, crash barriers, as a mulch or road banks was also
considered as well as the longer range potential outlets as pyrolysis to either chemicals or
fuel gasses.
Section VI
Seven specific recommendations are presented for future study. The logistics of waste
collection oriented primarily to tire accumulation should be investigated. A study based
on the reverse logistics of new tire distribution is suggested. Facilities for shredding and
densifying waste followed by incineration or conversion to other useful products are
discussed. The use of waste rubber in asphalt roads will require specific studies and test
roads. It is also recommended that the Bureau of Solid Waste Management maintain
surveillance over legislation, industry standards, and technological changes to ensure that
the solid waste problem is not inadvertently aggravated.
36
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This report outlines the entire Waste Management problem concerned with discarded
consumer rubber products based on products manufactured in 1968 and waste products
also reused in 1968.
While the rubber products industry has been growing at a steady pace as described in Part
I of this report, the waste reuse or management in pounds in recent years has remained
virtually constant. The overall effect is a lower percent of waste reused. The three largest
(virtually 100%) users of waste rubber products show the following usage changes
between 1963 and 1968 respectively. Reclaimers produced 0.629 billion pounds vs. 0.576
billion pounds. Retreaders reused 1.43 vs. 1.56. No comparative data are available for
splitters which is small usage by comparison. The overall total was 2.06 billion pounds
reused in 1963 vs. 2.13 billion pounds in 1968.
Although minor favorable cost differentials may exist between reused rubber products
such as reclaim and retreaded tires, other disadvantages — real (potential by lower
quality) or imaginary (second class reused stigmatism) — have precluded any significant
growth in usage.
While waste rubber products are not unique with respect to other types of waste, they
have inherent in them many of the difficult disposal characteristics of the others. They
come in combination with other materials as fibers and metals; are made in various sizes
and shapes; are scattered over the length and breadth of the land; are not easily
degradable in land fill type operations where the large items such as automotive tires have
the added disadvantage of resisting compaction; and although readily combustible they
contribute substantially to air pollution problems when burned in ordinary, low quality
incinerators. To put this survey into perspective, Section I of this report details the
geographic location of the waste, subdividing the waste into two categories. The first is all
tires which constitutes approximately 59% of the total waste and which is more readily
collected and reused. The second category is the broad "Others" which covers a
multitude of rubber products, difficult to collect, sort, and reuse in any foreseeable
outlet. Section I also outlines the three major industries engaged in the reuse of waste
rubber products.
Section II covers one of the waste converters, the Reclaim industry, its history, the wastes
used and created, an outline of processes and equipment used, and the industry trends.
Sections III and IV similarly outline the other two major uses of rubber waste, the
Retreaders and Tire Splitters respectively.
Section V outlines some broad solutions to achieve more effective waste management
with specific conclusions and recommendations listed in Section VI.
A Glossary and a Bibliography, subdivided in various topic classifications, are included in
the two Appendices.
37
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DISTRIBUTION OF SCRAP RUBBER PRODUCTS
During 1968, 10.7 billion pounds of rubber products were
produced in the United States. On the assumption that
unless reused for another purpose after wearing out, the
rubber product will be discarded in the same locale as
purchased, the geographic waste distribution can then be
determined. Based on information on product sales by
country and metropolitan areas, TABLE II-l details the
distribution by states. The distribution is further subdivided
into two categories, Tire and Others. The assumption is that
the first category is more easily collected and lends itself
more readily to reuse while constituting 59% of the total
10.7 billion pounds of discarded rubber products. The basis
for these assumptions will be further developed in
subsequent portions of this report. The Tire category
includes passenger, truck and large tractor tires and the
Other category includes all the remaining rubber items such
as innertubes, garden hose, hot water bottles, mats,
windshield wiper blades.
Also included in TABLE II-l is the product distribution per
capita and per square mile of each state area. This is an
indication of each individual state's disposal problem
particularly by land-fill; from a high of 41,650 pounds per
square mile per year for New Jersey, neglecting the 677,970
pounds per square mile for Washington, D.C. to a low of 20
pounds per square mile per year for Alaska, where land is
undoubtedly less expensive than in New Jersey. It is
interesting to note the higher per capita usage of rubber
products in the predominantly rural areas of for example
Wyoming, 72.4 pounds per capita per year and Montana,
70.1. This is primarily due to the large number of farm
implements owned by residents in addition to the
automobile and usual home rubber products and to the low
density of population and consequent greater motor vehicle
use per capita to participate in the daily life of a typical
community.
These figures are not adjusted for the waste consumed by
the major converters. They do not include the retreaded
tires which are being recycled in the amount of 1.6 billion
pounds in 1968 compared to total new tires of 6.0 billion
pounds. While the 1.6 billion pounds are not disposed of in
1968, tires recapped in previous years will be, therefore the
overall net waste is considered to be the 6.0 billion pounds.
It can be assumed that the Retreaders are uniformly
distributed over the country. However, the next largest
consumer, the Reclaimers are not uniformly distributed,
with a high concentration in the Ohio and Northeastern
sections. Since waste converted by them is normally not
drawn from distant points, it therefore seems logical to
assume, since accurate data could not be developed, that
the waste disposal problem in these areas is reduced. A
listing of Reclaimers is noted in Section III.
The third largest consumer, the Parts Industry, although
small by comparison, is mainly located in the Chicago-St.
Louis areas.
Another method of analyzing the distribution data clearly
emphasizes the logistical problem in collecting the rubber
product waste. In Fig. II-l the United States is subdivided
into standard census geographic areas. The circles within
these areas represent groups of metropolitan districts with a
100 mile radius whose total rubber product usage is at least
1% of the nation's total, each one percent equivalent to 100
million pounds per year. Percentages shown within the
circles do not include usage in rural or small towns within
the circle, which is included in the total percentages for the
specific geographical area. It is noted that 51% of the waste
is included within the 20 circles with the remaining 49%
thinly spread over the remaining areas. The mid-Atlantic
axis (Boston-Wilmington) accounts for about 15% of the
total. The mid-West axis (Milwaukee-
Chicago-Detroit-Cleveland-Pittsburgh) accounts for about
9%. The remaining two-thirds of the waste however is
widely distributed over the remaining isolated metropolitan
circled areas or the rural-small town areas in between.
40
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41
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TABLE II-l
DISTRIBUTION OF CONSUMER RUBBER PRODUCT WASTE BY STATES
STATE
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Washington, D.C.
Total
Percent
TIRES* OTHER
(thousand pounds)
98,060 77,790
6,600 5,390
71,960 30,770
72,850 42,300
598,730 374,410
100,860 41,460
76,670 60,260
15,210 10,690
194,640 118,000
126,020 94,030
12,760 15,000
29,730 15,810
289,330 240,200
163,220 111,130
130,990 65,820
90,570 51,720
90,780 72,230
116,670 77,360
30,650 23,080
95,670 73,940
123,740 122,670
239,360 186,350
133,070 81,200
69,800 51,720
194,830 103,000
37,020 16,240
73,000 33,760
19,650 7,000
19,000 14,530
181,940 114,460
37,960 22,650
370,520 400,050
133,900 108,560
29,260 15,000
328,370 231,230
100,720 55,140
85,430 41,890
330,710 269,700
23,350 20,520
56,650 56,850
32,390 16,240
124,000 85,050
380,010 228,240
42,500 20,940
11,230 9,000
117,470 94,460
105,290 68,000
48,800 44,020
111,770 94,030
16,850 7,700
28,400 18,380
6,018,960 4,269,970
59% 41%
TOTAL
175,850
11,990
102,730
115,150
973,140
142,320
136,930
25,900
312,640
220,050
27,760
45,540
529,530
274,350
196,810
142,290
163,010
194,030
53,730
169,610
246,410
425,710
214,270
121,520
297,830
53,260
106,760
26,650
33,530
326,400
60,610
770,570
242,460
44,260
559,600
155,860
127,320
600,410
43,870
113,500
48,630
209,050
608,250
63,440
20,230
211,930
173,290
92,820
205,800
24,550
46,780
10,288,930
100%
AVERAGE
LBS/CAPITA
50.6
45.0
57.7
56.5
49.7
65.7
47.6
49.2
50.7
49.2
40.7
62.0
50.0
54.5
67.4
60.3
52.1
52.4
55.8
46.7
48.1
50.4
58.3
52.2
61.5
70.1
69.2
53.1
49.8
47.6
58.7
45.1
49.4
65.5
53.4
59.8
59.8
52.8
50.5
46.6
68.1
53.4
54.4
58.3
49.6
47.7
55.2
53.8
50.6
72.4
56.9
AVERAGE
LBS/M12
3,410
20
900
2,170
6,130
1,370
27,336
12,590
5,340
3,740
4,320
550
9,400
7,560
3,500
1,730
4,040
4,000
1,620
16,040
29,840
7,300
2,550
2,550
4,270
360
1,380
270
3,600
41,650
500
16,070
4,600
630
13,580
2,230
1,310
13,244
36,140
3,650
630
4,950
2,280
750
2,100
5,190
2,540
3,840
3,670
250
677,970
The weight of rubber "lost" through tire wear has been
deducted from these figures.
*Passenger, Truck and Large Tractor.
42
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COLLECTION OF CONSUMER RUBBER PRODUCT WASTE
Aside from automotive tires and innertubes, there is
apparently little other segregated collection of the nation's
worn rubber articles. Tires and innertubes are collected or
accumulated mainly by tire stores, gasoline stations, fleet
operators, and retreaders. When a tire is worn out, it is
usually changed or replaced by a new tire at one of these
commercial operations. Few tires are replaced by motorists
themselves. This practice normally results in tire
accumulations at convenient pick-up points. In areas where
tires are a disposal problem, however, it is a common
practice for the station attendant to put the worn tire back
into the trunk of the customer's auto and the tire ends up
unsegregated in the residential solid waste. When innertubes
are no longer required they are usually saved by the
motorist against the day when he may need it again for a
leaking tire, for a swimming tube, or for a use to be
determined. It invariably ends up later in residential waste.
Almost all other types of rubber waste (excluding rubber
waste from the rubber industry) from worn rubber
products are easily disposed of in mixed waste. For
example, discarded rubber gloves, boots, mats, floor
coverings, cart or transporter tires and wheels, power drive
belts, wire, and others are disposed of indiscriminately.
Small scrap articles of this type are easily discarded in
mixed trash. Tires, however, are not so easily discarded and
are usually collected separately. By comparison, waste from
the rubber products industry in the form of selvage or
rejects, is more easily collected in segregated, re-usable
form. Most manufacturers, with economic incentive, make
concerted efforts to lower their costs by selling this
segregated waste to reclaimers or other industries which can
use them.
Scrap rubber must be collected in a controlled way to be
efficiently reclaimed. The bulk of rubber waste that is
reprocessed today is collected by local used-tire merchants.
These merchants purchase worn out tires and tubes and
manufacturer's rejects and scrap. The used-tire merchant
sells reusable casings to retreaders and the remainder to
scrap rubber brokers. Brokers operate on a national and
international scale, purchasing scrap rubber from merchants
and making volume sales to reclaimers and other waste
rubber consumers. This system permits the waste consumer
to buy in large quantities at fairly stable prices from
established brokers instead of bartering with a number of
small merchants. Having determined their usual
requirements, reclaimers and other purchasers will usually
place standing orders with brokers who will further place
orders with merchants.
A typical example of a haphazard, costly collection of
waste rubber is probably exemplified by the victory rubber
drive of World War II. Although many millions of pounds
were collected, only a small quantity could be reclaimed.
Rubber boots with straps or buckles and bicycle wheels, for
example, were difficult to separate from the contaminating
metals and serious production problems arose from
inadequate sorting. Other than the tires and innerturbes
collected it is reported that substantial quantities of mixed
wastes were discarded after the emergency was over; the
economics precluded any future use.
PRESENT REUSE OF WASTE RUBBER
The area of significant usage of waste rubber products, and
incidentally also scrap from the rubber product industry,
occurs in three major industries Retreaders, Reclaimers, and
Tire Splitters. Retreaders, the largest of the three, extend
the useful life of worn tires by placing new tread on the old
carcass. The second largest, the Reclaimers, after removing
non-rubber components such as metal and fabric, convert
the rubber into a reusable form so it may be worked back
into conventional rubber products. The Tire Splitters cut
out small rubber parts mainly from the carcass and tread
areas of waste tires. These three significant industries
consumed waste in 1968 approximately equal to 20% of
the new rubber products produced in that year.
Table II - 2
WASTE RUBBER USED AND AVAILABLE: 1968
Billions
of
Pounds Percent
Tread Loss (Tire Wear)* 0.43 4.02
Waste Rubber Reused by: Reclaimers 0.54 5.05
Retreaders 1.56 14.58
Tire
Splitters 0.05 0.47
Total Weight Reused or
Worn Away
Weight of Waste Rubber
Left for Disposal
Total
2.58 24.12
8.12 ** 75.88
10.7
100.0
*Through oxidation and wear of tires on the nation's
highways (approximately 8 Ibs. per year per driver)
434,000,000 Ibs. of rubber polymer were converted to dust
and gas.
**Does not include weight of tires retreaded in previous
years which were discarded in 1968. Does not include waste
accumulated and not disposed of in previous years.
***Consists of approximately 10.7 billion pounds of
discarded products and 0.4 billion pounds of rubber
products industry waste rubber compound.
A more detailed breakdown, based on the two waste
categories of tires and other, is more specific as to the
quantities of each category consumed by the three waste
users and also includes new waste generated to arrive at the
overall net effect of these industries. TABLE II-3
43
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For tire waste, 1.95 billion pounds are collected out of the reduction from 6.02 billion pounds per year to 4.24 billion
total of 6.02 billion pounds available, of which 1.80 billion pounds, a 30% reduction.
pounds are used or sold to other uses. There are 0.20 billion
pounds of collected tires unsuitable for reuse for various With the projected increase in tire production and little if
reasons and which are returned to waste. Approximately any increase in waste tire usage, the percent tire waste used
0.02 billion pounds of new waste are created during the is expected to decrease from 35% in 1968 to 33% in 1974,
waste conversion. The net effect of this reuse is a waste excluding the new waste created by the three users. Figure
II-2
TABLE II-3
TIRE AND OTHER WASTE REUSE
(billion pounds)
TIRES Sub-Total OTHER Sub-Total TOTAL
Rubber Waste Available 6.02 4.27 10.29
Reclaimers Retreaders Splitters Reclaimers
Collected for Reuse 0.30 1.60 0.05 1.95 0.12
Reject to Waste 0.06 0.13 0.01 0.20
New Waste Created 0.01 0.01 - 0.02
Reused or Resold 0.20 1.56 0.04 1.80 0.12
44
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FIGURE 11-2 DISCARDED TIRE DESTINATION
PASSENGER
1968
TRUCK & BUS
1.0% TIRE SPLITTING
0.8% TIRE SPLITTING
0.02% RECLAIMED
PASSENGER*
1974
TRUCK & BUS*
1.2% TIRE SPLITTING
2.0% TIRE SPLITTING
0.01% RECLAIMED
•Based on the production of 220 million passenger tires 'Based on the production of 32.5 million truck tires.
45
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HISTORY OF THE RECLAIMED RUBBER INDUSTRY
The rubber reclaiming industry has always followed
scientific developments in the raw rubber industry with
developments of its own. It was not long after rubber trees
were commercially tapped and dry rubber marketed that a
method was devised to solvate waste latex and put it back
to good use. Later, Sir Thomas Hancock, father of the
United Kingdom's rubber industry, devised a horse driven
machine which resolved all his waste rubber into a solid
mass by pressure and heat. This enabled him to return the
waste back into the elastic thread he was producing at the
time. In 1839, the foundation of present rubber technology
came into being when Charles Goodyear discovered
vulcanization. Prior to this development, rubber items were
very responsive to weather. They became soft and
sometimes smelly in hot weather and rigid and inflexible in
cold weather. Vulcanization, or the treatment of rubber
with heat and a curative, i.e. sulfur, produced a practical
rubber product with none of these drawbacks.
A mechanical method for reclaiming rubber now came into
being and articles which did not contain fabric or very little
fabric were ground up and used as filler in new rubber. Car
springs, large molded blocks of rubber used in journal boxes
of horse cars, were a source of fabric free rubber and even
today, "ground spring" is a term used to describe any
ground up fabric free rubber.
In 1870, W.N. MacCartney heated ground scrap with a
solvent until the rubber dissolved. One of the first reclaims
was produced upon evaporation of this solvent. Even
earlier, in 1846, Alexander Parks boiled waste in Muriate of
Lime. Both these methods fell to the background while the
easier mechanical process, suitable for its time,
predominated. Following the mechanical method the next
major development was Hiram L. Hall's Heater or Pan
Process. The patent was issued in 1858. Hall ground the
rubber and placed it in shallow pans. The pans were now
placed in a closed vessel where steam was directed onto the
rubber. Although, not stated, it is believed that he also
added oils to help in the heat transfer. The Pan Process was
relatively simple. With little machinery required, a good
reclaim could be made and today approximately 34% of all
reclaim in the United States is made in this manner.
The "ground scrap" Hall used was essentially fabric free. It
came from rubber boots and shoes, the largest rubber
commodity available at that time. Family incomes were
supplemented by women and children, who pulled rubber
from the fabric at home and later sold it to reclaimers.
Rubber footwear production, at an annual rate of 1 million
pairs in 1840, was to rise to 50 million by 1900. The scrap
supply was changing, however. In 1900 carriage tires and
solid rubber truck tires appeared. Later, in 1905, the
pneumatic tire appeared. Tires, reinforced with fabric,
carbon black and heavier cures, became predominant. The
foremost problem was fabric. The stripping of rubber from
fabric by hand was now becoming impractical. Tires, the
new major sources of scrap, forced reclaimers to look for
new and better ways to recover the rubber. A new and
better way had been found much earlier however, by a
young man named Eugene H. Clapp. Mr. Clapp in 1868,
had developed and set up a small apparatus for separating
fiber by means of air. Briefly the whole rubber article was
ground up and subjected to an air blast. Here, the lighter,
more responsive fabric "blew away" from the heavier solid
or nearly solid rubber particles. Machinery was not
developed during those years to make use of Clapp's idea.
Today his air separation principle combined with fine
grinding is widely used for fabric removal. In 1873,
Guggenheim and Lowry treated rubber waste with an
8-10% caustic solution to destroy any wool present. After
washing, they treated the scrap with 15-20% sulfuric acid
solution to destroy any cotton. The resultant reclaim was
of poor quality.
In 1881, Colonel N. Chapman Mitchell secured a patent for
the Acid Process. Essentially he boiled the ground rubber
scrap in a 20% sulfuric acid solution which destroyed any
cotton and/or wool fabric present. Afterwards the ground
scrap was washed, dried, heated with oils and milled. A
study of the history of reclaiming will show that many
people had done work with caustic and sulfuric acid
solutions and as a result of prior work of others and
improperly drawn patents Mitchell was dragged into long
and costly litigation. He did, later on, form the first
company organized exclusively for the production of the
acid process reclaim. His process was used primarily for
rubber goods of low sulfur content. The acid process was
impractical for scrap high in sulfur such as tires. The excess
sulfur in tires and other goods could not be removed by the
acid but, on the contrary, would combine chemically with
the rubber during the heating process in open steam with
the result that further vulcanization instead of
devulcanization would occur. Because of this, a
contemporary development, the Alkali Process would
become the single most successful method of the time.
Arthur H. Marks patented this process in 1899. The process
involved the heating of ground rubber waste with a 3 to
16% caustic solution at 344-370°F for twenty hours. The
sulfur in the scrap dissolved into the caustic solution and
any fiber present was destroyed. The heating was carried
out in an apparatus specified in the patent. It consisted of a
closed vessel contained in another vessel into which steam
was introduced Defiberization, desulfurization and
devulcanization were completed in one step with this
process. The next year Marks received a patent for a
horizontal, rotating digester which except for a few
changes, is essentially the apparatus used to produce 58% of
the reclaim in the United States today.
This leads us to the last major development in the early
years of reclaiming. Robert Cowen was issued two patents
in 1900 on the strainer. A rubber strainer is similar to the
meat grinder a butcher uses today to produce the strands of
ground meat sold in markets. Prior to its manufacture, all
contamination had to be picked out by hand creating a
bottleneck in production. Forcing the rubber through a
screen which held back contaminants enabled the reclaim
industry to improve production considerably.
The development of the synthetic rubber industry in the
United States forced reclaimers to do considerable research
48
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on the reclaiming of blends of different rubber polymers.
Prior to synthetic rubber development, natural rubber was
the only polymer present. This rubber could be reclaimed
by heat alone. Heat however, tends to harden most
synthetic polymers. Also, the methods of grinding the scrap
had to be revised since natural rubber absorbs oils and
reclaiming catalysts much faster than synthetic rubber, the
natural rubber part of the reclaim will be more
depolymerized than the synthetic and the final reclaim will
be nonhomogeneous. To overcome this the rubber mixture
is now ground to a smaller particle size in order to present a
larger surface area for absorption. Eventually, certain
diterpenic acids were found which, in general, retarded the
oil absorption of vulcanized natural rubber scrap and
thereby permitted a more uniform distribution of
reclaiming oils in the scrap components. Finally, the use of
caustic or alkali solutions as defibering agents was almost
totally eliminated as caustic'hastened the heat hardening of
SBR rubber and other synthetics. As a result, the neutral
process is now used for defibering employing metal
chlorides such as zinc or calcium for the removal of fabric.
THE RECLAIMED RUBBER INDUSTRY
The members of this industry, more commonly known as
"Reclaimers", for the purposes of this report, are limited to
those who are predominantly concerned with the
conversion of used or rejected rubber products into
re-usable materials. These materials are usually reused in the
same or products similar to those from which they were
"reclaimed" i.e. scrap tires are reclaimed and converted to a
soft workable state wherein they are capable of being
blended into tire compounds for new tire manufacture. It is
also inherent in the reclaimed rubber industry, that some
materials are produced which are not reused in the rubber
industry but in other industries. Some examples are
adhesives, wire covering, pipe covering, brake linings
rubberized asphalts and tars. However, this is a small
portion of a "Reclaimers" operations.
There are fourteen rubber reclaiming companies in the
United States operating twenty individual plants, with a
reported employment of 1812 people (Table II-4).
Recently two of these plants were reported closed and
another is rumored to be closed in the near future. Most
"Reclaimers" are also members of the Rubber Reclaimers
Association (RRA). The RRA reported an overall capacity
of 825 million pounds per year in 1968. Historical
production in pounds and as a percent of 1968 capacity is
noted and graphed in TABLE H-5. The two plants reported
to have closed recently further reduce the capacity reported
in 1968. Previous years capacity is also known to have been
somewhat larger but was reduced to the 825 million pound
figure by the closing of two major plants, one in California
and the other in New York. The geographic distribution of
the remaining eighteen plants is mapped in Figure II-3 and
indicated a similarity to the distribution of the rubber
producers.
TABLE II - 4
RECLAIM
PLANT LOCATIONS
1. H.Muehlstein and Co.
Jersey City, N.J.
2. Uniroyal Chemical Div. Uniroyal, Inc.
Naugatuck,Conn.
3. Boston Woven Hose and Rubber Div., American
Biltrite Rubber Co., Inc.
Cambridge, Mass
4. Biltrite Rubber Co., Inc.
Stoughton, Mass.
5. U.S. Rubber Reclaiming Co.
Vicksburg, Miss.
6. Midwest Rubber Reclaiming Co.
E. St. Louis, 111.
7. Midwest Rubber Reclaiming Co.
Chester, Pa.
8. Midwest Rubber Reclaiming Co.
Barberton, Ohio
9. Centrex Corp.
Findlay, Ohio
10. Gates Tire and Rubber Co.
Denver, Colo.
11. Goodyear Tire and Rubber Co.
Akron, Ohio
12. Goodyear Tire and Rubber Co.
Gadsden, Alabama
13. Laurie Rubber Reclaiming Co.
New Brunswick, N.J.
14. Nearpara Rubber Co.
Trenton, New Jersey
15. Swan Rubber Co., Div. of Amerace Corp.
Bucyrus, Ohio
16. Bearfoot Sole Co.
Wadsworth, Ohio
17. Xylos Rubber Co., Div. of Firestone Rubber Co.
Memphis, Tenn.
18. Xylos Rubber Co., Div. of Firestone Rubber Co.
Los Angeles, Calif.
49
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19. Xylos Rubber Co., Div. of Firestone Rubber Co.
Akron, Ohio
20. B.F. Goodrich Industrial Products Co.
Akron, Ohio
TABLE II - 5
The United States Production of reclaimed rubber is listed
below as a percentage of the total capacity of the industry.
PERCENT OF
PRODUCTION CAPACITY
70.3
55.3
79.2
71.0
75.6
76.0
75.0
75.5
75.0
65.7
69.3
(67.5) (est.)
YEAR
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968 '
1969-1974
PRODUCTION
(million pounds)
581.5
457.3
655.9
591.0
628.4
630.4
618.8
627.8
621.3
545.8
575.0
560.0 (est.)
FIGURE II 3
The location of the twenty reclaiming plants presently in the United States are shown below:
50
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RUBBER WASTE INPUT
Reclaimers use two categories of waste: those items
reported in Part I as Rubber Products and whose useful life
is completed and some scrap items of the Rubber Products
Industry. In the latter category are included defective
manufactured items, selvage, cleanouts, etc. These were not
reported as original waste m Part I as they are normally
disposed of directly to a reclaimer or to independent agents
selling to reclaimers. A breakdown of the reported
Reclaimers 1968 usage in these categories indicates 43.7%
usage of rubber product waste and 7.5% of producers waste
as shown in TABLE II-6. The balance of 48.8% consumed
was not reported by composition but is known to be a
mixture of both categories. It can undoubtedly be assumed
that the total industry usage is in the ratio of 43.7% to
7.5% of product waste to producers scrap.
TABLE II - 6
1968 RUBBER WASTE USAGE BY RECLAIMERS
DESCRIPTION
WASTE RUBBER PRODUCTS WEIGHT (million pounds)
Worn Tires
Passenger
Truck, Bus, Tractor
Retread Buffings*
Tire Parts, Peelings*
Other Tire Parts
141.1
.2
.1
8.2
39.8
Inner Tube - Natural Rubber1 9.5
Inner Tube - Butyl Rubber 53.5
Sub-Total 252.4
Rubber Manufacturing Scrap
Rejected Tires* 23.9
Mechanical Product Scrap 11.2
Other* .3
Raw Polymer* 7.6
Sub-Total 43.0
Other Rubber Consumed2
Sub-Total 281.1
Grand Total 576.5
*Definitions listed in Appendix 1.
43.7%
7.5%
48.8%
100.0%
'Poundage shown contains a small quantity of factory
rejects for which there is no separate data.
2Composition not reported but known to be a mixture of
worn products and manufacturer's by-products.
Road worn tires are generally available in sufficient
quantity within 300 miles of individual reclaim plants. This
does not apply to the concentration of plants in the Ohio
area. The delivered cost of tires may vary from $7-14 per
ton depending on freight costs.
Tires other than passenger types, such as truck, bus, and
off-the-road are also generally available in quantity with the
delivered cost being approximately equal to the passenger
tire. Reclaim usage of these larger types is small however,
due to the added handling and processing costs.
Retread buffings are readily available as a source of ground
rubber without fiber. The cost is approximately $25-35 per
ton depending on freight charges.
Tire parts are a by-product of the Splitting Industry. They
are a good source of fabric free tire treads or "peelings".
Tire carcass selvage has value approximately equal to worn
tires. Natural rubber innertubes are restricted in availability
as production of these tubes is now limited. Due to demand
for this type reclaim for adhesives, scrap prices are $ 120 to
$160 per ton. Considerable quantities of this scrap are
imported to meet the demand. Butyl rubber innertubes,
more available than natural tubes, are at a slightly lower
cost of $100 to $120 per ton. Considerable quantities of
butyl rubber tubes are also imported to fill demand. Scrap
collection costs and procedures for both types of tubes
restrict higher use of domestic scraps.
Most producers scrap tires are directly shunted to
reclaimers at a price comparable to price of worn tires.
Without exception this is the case where the tire
manufacturers have an internal reclaim plant. Only steel
reinforced tires and tires with safety barriers are discarded
as these are too difficult to reclaim with existing
equipment.
Other than road worn tires and innertubes, little, if any,
other used consumer type rubber products are collected
and reprocessed by reclaimers. Any consumer type rubber
products which are used consist mainly of factory rejects
and selvage types which are picked up at the factory. Only
in this manner can collection costs be held down and
products grouped into categories which can be handled and
processed by the reclaimers into suitable reclaims, i.e. two
different items such as a rubber mat and a hot water bottle
may require different reclaiming chemicals and processes.
Prices for scrap depend largely on type, color and
transportation costs and will vary from $ 15 to in excess of
$100 per ton.
Sophisticated elastomeric polymer products such as those
made from silicones and fluoroelastomers, are presently
small in comparative volume. Availability is again restricted
to the factory reject type of scrap. More particularly here,
cross contamination with other types of polymers would be
particularly disastrous negating many of the advantages of
reclaiming these types of polymers. Due to their specialized
nature, these polymers are usually reclaimed on
consignment for the company supplying the scrap.
51
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Raw polymers as a by-product from polymer producing
plants are available in considerable quantity. Costs vary
depending upon the type and transportation.
INDUSTRY SOLID WASTE
Since the Reclaim Industry normally literally "feeds" on
waste, the solid waste produced by the reclaim industry
itself consists of that portion of the original waste which
cannot be converted into a reusable product.
During 1968, the Reclaim industry converted
approximately 576 million pounds of waste rubber
products and Rubber Product Producer waste into
approximately 574 million pounds of saleable, reusable
products. During the conversion, 75 million pounds of solid
waste were generated. The majority of this waste, however,
consisted of nonrubber components removed from the
waste taken in.
TABLE II-7 summarizes the sources of solid wastes
generated by the Rubber Reclaiming Industry itself and
FIGURES 11-4,5,6 illustrate the sources of these wastes in
the three major reclaiming processes as well as the flow of
materials thru these processes.
The weight of oils and compounding ingredients which
were later added into the rubber product to assist
production and meet customer needs, nearly equaled the
weight of nonrubber and waste components removed.
UNCONVERTED WASTE (62 million pounds)
Thirteen million pounds of ferrous and nonferrous scrap
metals were removed from the waste rubber taken in. The
ferrous metals, mainly the steel bead wire from tires, may
be reused during periods of need and high scrap steel value.
The need has presently been reduced, partially by the new
technology of steel production.
The nonferrous scrap has been more readily reused. The
copper innertube stem scrap which is the predominant
nonferrous scrap, having a higher value, is more easily
reused. The weight of textile and textile-rubber mix
separated from the original waste came to 37 million
pounds in 1968.
The textile fibers partially separated from worn tires are
usually a mixture of all types of fibers used in tire
manufacture. This will include rayon, nylon, polyester and
glass with a small amount of cotton. As new fibers are
introduced into tire manufacture, they will show up in the
textile mix.
Due to the mixed nature of the textiles, the amount of
entrained rubber carrying over, and the short length of the
fiber normally coming from conventional fiber separation
equipment, the mix has little value for reprocessing. It may
have some value or usage potential in nonwoven mat
applications i.e. insulating board. Another considered area
is as an agricultural mulch.
The waste rubber discarded (12 million pounds) is
predominantly unusable scrap tires consisting of the
studded snow tire or steel wire belted types. These are
sorted from shipments of worn tires and discarded. It is
highly doubtful that development of methods to convert
these into reclaims would effectively reduce waste.
NEW WASTE (13 million pounds)
Packaging material waste amounted to 8 million pounds in
1968. Packaging waste is usually reduced by bulk handling
of all materials and by reusable containers. These aspects of
material handling are beyond the scope of this report.
Other scrap (5 million pounds) involves office paper,
pallets, strapping and miscellaneous items which are typical
in many other industries.
TABLE II - 7
RECLAIM INDUSTRY SOLID WASTE -1968
Description
From Original Waste
Ferrous & Non Ferrous Metals (a)
Textile & Textile-Rubber Mix (b)
Rubber (c)
Sub-Total
New Waste
Packaging Materials
Other
Sub-Total
GRAND TOTAL
Weight
(Million Pounds) %
13.2
37.1
11.6
61.9
8.0
5.3
13.3
75.2
17.6
49.3
15.4
82.3
10.7
7.0
17.7
100.0%
(a) Predominantly ferrous bead wire from tires, remainder
mainly nonferrous value stems from natural and butyl
tubes.
(b) Textiles and Textile-Rubber mixtures predominantly
from processes using mechanical separation of textiles from
rubber. Source mainly from tires.
(c) Predominantly worn tires which cannot be suitably
reclaimed, i.e. studded winter snow tires and steel wire
re-inforced tires.
52
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FIGURE II 4 DIGESTER OR WET PROCESS
Scrap Delivery
RAW MATERIAL'
RECEIVING
AND
SORTING
RUBBER WASTE
Tites dumped consisting of those
which cannot be reclaimed with
existing equipment or those
uneconomical to leclaim. Examples
are studded tires, steel reinforced
tired, etc
OTHER WASTE
CRACKING, COARSE
AND
FINE
FIBER
SEPARATION
COMPOUNDING
DEVULCANIZATION
COMPOUNDING
During
matelv
are ai cf
d^SISt II
give the
REFINER
TUBER
FINISHER
TESTING
PACKAGING
AND SHIPPING
Waste generated in the form of
cartons, pallets, and strapping
Bead wire and adhering rubber
Weight of reinforcing fiber stripped
from t ire along with rubber
particles adhering to this fiber
Estinidted loss through handling,
machinery, processing, materials
handling equipment
ness
J jxiunds of nidtpi ials
to the tracked stock to
. di'vulciini/jtiuM and to
1,1) fHodtitt some of its
Portions of slock removed for
quality control are usually reworked
Waste paper and containers which
are generated during the two
compounding steps
Waste paper, talc black, limestone,
mill leakage, tuber screens which
cannot be reworked
Scrap generated in testing services
area (General office waste) Broken
pallets, waste talc
TOTAL PRODUCT
06 Ibs
25 3 Ibs
RUBBER WASTE
OTHER WASTE
•If the raw material does not contain any reinforcing fabric or metal, this weight (50+ 190 Ibs) will be deducted from th«
OTHER WASTE total and added with additional compounding ingredienti to the total product weight
53
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Scrap Delivery
FIGURE 11-5 PAN OR DRY PROCESS
RECEIVING
AND
SORTING
Raw Material*
100 0 Ibs
990
Rubber Waste
Stock which is dumped It consists
of scrap which cannot be reclaimed
with existing equipment or scraps
which have deteriorated or have
been contaminated
Other Waste
VALVE STEMS
(removed by
hand)
VALVE SEATS
AMD PATCHES
(removed by
hand)
02
Packaging waste such as metal
straps, pallets, and cardboard
boxes
Stems are removed and sold as
scrap metal
CRACKING
COARSE AND
FINE
Patches and seats are made of
several types of rubber and may
contaminate the stock They are
dumped
Raw stock is flushed through the
cracking system to remove any
contaminants The contaminated
flushing material is dumped
COMPOUNDING
DEVULCANIZING
During this step, 7 7 pounds of
ingredients are added to the
cracked stock to assist m the
devulcamzation and to give the
final product some of Its
properties
REFINER
TUBER
FINISHER
Estimated loss of devulcamzed
stock through handling, i e
bucket loaders, conveyors
Portion of stock removed for
quality control testing Usually
not set aside to be reworked
Waste generated in this section
tt consists of empty paper bags,
cartons, and other containers, a
majority of which is paper
Waste paper, talc, black limestone.
mill leakage, tuber screens whtch
cannot be reworked
PACKAGING
SHIPPING
Scrap generated in testing
services area Usually in form of
waste paper (general office waste)
Broken pallets, waste paper, talc
TOTAL PRODUCT
1 9 Ibs
24 Ibs
' RUBBER WASTE
OTHER WASTE
*Th» raw material used in this example consists of inner lubes.
54
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FIGURE 11-6 RUBBER CRUMB PROCESS
Scrap Delivery
RECEIVING
AND
SORTING
Raw Material*
100.0lbs.
99.3
-0.7
Rubber Waste
Stock loss usually due to
deterioration or discoloring of
material, contamination, or
discontinuance of product line.
Other Waste
-0.2
Waste generated in form of waste
paper, wire strapping, broken
pallets, etc.
CRACKING
COARSE AND
FINE
99.1
-0.2
98.9
-0.1
Raw stock is flushed through the
system to remove any contamination.
This flushing material is
discolored and/or contaminated
and cannot be used. It is dumped.
Estimated loss through machinery
and materials handling equipment.
TESTING
98.8
0.1
0.1
Portion of stock removed for
quality control testing.
Scrap generated in testing
services. (Usually in form of
general office waste)
SHIPPING
AND
PACKAGING
98.7
0.1
Broken pallets, waste paper,
talc, strapping.
TOTAL PRODUCT 98.7 Ibs
1.1 Ibs. = RUBBER WASTE
0.4 Ibs. = OTHER WASTE
* The raw material used in this chart consists solely of rubber polymer which does not contain any reinforcing fabrics or
metals. If the raw material selected does contain metal or fabric then the weight of this material must be deducted from the
final product weight and this separated metal or fabric becomes other waste.
55
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THE RECLAIMING PROCESSES
An indication of the state of technological development of
the reclaims industry can be obtained from a study of the
reclaim processes. The following processes are itemized in
chronological order of events leading to the reclaiming of
waste rubber. However, not all reclaimers may use all of
these processes nor the same equipment. The individual
process and its equipment may vary from company to
company but the end result is comparable. Items such as
product blowers, conveyors, manpower, numbers of
machines and their productivity, in-plant trucking, storage
areas, inspection stations, cleaning and maintenance
stations are not included but are assumed to be required at
the discretion of the reclaimer.
The three basic processes used are digester (wet),
devulcanizer (dry) and mechanical. A generalized material
flow pattern for each process indicates the differences
between each (Figure II-7). All three processes do contain
some common steps and process equipment. The first step
is to separate the many wastes into four basic streams such
as tires, tubes, mechanical scrap and miscellaneous. Part of
this step includes the removal of the brass and steel valve
stems from the tubes and these stems are either sold or
discarded as waste. Also, the bead wire from the tires is
removed and discarded as waste. These metals were once
more widely sold as recoverable waste. The metal removal is
usually done manually but some bead wire is removed by
machine.
After separation, the wastes are size reduced, through two
basic types of machines, crackers or hammer mills. The
cracker is a two roll machine, having working roll lengths of
30" to 42" and diameters of 18" to 32" depending upon
the individual reclaiming company. Each roll is corrugated
or fluted axially and each roll rotates at a different speed to
effect a friction ratio. As the waste is dropped into the
cracker, the two rolls, which rotate in opposite directions,
force the waste to pass between them. The slower roll
corrugations momentarily "hold" the waste while the faster
roll corrugations shear, slice, crush and abrade the waste
much like a pair of scissors. The process continues until all
the material passes through a classifying screen of some
predetermined size. Some reclaimers further reduce the
waste size down to less than 10 mesh having secondary and
tertiary crackers. As the size of the waste becomes smaller,
the corrugations or flutes on the cracker rolls become
smaller and smaller to increase the grinding efficiency. If
tires are the waste material, the separated bead wire which
serves to hold the tire firmly to the rim of the automotive
wheel, is removed by hand after two or three passes
through the crackers unless the bead wire was cut out
before the size reduction process. The action of the two
rolls actually peels or scrapes the rubber off the wire,
leaving only residual amounts with the metal. The bead
wire is then scrapped.
The term hammer mill covers a family of several machines,
in essence a high speed rotating drum which either hammers
or impinges the scrap with pivoting "T" or "I" bars or with
knives mounted on the periphery of the drum. There may
be stationary knives located on the frame within which the
drum revolved, with or without a perforated screen or plate
that retains the scrap in the work area until the scrap is
size-reduced to pass through the screen or plate. The
machine containing drum knives, may have a special feeding
device at the inlet side of the machine to control the input
feed of a long strip or the like, to uniformly control the size
of slicing much like a meat slicer.
Once the size reduction process is completed, the fiber
containing wastes may require either the additional process
of mechanical fiber separation or chemical degradation and
washing out of the fiber in the wet process. This washing
sequence creates an effluent problem. The mechanical
separation sequence is used by most reclaimers to
circumvent the water pollution problem inherent in the
digester or wet process. The fiber separation and fine
grinding process is, therefore, associated primarily with
scraps which contain reinforcing fiber materials such as
cotton, rayon, nylon, polyesters, fiber glass and metal. In
order to efficiently size reduce the waste before the actual
reclaim process, the scrap must be separated from the
reinforcing materials immediately after the initial size.
The input stream to the fiber separation process is first
separated into different particle sized streams by a screener
with several screen decks. These streams are fed onto air
separation tables which effectively separate loose fiber
pieces from clean rubber pieces by vibration and air
flotation. The entire band of rubber/rubber-fiber/fiber is
broken up into separate streams where the clean rubber is
removed from the system. The fiber and rubber-fiber pieces
are then fed into hammer mills for a hammering or scraping
action. The degree of scrapping and size reduction is
governed by the peripheral screen or perforated plate. After
the material has been hammered or scraped sufficiently to
pass through the screen, it is then fed to sifters or beaters.
These machines, by a gentle beating, permit loose particles
of rubber to be separated from the fiber and pass through a
retaining screen while the fiber is conveyed to the end of
the beater. The separated rubber is sometimes considered
clean and is removed or if not clean enough, it is recycled
to the screeners. As to the fiber, it is recycled either to the
screener or to another set of hammer mills.
The last phase of the fiber separation process is baling the
waste fiber that is removed from the scrap. This baled fiber
is usually made up of small strands, less than 1W long, and
contains a very small amount of entrapped rubber. If there
is a market for this fiber, it is reused, otherwise it is
discarded. In some instances, the fiber is further processed
by passing it through a carding machine to further cleanse
the fiber for reuse.
The fiber separated rubber is conveyed to a storage bin for
further size reduction. This size reduction is in the form of
fine grinding. Crackers, much like those used in primary
size reduction, with very small axial corrugations permit
size reduction of the rubber to -30 mesh or smaller.
Hammer mills as described earlier can also be used for the
finer grinding of the rubber but are not as efficient as
crackers.
56
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FIGURE 11-7 RECLAIMING PROCESS CHART
TIRES
TUBES
RUBBER WASTE
PRIMARY PARTICLE
SIZE REDUCTION
SECONDARY PARTICLE
SIZE REDUCTION
FIBER SEPARATION
FINE GRINDING
COMPOUNDING
MECHANICAL
WASTE
MISCELLANEOUS
CRUMB
BAG-SHIP
\
STING
ROCESS
IVTER
=IY
DEVULCANIZING
DRY PROCESS
MECHANICAL
PROCESS
. 1 .
MILLING
MILLING
t
1'
SLABS
1
BALES
INSPECT TEST-SHIP
57
-------
Material that has gone through the crackers or hammer
mills is then screened. Particles that pass through the
screens are considered product while the remaining material
is recycled for further size reduction. This clean and fine
ground rubber crumb is now ready for the heat of the
reclaiming or softening (devulcanization) process.
The three processes used for reclaiming and the
approximate percentage of reclaim made by that process
are as follows:
Digester or Wet Process 58%
Devulcanizer or Dry Process 34%
Mechanical Process 8%
The actual reclaiming process is basically a softening of the
rubber scrap for reuse in other products.
In the digester or wet process, an agitated vessel, usually
jacketed for heating, is used. Scrap is placed in the vessel
with water and reclaiming oils, heated for a specified time
and then discharged as a slurry into a blowdown tank.
The blowdown or discharged rubber is extremely hot
causing the vapors to be superheated. These vapors are
subsequently condensed and the volatile oils recovered for
reuse. Air pollution is virtually eliminated. The now
softened rubber is mechanically de-watered and dried by
various means such as hot air ovens, tray dryers, etc. prior
to further processing. In this process, scraps used usually
contain reinforcing fabric which is degraded and washed
out by the action of the water, chemicals, and heat.
The devulcanizer or dry process is the second most
important reclaiming process, and is used when there is no
reinforcing fibers included in the scrap, such as tire
innertubes, mechanical scrap or fiber separated fine ground
tire scrap. In this process, fine rubber particles are premixed
with reclaiming oils and placed in stacked shallow pans, or
in an open cylindrical boat, both of which are usually
mounted on wheels so that they can be rolled into a
horizontal autoclave. After a heating period, the autoclave
is opened and the reclaimed or devulcanized scrap is
unloaded and cooled, ready for further processing.
Generally there is no need to dry the discharged material
unless the steam used is not superheated.
The mechanical reclaiming process, unlike the other two
preceding processes, is continuous and also uses fabric free
wastes. The fine ground wastes are continuously fed into a
high temperature-high shear machine with the reclaiming
oils. The rate of devulcanization is controlled by the speed
of a screw, while the compression and temperature is
maintained constant. The discharged reclaimed rubber
needs no drying and is ready for further processing.
The reclaimed or softened rubber from any of these
processes is rarely used without subsequent compounding
which is necessary to impart special physical properties to
the finished reclaims. There are many types of machines to
mix the compounding ingredients into the softened rubber
before final processing. The actual ingredients to be added
are in the form of low and high viscosity, heated and
unheated liquids; granular and powdered fillers, pellets, etc.
These ingredients must be thoroughly dispersed into the
softened rubber. The mixers most commonly used to
incorporate the fillers into the rubber are either horizontal
or vertical ribbon, or conical rotating blenders. The
horizontal mixer, the most popular, is an enclosed
rectangular box with a rounded bottom having the mixing
accomplished by a horizontally driven continuous ribbon,
paddles or the combination of the two. Some units are
batch mixers while others are continuous, depending upon
how the inlet and discharge ports are positioned and the
length of the machine. Conical rotating blenders are
cylindrical with the entire enclosure rotated between
centers concentrically or eccentrically.
Once the rubber and compounds are mixed, these materials,
must be intimately blended and massed. This is sometimes
done continuously, as in the mechanical reclaiming process,
but in the other processes it is done separately. The two
basic massing machines used are the Banbury and the
extruder. The Banbury is a heavy duty machine with
counter-rotating blades that is self-cleaning and imparts a
high shear to the feed material. The shear may be altered by
moving the ram up or down to change the pressure exerted
on the material being massed. This machine is a batch type
but recent developments can make these machines
continuous by the use of twin screws to feed the material
into the body of the Banbury. Usually it takes between 1 to
3 minutes to mass the material in the batch machine while
the continuous unit does it in a shorter time. The other
massing machine, the extruder, is much like any other
extruder except that for rubber massing, a compression
ratio of 3:1 to 5:1 is required and the length to diameter
ratio is much higher. It is a continuous process machine and
more reclaimers are converting to this mode of massing.
The massed reclaim is then refined and strained to complete
the process. Refining imparts a smooth uniformly clean
quality to the rubber, with the rubber sheeted into a very
thin film from .002" to .010" thick. The strainer removes
foreign materials such as glass, metal, wood or sand from
the rubber, using screens of 10 to 40 mesh opening. The
amount of milling depends upon the size of the reclaimed
rubber particles and the degree of milling required by the
customer. The finer the grinding in the earlier processing,
the less refining is required.
The strainer is a heavy duty extruder with the screw seldom
exceeding a 2:1 compression ratio. Some strainers have
flared heads to increase the screening area and capacity,
while others have hydraulic or electric activated heads to
permit faster screen changing.
Refiners or refining mills are similar to the crackers
described earlier, except the rolls are smooth. Some
reclaimers refine their rubber with only one pass through
the mills while others pass the rubber through mills for
three or four passes. In these cases, the rubber is milled for
the extra passes to smooth out the large rubber particles
and to form a relatively thin sheet which can then be
strained. After straining, the rubber may be given more
58
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passes in the mills to further squeeze the small rubber
particles to form a very smooth homogeneous sheet.
The finishing operation may be combined with the refining
and straining but for clarity it is separated in this report.
Each reclaimer may complete his reclaiming operations in
either of two ways — by sending his product to the
customer in the form of slabs, stacked on pallets, or in
bales. Slabbed reclaim is made on a mill and the discharged
sheet is wrapped on a rotating drum of a specified diameter,
until the proper thickness is required. The wrapped layers
or sheets are then cut off the drums, forming a solid slab of
a certain length, width, and weight. The slabs are then
dusted to prevent sticking to each other, tested and shipped
to the customer. Baled reclaim, is similar in the milling
sequence, except the thin milled sheet is conveyed to a
baler, where the rubber is compacted to form a bale. The
bale is then encased in a bag, stacked on a pallet and sent to
customer after testing.
Another reclaim process not discussed in detail is crumbed
rubber waste (Figure II). This material is any type of
non-reinforced rubber, not softened like regular reclaim,
but finely ground in cracker mills to a very discrete particle
size, bagged and sent to the customer.
TRENDS IN THE RECLAIM INDUSTRY
Despite the steadily increasing production and use of
rubber products in the United States, the trend is
downward for recycle or reuse of waste products as reclaim.
As a percent of new rubbers produced, reclaim has declined
from 19% in 1958 to 10% in 1968. (Figure II-8) Some of
this reduction is probably due to development of new
rubbers not compatible with present reclaims.
Undoubtedly, the major reductions were caused by cost,
quality, or esthetic reasons. A comparison of the reclaim
usage in 1960 with 1967-'69 (TABLE II-8) indicates
substantial reductions in some usages by application.
Competitive materials as rugs, colored plastics have reduced
usage in automotive mats and mechanical parts from 105
million pounds in 1960 to approximately 55 million
pounds. Similar reductions are noted for other mechanical
goods, hose, shoe heels and soles, and hard rubber products.
In general the tire and innertube application consumption
has remained virtually constant at the 380 million pound
level.
Whole tire and butyl reclaimed rubbers are incorporated in
innerliner compounds to reduce cost, improve processing
and improve air retention (butyl reclaim).
Improved compounds and constructions which minimize
the liner requirements have resulted in some reduction in
liner compound and also the reclaim. Increased flexing and
heat buildup caused by lower tire pressures, low aspect
ratios, and higher speeds have resulted in a trend towards
the substitution of new rubber for the reclaimed rubber in
the innerliner.
FIGURE 118 RECLAIM CONSUMPTION AS A PERCENT OF TOTAL NEW RUBBER
20
16
12
10
1958
1960
1962 1964
59
1966
1968
-------
TABLE II-8
RECLAIM CONSUMPTION BY PRODUCT
Tire & Tire Repair Mat'l
Innertubes
Auto Mat & Mech
Hose, Belt
Mechanical Goods
Non Automotive
Cements & Dispersions
Heels, Soles
Hard Rubber
Rubber Surface
All Other
Total
*RRA Estimate
'60
380.6
104.8
36.1
52.6
15.7
17.0
26.2
22.9
655.9
'67
364.3
15.2
55.8
26.2
31.8
16.4
8.7
14.3
4.9
11.0
548.6
'68
385.3
30.0
57.6
24.9
23.5
18.4
11.4
7.4
5.1
12.1
575.7
'69*
377.4
18.6
55.3
31.8
32.9
19.7
5.6
6.7
3.3
8.3
559.6
Despite the usual cost reduction and improved processing
advantages to tire carcass production, the increased heat
buildup reported for these compounds containing reclaimed
rubber has resulted in some reduced usage in carcass
compounds. Sidewall compounds which have traditionally
contained large amounts of reclaimed rubber to control
shrinkage of the extruded sidewall, eliminate mold blemish
and lower costs, are also undergoing a trend towards
reduced usage. This again is due to the requirement for
compounds with increased resistance to the flex cracking
brought about by the increased flexing in lower pressure
tires, wide oval types, and the increased ozone
concentrations in the atmosphere. The low abrasion
resistance of compounds containing reclaimed rubber limits
its use to very low levels to control shrinkage in the first
line treads. Larger amounts of reclaim are used to lower
costs of lower quality tread compounds. Fine ground tire
peelings are being added to tread compounds with
satisfactory results.
The reclaimers are continuously conducting programs to
develop improved reclaimed rubbers for tire usage and
improved tire compounds utilizing reclaimed rubber.
However, the speed with which major changes in tire
constructions are being made, particularly toward
constructions with increased flexing, has made instant
demands for compounds with improved physical properties
which the tire compounders have often obtained by
reducing the amount of reclaimed rubber. The relatively
low price of reclaimed rubber does not seem to provide the
incentive for these compounders to increase the usage nor
do the low profits of the reclaimers justify additional
expenditures to carry out the necessary development
program.
Some of the required developments include:
1. Improve resistance to flex cracking in liner and sidewall
compounds.
2. Improve low and high temperature liner compounds.
3. Study of reclaim in carcass compounds.
4. All of the above will require both laboratory work and
extensive service tire testing.
5. Lower cost reclaim rubber.
A number of other products which have traditionally used
large quantities of reclaim are also using less reclaim at the
present time.
Hard core soft tread tires are being molded from
compounds containing lower levels of reclaimed rubber and
are also being replaced by plastics in many applications.
The change from calendered black rubber to carpet and
plastic mats in automobiles and trunk mats has resulted in a
large cut-back in reclaimed rubber usage.
More competitive synthetic rubber prices are allowing the
compounding of semi-pneumatic tires with low levels of
reclaimed rubber thus reducing usage in a previously major
market.
The light colored natural rubber scraps required for
reclaimed rubbers for cements and dispersions are no longer
in constant supply and scrap costs are generally high,
effectively restricting the production of these reclaims.
Light colored synthetic scraps cannot be formulated into
reclaims for adhesives due to limited tack and solubility and
are generally too high priced for use in reclaims to compete
with new SBR.
Ground rubber waste has many present reuse applications
due to its lower cost. Without any additional reclaiming
costs other than segregation, fiber or metal contamination
removal, and grinding, it is useful and competitive to other
60
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materials for molded rubber applications. The lower
transportation cost advantages of bulk shipments of this
crumb rubber cannot easily be achieved due to the ICC
regulation classifying this material with a yellow label as
inflammable.
Reclaimed rubber formerly used in hard rubber products,
battery cases, combs, etc. has been almost completely
replaced by new rubbers and plastics due to the lower and
product cost possible with these materials.
In general it can be seen that the low SBR prices are
allowing compounding in competition with reclaimed
rubber and until there is a definite economic advantage for
reclaimed rubber no trend toward increased usage can be
anticipated.
PROCESSING ADVANTAGES AND COST SAVINGS
The use of reclaimed rubber whether as a source of rubber
hydrocarbon or as a compounding ingredient will usually
result in compounds with lower overall costs and improved
processing characteristics.
Traditionally one of the main advantages of reclaimed
rubber has been the competitive lower cost. This is no
longer true with respect to material cost due to the low
priced, oil extended synthetic rubbers. Even with this fact
established, the stable low price of reclaimed rubber offers
an advantage in helping stabilize new rubber prices and
providing a firm base for estimating cost.
The chemical action of the reclaiming process combined
with the extensive mechanical refining and the presence of
fillers results in a product with low nerve. This low nerve is
responsible for many of the processing advantages gained
from the use of reclaimed rubber. Reclaimed rubber
compounds generally process faster in extrusion and calen -
der operations with significant reduction in shrinkage and
die swell and improvement in gauge control. Heavy gauges
can be calendered blister-free at high rates when reclaimed
rubber is added. These compounds also exhibit less heat
build up during processing and will cure uniformly in fast
higher temperature cycles.
Reclaimed rubber's low nerve can reportedly reduce the
fabricator's power costs as much as 35%. The peak
horsepower demand, which usually determines the electri -
cal cost rate, is also significantly reduced, increasing the
savings. It has been estimated from experience that a
reduction of one minute per batch in mixing time by the
use of reclaim in standard compounds reduces costs by as
much as four dollars per ton of compound and permits an
increase in thruput rates of up to ten percent.
Other dollar savings are realized from the faster processing
of extruded and calendered stocks; less rework due to
out-of-specification processed parts; short and safe high
temperature cure cycles; and fewer defective finished parts.
Following is a list of technological and marketing advances
which reclaimers recommend as ways to improve the
consumption of their products:
a) The establishment of standard specifications for
reclaims to be established by the Rubber Reclaimers
Association. Reclaimers will produce these at their
discretion for general market consumption in addi -
tion to their regular customer-oriented reclaims.
b)The improvement of abrasion resistance: Although the
reclaimers mills do a very thorough job of mixing
reclaim components, high magnification inspection
reveals "pockets" of carbon black, fillers, oils, etc.
These pockets readily abrade and a more thorough
method for dispersion must be sought.
c) Improved heat resistance. The need for products with
improved heat resistance has forced a change from
natural rubber, SBR and related reclaims to newer
specialty heat resistant elastomers.
d) Public education: The quality of reclaim should be
stressed and its false reputation as a cheap diluent
minimized. An image as a technically desirable raw
material should be emphasized. These two objectives
would be aided by the establishment of reclaim
standards for quality and performance.
RECLAIM EXPORTS/IMPORTS
The increasing availability of local scrap tires, expansion of
reclaiming facilities, and generally lower wages have re -
suited in the production of more and lower cost reclaims
outside of the United States. These factors have caused a
sharp and steady decline in the export of reclaims and are
probably also responsible for the increase in reclaim
imports. It is apparent that the overall effect will be that
imports will exceed exports in the near future and that this
change will be reflected as a reduction in domestic reclaim
production. (FIGURE 11-9)
61
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FIGURE 11-9 RECLAIM EXPORTS/IMPORTS
V)
0
z
D
O
Q.
Z
o
40
30
20
10
--- EXPORT
NET EXPORT
/' IMPORT
58 59 60 61 62 63 64 65 66 67 68
69
YEARS
62
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TIRE RETREADING
HISTORY
Tire retreading had its beginning over 60 years ago. The
first retreads were produced by cutting off the remaining
old tread, buffing the surface and applying a layer of
vulcanizable cement on the tire. Then a tread which had
been previously vulcanized was buffed, cemented and
placed around the tire. A flexible steel coil was placed
inside the tire and the assembly was wrapped with canvas
strips like a bandage. The tire was then placed in a kettle or
tub and vulcanized with live steam. In 1912 "Dry Tread
Cures" were introduced. Here, an unvulcanized tread was
placed on the buffed tires. The tires were then placed in a
quarter circle mold where a portion of the tread was cured.
After one section was cured the tire was turned in the mold
and the cure continued until all sections of the tread were
vulcanized. Heat was supplied by coal or gasoline fired
boilers. The pressure necessary to vulcanize the rubber to
the tire was applied by clamps and sand bags placed inside
the tire. In the early 1920's the first full circle retread mold
appeared and retreading began to progress. By 1926 a mold
in the shape of a circular heater was introduced that, fitted
with various aluminum forms, could retread several sizes of
tires. This was developed into a clam shell type of mold
with boilers operated by a small gas or oil burner.
THE RETREAD INDUSTRY
A retreader converts worn tires by applying new tread
compound in such a manner as to make the tire reusable.
Depending on the number of times the individual tires are
retreaded, the useful life of the original tire is substantially
extended.
In the years 1930 to 1940 passenger tire retreading grew at
a rate of 10% per year. By 1944 - when World War II
production was at its height — retreads accounted for 30
million units. Following a large drop in production after the
war, the retreading industry has since grown at a rate of
approximately 3% per year.
The estimated number of passenger car tires retreaded
increased from 29.9 million units in 1958 to approximately
36 million units in 1963 and has remained fairly constant
since that time. The larger sized truck tires retreaded has
increased steadily from 7.3 million retreads in 1958 to 9.7
million in 1968 (TABLE II-9).
A comparison of retread versus new tire production
indicates retread passenger tires constitute approximately
17% of tires in use. Retread truck tires constitute 28% of
tires in use. Without the retread industry, all tires now
retreaded would have been added to solid wastes in the year
retreaded and new tire production would have been
increased to replace them, adding still further to the solid
waste disposal problem.
TABLE II-9
PRODUCTION OF RETREADED TIRES
(Millions of Tires)
Passenger Car Truck
Tires
1958 29.9 7.3
1959 32.4 7.6
1960 30.6 7.4
1961 31.9 7.6
1962 34.5 7 7
1963 36.3 7.5
1964 36.0 8.0
1965 36.0 7.6
1966 35.3 8.0
1967 34.5 9.3
1968 35.8 9.7
1969* 36.5 10.0
*Estimated
There are approximately 8,500 retread plants in the United
States of which 8,000 are independent dealers and
retreaders. The balance are operated by large tire companies
and other mass marketing organization or chains.
The estimated daily capacity is 211,650 units, equivalent
on an annual basis to 50-60 million units depending upon
the number of days operated. Capacity utilization is then
calculated to be approximately 85%.
Usage of Rubber Waste
A majority of retreaders receive their tires from scrap
dealers. The next largest source for retreaders is turn-ins,
tires left at the store when replaced by new ones. Steel
reinforced tires are presently being retreaded, however
studded tires are done only on request from specific
customers.
Tires actually successfully retreaded and put back into
service accounted for 1.242 billion pounds recycled in 1958
and 1.560 billion pounds for 1968. (TABLE 11-10). This
usage does not include any units rejected as being
unsuitable prior to retreading or the estimated 3% rejected
after retreading. Usage is calculated by multiplying the
number of reported retreaded tires by 23 pounds for
passenger tires and 76 pounds for truck tires. This is the
average original weight minus 8% and 9>l/i% tread loss
respectively.
65
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TABLE II-10
WEIGHT OF WORN TIRES USED IN RETREAD INDUSTRY
THOUSAND OF POUNDS*
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
Passenger
tires
687,700
745,200
703,800
733,700
793,500
834,900
828,000
828,000
811,900
793,500
825,400
(839,500)
Truck
tires
554,800
577,600
562,400
577,600
585,200
570,000
608,000
577,600
608,000
706,800
737,200
(760,000)
Total
1,242,500
1,322,800
1,266,200
1,311,300
1,378,700
1,404,900
1,436,000
1,405,600
1,419,900
1,500,300
1,560,600
(1,599,500)
(Estimated)
*The tread rubber added to the casings is included in the
10.7 billion pounds of new rubber products manufactured
in 1968.
Very little solid waste is created by the retread industry.
The largest waste item is tread buffings generated during
the preparation of the tread surface prior to application of
the new tread. The old surface is buffed with wire brush
wheels hence the term "buffings" for the abraded rubber
dust. Approximately 1V4 pounds and 4 pounds of buffings
are produced from passenger and truck tires respectively.
Calculated buffing weights based on tires processed indi -
cates a waste increase from 74 million pounds in 1958 to
92 million pounds for 1968, or approximately 6% of the
weight of the waste tires recycled (TABLE II-l 1).
TABLE II-l 1
BUFFINGS PRODUCED ANNUALLY
Millions of Pounds
Passenger
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
44.9
48.7
45.9
47.8
51.7
54.4
54.0
54.0
52.9
51.7
53.7
*54.8
Truck and Bus
29.1
30.5
29.7
30.3
30.9
29.9
31.9
30.2
32.7
37.1
38.8
*40.0
Total
74.0
79.1
75.7
78.1
82.6
84.3
85.8
84.2
85.1
88.8
92.5
94.8
In 1968 reclaimers reported using 97,378 pounds of these
buffings equivalent to less than 1% of years total. It is
known however, that substantial quantities of this material
are used in other industries i.e. brake lining, asphalt
composition, etc. No reported data is available.
Rejected retreaded tires amount to about 3% of those
retreaded. This is equivalent to 550,000 pounds of waste
per year consisting of approximately 90% old waste tires
plus 10% of new tread rubber added to tire.
Less than 5% of total industry waste has been reported as
being from packaging materials. This is equivalent to
approximately 4 million pounds per year.
Total industry waste in 1968 was 99.3 million pounds of
which 95 million pounds was unused tire waste (TABLE
II-12).
TABLE II-12
Total Waste From Retreading Industry - 1968
Thousand of Pounds
From Waste Tires
Buffings
Rejected Retreads
Subtotal
New Waste
Packaging
GRAND TOTAL
weights
94,750
550
95,300
4,000
99,300
PROCESSES
"•Estimated
The retreading of a tire today involves several steps. First
the old tire is inspected. Without a sound casing or tire
carcass all other production efforts and controls are of no
value. There must be no cuts or deterioration of the
reinforcing fabrics. Air is injected into the shoulders of the
tire to detect hidden ply separations, the major cause of tire
failure. The tire is now vented in the bead area. This will
allow trapped air to escape during the molding process or
during highway flexing. Any trapped air could expand to
cause ply separation. The tire is now buffed. All the
remaining tread is ground off in this step. After buffing, the
crown is cleaned with a stiff wire brush to remove any
rubber dust. The next step is to measure the tire. Tires have
a tendency to "grow" after some road use. This growth can
amount to 7% of the tires original width. After this
measurement, the wall thickness of the tire is determined.
This is necessary in order to select the correct curing rim
and assure a tight fit of the tire in the matrix. Vulcanizable
rubber cement is now sprayed on the tire. Strips of tread
rubber are wound circumferentially around the tire. This
tread rubber called "fast cure", was introduced in 1957 and
66
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cuts the vulcanization time 20%. From here the tire goes
into the mold where is is cured. Later it is inspected and
made ready for delivery. One third of the retreaders today
"program" the tread on. In this method, a thin strand of
tread stock is slowly wound around the tire. The machine
operator selects the profile he wants built onto the tire and
the machine automatically wraps the rubber strand around
until the exact contour is built up. The curing and
inspection steps follow.
The next major process in use is called the "Bandag". It is
used primarily on truck and bus and larger tires. The tire is
prepared as usual and a partially cured tread is placed on
the tire. The tire is now cured in a much shorter time. The
shorter cure helps to extend the life of the tire as heat
deteriorates the tire rubber, and also weakens the fabric. A
shorter cure time has another advantage in that it helps to
achieve better production rates from expensive curing
apparatus.
TRENDS IN THE INDUSTRY
There are many factors that are limiting the retread
industry growth and hence the reuse of road worn tires. (*)
It was noted that passenger tires retreaded have plateaued
out at approximately 36 million units from the period 1963
to the present. The main growth in units recycled has been
in the larger size, truck tires. However, in terms of percent
of new tires recycled, passenger tires have dropped from
25% in 1963 to 17% in 1968. Truck tire recycle has also
dropped from 32% to 28% (FIGURES 11-10 and 11-11).
There are many reasons for this lower reuse of waste tires.
In general, the average passenger tire customer views
retreads as a "second class citizen" of the tire world. This
connotation evidently arises from the idea that "used"
materials are always inferior to new materials regardless of
the quality of the new materials. With respect to tires, it
may also be related to some poor customer experience as
far back as the customer may remember, possibly to the
post World War II period before the industry reached its
present level of sophistication. The growth of units recycled
in truck and airplane type tires however tends to negate this
type of thinking. Users of these tires are looking for service
and cost and are not hesitant to retread tire casings more
than one time if possible.
The apparent reluctance to accept retreaded passenger tires
as readily as truck type tires are accepted may be valid by
reason of quality differences. It has been noted that these
larger tires require larger equipment and hence may only be
handled by larger retreaders, those who may have more
sophistication than some of the smaller shops. Also the
shortage of suitable passenger tires available for retreading
may lead to relaxation of standards.
Retreaders in general try to retread only the best grade of
tires, eliminating the lower cost, lower quality, lines of new
tires. Testing of the better grades also eliminates many tires
as unsuitable for retreading due to damaged carcasses, etc.
The approximate 20% level of retreaded tires from all new
tires manufactured leads one to believe that this level may
not be easily exceeded, because of excessive carcass abuse
in normal service. Retreading can only replace tread wear
and cannot correct other damage.
Most competition comes from 3rd and 4th line new tires
specifically designed to compete in the "retread" cost
market. These tires, carrying the name brand of a national
company are backed by national advertising and distribu -
tion. The small retreader competes against these with a
brand-less tire. There is some "name" retread competition
by national tire companies, selling retreads on their own
brand carcasses.
A more complete review of the myriad of problems is
available in the literature^). The major problems are
inherent in the complexity of tire sizes, tread widths, etc.,
and the variable expansion of the tire carcass during its
original use. This forces the good retreader to measure each
tire, maintain a large inventory of molds, juggle his
inventory to maintain balance of salable sizes etc. Any
future tire quality specifications may also complicate the
retread industry.
All of these factors have tended to increase the cost of
retreading whereas the selling price has not increased
proportionally thereby putting the squeeze on the industry
profits. There is some feeling in the industry that this profit
squeeze may have led in some instances to lowering of
quality. If there is any basis in this viewpoint, it can only
lead to reinforcing the "second class" status of the entire
industry.
Some representatives of the industry believe that reason -
able, workable standards for the industry could lead to
increased usage of retreads by improved quality, and better
acceptance by the public through improved reliability.
Unworkable standards may conversely seriously restrict the
largest single converter of tire waste.
(^Braner, H.H., An Analyses of the Domestic Retreading
Industry, Ranno Printing Co., Englewood, N.J., 1965
67
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180 -
160 -
Total New Passenger f
i
i
140 -
120 •
100 -
800
60
40
20
S /
1940
1945
1950
1955
1960
1965
FIGURE 11-10 DOMESTIC PASSENGER TIRE SHIPMENTS AND RETREADS
(MILLION UNITS)
68
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30
28
26
24
22
20
18
16-1
14
12
10-
8
6
4-
2-
t «• — •
TOTAL NEW TRUCK TIRES
v/
xs /
RETREAD
1940
1945
1950
1955
1960
1965
FIGURE 11-11 DOMESTIC TRUCK TIRE SHIPMENTS AND RETREADS
(MILLION UNITS)
69
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o
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HISTORY OF TIRE SPLITTER INDUSTRY
Around 1915 when tires became available in large quanti -
ties, the forerunners of tire splitters called tire pullers came
into being. The industry consisted of pulling the cotton
fabric off old tires, thus separating certain plies of fabric
from each other and from the tread and sidewall. The bead
was first removed to make the carcass flexible. Bead
removal was first done by hand and later by machine.
John Ball discusses the operation in his book "Reclaimed
Rubber, The Story of An American Raw Material." R.R.A.
New York 1947. "The pulling of tires was first done by
hand, then with a pulley attachment, and later by a simple
motor driven machine. The elementary methods were quite
satisfactory as long as the fabric used in tires was square
woven duck, which has good strength and cohesion in any
direction to withstand the sudden pull or jerk." The
introduction of Weftless Cord in tires instead of square
woven duck made it very difficult to separate plies and tire
splitting instead of tire pulling came into being around
1925 when machines used to split hides and leather in
tanneries were employed to split tires. During the war
years, the prices of blowout patches and reliners, both
typical products of tire splitters became very high. As a
result, tire splitting became a very big business and in the
summer of 1945 over 125 splitters were in operation. They
accounted for about 1/3 of all the tire scrap received by the
reclaimers.
TIRE SPLITTER INDUSTRY
A portion of the nation's waste rubber is consumed by the
tire splitting industry. These little known companies use
worn-out bus, truck, and passenger tires. The bead wire is
removed by cutting or stamping; the tread is cut and peeled
off the tire carcass and the remaining carcass is slit into
three sections, the crown or tread and the two sides. These
carcass sections are now planed to uniform thickness and
placed in a press which die cuts out the final product.
Typical products are gaskets, shims, automotive tail pipe
insulators, and the familiar door mats. Circular and square
pieces are also stamped out and bolted or pinned together
to form items such as conveyor rollers for handling
produce, light load V-belts, and bumpers for docks and
loading platforms. Today there are three tire splitters in
business (Note 1.) Each, however, has an optimistic view of
his market and production and sales increases of 10 to 30%
are expected.
A total of 239 people are employed in the tire splitting
industry, 29 of which are salary and 210 are wage. All of
these companies are located within communities of
100,000 population or more. During the year 1968,
splitters consumed 39 million pounds of passenger tires and
15 million pounds of truck and bus tires, are normally
accumulated within a 100 to 200 miles radius from their
production facilities. The cost, up to SIS/ton-delivered, is
somewhat higher than the average cost of scrap tires to
conventional reclaimers.
Note 1
1. A. Lakin & Sons, Inc.
2. A. Schulman, Inc.
3. A. Baker Manufacturing Co.
Chicago
E. St. Louis, 111.
South Bend, Ind.
SOLID WASTE & BY PRODUCTS FROM INDUSTRY
Of the 57.5 million pounds of scrap tires consumed by the
industry, 14 million pounds were converted into finished
product (25%). The remainder was converted into 36
million pounds (63%) of useable by-product which was sold
to reclaimers. The remaining 7 million pounds (12%) was
returned solid waste. (TABLE II-13) In addition to the 7
million pounds of rubber waste not used, the industry
created three and one-half million pounds of new waste.
(TABLE II-14)
TABLE II-13
TIRE SPLITTERS-MATERIAL BALANCE (in 1000 pounds)
PRODUCTS
Split Tire Products
By Products-To Reclaimers
Tread peels (a)
Carcass Selvage (b)
SOLID PROCESS WASTE
Bead Wire (c)
Tires Unsuitable For Splitting (d)
GRAND TOTAL TIRES PROCESSED
(a) Tread portion of tires which is peeled off.
13,980
8,200
27,892
36,092
4,480
2,980
57,532
(b) Remainder of tire carcass after parts are die cut out.
(c) Bead wire portion of tires including rubber and
fabric covering which is cut from tire. Also includes
660,000 pounds of process waste, selvage, which is lost as
floor sweepings. This is disposed of with normal trash.
(d) Unused tires which are sorted from purchased scrap
tires as not being worthy of splitting, mainly studded
winter tires, steel re-inforced tires, and tires too small to
process.
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TABLE II-14
TIRE SPLITTING INDUSTRY WASTE
(in 1000 pounds)
SOLID PROCESS WASTE WEIGHT
Unuseable Tires 2,980
Bead Wire & Bead Rubber 3,820
Process waste, selvage, sweeping 660
Sub-total 7,460
OTHER SOLID WASTE
Packaging Materials 1,660
Other Categories 1,920
Sub-total 3,580
Grand Total 11,040
The overall industry material balance then becomes The overall reduction in total waste accomplished by the
industry is 46,492,000 Ibs. By-products sold to the re -
claimers, however, may create additional waste to those
57,532,000 Ibs. scrap tires accumulated industries, particularly in the testile portion of carcass
13,980,000 Ibs. of parts produced and sold selvage. The 11 million pounds of industry waste are
36,092,000 Ibs. of by-products sold mainly to reclaimers disposed of in sanitary land fills at a cost of 0.4 to 0.9 cents
7,460,000 Ibs. of scrap tire waste dumped per pound. One company uses its own trucks and labor for
3,580,000 Ibs. of new waste dumped dumping.
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SOLID WASTE RUBBER MANAGEMENT PROGRAM
The data of this report suggests the possibility of classifying
the entire waste rubber program into 3 broad areas:
a. Waste from the Rubber Industry
b. Automotive Rubber Waste
c. Consumer Rubber Waste
The Rubber Industry, as in any cost conscious industry,
makes every effort to effectively reduce cost through
reduction in waste product and re-use where possible. Some
types of waste are kept segregated and sold to other
processors for reuse such as the reclaimers. The second
classification, that of Automotive Waste Rubber, is more
easily segregated and accumulated after use than Consumer
Waste. In addition a system already exists for the collection
and utilization of this type. Consumer Rubber Waste is
undoubtedly the most difficult to categorize due to the
multiplicity of products and non-existence of segregation
and collection facilities. While many of these consumer
rubber products are reused in the reclaim industry when
available as rubber industry waste, it is apparent that
mixtures of these products are not easily nor economically
reclaimed in any conventional manner. Any re-use of this
vast mixture will undoubtedly be based on new techniques
for new products. It is then recommended that the latter 2
divisions be reviewed with regard to:
a) Collection
b) Shipping
c) Storage
d) Potential Reuse
e) Ultimate Disposal
COLLECTION
The present method of collecting automotive rubber waste,
predominantly tires, as outlined in Section I, could serve as
a nucleus for further expansion. The method which
accounts for approximately 30% collection of old tires for
use in the 3 major reuse industries, should not require
considerable revision to account for higher collection
percentages. Scrap merchants presently gear their collection
to reuse industry demand with the demand being filled
from nearby areas to minimize shipping costs. Since
collection is the reverse logistics of rubber products
distribution, a procedure developed to minimize costs, a
detailed study of this distribution may lead to more
economical collection methods. It has been suggested that
convenient and suitable collection sites would be
automotive service stations and tire sales stores.
Other suggested collection sites are municipal disposal areas
and unused armed forces areas.
Rubber waste such as tires, innertubes, and auto mats
would account for approximately 68% of the rubber goods
produced annually. To be accumulated automatically at
these points, an economic incentive for this type of
collection would have to be created by either new uses for
these wastes which would cover the collection costs or an
incentive to the consumer which would insure his turning
the waste in, such as a deposit paid on the new article
refundable upon turn-in. The latter does not appear
practical as the collection sites could be overwhelmed by
these worn out articles and it does not provide an incentive
to the site operator. On the contrary, it requires him to
maintain a costly collection and storage area.
Another plan might be a statutory surcharge on the original
commodity selling price to pay for later public collection
and disposal costs. This should be studied very carefully as
it not only creates an additional tax on the consumer but
may also be misinterpreted as license for casual discarding
of the article. No convenient method of collecting the
remaining rubber waste has been suggested by this report
and it is recommended this be a separate study. It is
possible that the inclusion of this waste in municipal waste
that is to be incinerated may be helpful to the incineration,
providing a readily combustible material to overcome some
of the less combustible wastes. This being particularly true
when wet wastes are to be incinerated.
SHIPPING AND STORAGE
If automotive tires are considered indicative of rubber
waste, considerable economies could result if they are
crushed or chopped as locally as possible prior to shipment
to use points. The average tire occupies 1.3 cubic feet of
space but when chopped, only occupies 0.5 cubic feet.
More weight may be shipped per vehicle load or stored in
any storage area by a factor of approximately 2% to 1.
The recommended waste chopping may be done in station -
ary choppers in high waste areas or on portable choppers,
moved on schedule, to low waste areas which cannot justify
permanent installations. It has been estimated that the cost
of a portable chopper would be $100,000. (TABLE 11-15)
TABLE 11-15
ESTIMATED COST OF PORTABLE
RUBBER WASTE CHOPPER
1.
2.
3.
4.
5.
6.
Flatbed tractor trailer
Alligator shears
Hammer mill — hogger
Screener
Fiber separator/magnets
Miscellaneous items
Total (1968 prices)
$40,000
5,000
30,000
5,000
15,000
5,000
$100,000
Testing of this type portable chopper in both high and low
waste areas could achieve significant results, with the
chopped waste also being evaluated locally as land fill or
incineration fuel (see Potential Uses). It should also be
noted that the design of either the stationary or portable
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chopper may be such as to prove of value in shredding
other types of waste such as glass, wood, paper etc. so as to
facilitate disposal or reuse. This should be an area of
additional investigation.
One serious drawback to public transportation of ground or
chopped rubber waste is the Interstate Commerce Commis -
sion designation of this type material. This regulation*
prohibits the bulk transportation of ground rubber waste
under certain conditions. This may restrict shipments in
bulk via public carriers, handling and packing costs.
*49CFR170:15
49 CFR 173:22
Para 73.201
POTENTIAL REUSE WITH REPROCESSING
The largest potential outlet for scrap rubber is rubberized
asphalt roads. This is a matter for serious study and all
possible assistance should be given to this program. The use
of rubber in roads was thought of, patented and tried well
over 130 years ago. However, it was not until the 1920's
that a serious set of laydowns took place in England on the
Dartford-Gravesend Road, London, and Lombard St.,
Birmingham. In these trials, rubber was added to a pitch
coated concrete road and rubber blocks served as the road
itself. In the U.S. in 1925, Goodyear tried laying a road
using solid rubber blocks but it was far too expensive and
very slippery when wet. In the 1930's in Europe and
England, the many institutes, laboratories and local rubber
interests investigated the use of natural rubber, which was
at a very low price, and of nitrile rubber. Many roads were
laid and the most notable was the Bussum road in Holland
laid in 1936 using rubberized asphalt which lasted through
World War II even under heavy war-time tank traffic. The
road laid in New Cross, London, by Dussek lasted into the
1960's. Much of the work which has been done in the past
has been less than definitive and much has been based on
the addition of new rubber or rubber latices, which may be
useful but irrelevant to the problem of solid waste disposal.
Some success was achieved in the work done prior to 1950
but the whole approach was empirical; there being no
thorough understanding of how the rubber acted in
modifying the properties of bituminous mixtures. From
about 1950 onwards research was intensified. Many full
scale experimental rubberized road surfaces were laid and
from these trials many specifications were published by
1964. The specifications basically are for topping a road
bed including recommended temperature ranges, aggregate
and bituminum (asphalt) proportions and method of
blending the recipe. In the English and European writings
mention is often made on the use of latex, vulcanized and
unvulcanized rubbers. A survey of selected articles on use
of rubber in asphalt, indicates a high degree of potential for
rubber scrap. However, there is no indication that raw
ground waste could be used to enhance the road properties.
Some degree of solubility is required and is not obtainable
unless the rubber molecular weight is substantially reduced
with a combination of heat, time and chemicals. Some of
the properties inherent in scrap may be desirable in rubber
for asphalt since it has been compounded, vulcanized to
higher molecular weight, and has some residual antioxidant.
It is estimated that at a 5% usage of rubber in all new
asphalt paving, the national demand would be equivalent to
the current generation of scrap rubber as tires. Studies in
this important potential usage, restricted to ground cured
rubber or reclaimed rubber, should incornorate:
a. Feasibility studies on the incorporation of rubber
material in asphalts and in hot or cold mix plants.
b. Determination of optimum levels of rubber addition.
c. Initiation of long term studies of the service
improvement value, if any, of such additions to pavings in
actual installations.
d. The logistics of supplying the waste in usable form
where needed. Grinding of waste at regional or local
disposal sites may be beneficial.
e. The extension of the use of cured scrap or reclaimed
rubber in asphalt to public play grounds, tracks, courts,
parking areas, and curbing or other barriers.
f. Determination of the degree and means of subsidiza -
tion required to ensure use of waste rubber in paving
asphalts, or, alternatively the proper form of mandatory
federal or state action to accomplish this purpose.
To date, the testing of waste rubber in roads has been
mainly done by dealers in the commodity. While liaison has
been established, between interested parties, a strictly
organized program should be created and explored. Al -
though a blanket endorsement cannot as yet be given, the
following advantages have been noted several times by
different laboratories giving justification for establishing
and supporting this program. Rubber modifies the behavior
of asphaltic binders in a number of ways: 1) The softening
point is raised which results in less flow at high road
temperatures; 2) the brittle point is lowered and therefore
less cracking results at low temperatures; 3) elastic proper -
ties are imparted to the asphalt. Road trials have shown the
advantages obtained from using a rubberized asphalt in
diffeient types of surfacing. In surface dressing, for
example, normal asphalt binders tend to "fat-up" under
heavy traffic at high temperatures. The addition of rubber
prevents this because of the reduced temperature suscepti -
bility of the binder. Also, the rubberized binder holds the
stones more tenaciously, resulting in a greater stone
coverage. When mixed materials are used, one of the most
important results obtained by adding rubber is the resis -
tance to cracking. This is particularly evident when the
surfacing is used on a weak base, or over concrete, when
cracks occur over the joints due to the movement of
adjoining slabs.
Aside from the use of rubber in roads, the following areas
show promise as large outlets for waste rubber. Reservoir
linings made of reclaimed rubber sheets retain water much
like the plastic sheeting now being used. Jetty and sea wall
coating, a blend of asphalt and reclaimed rubber may help
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to lower maintenance costs on these constructions. They
may also help to check soil erosion. The same blend can be
used in place of reclaim rubber sheets in reservoir linings,
culverts, and drainage ditches. Rubber and asphalt with and
without scrap tire fiber can also be used for roofing and
siding applications. Fiber, the by-product from the fiber
separation system of the reclaimers, can be used as
insulation board for buildings and truck bodies, mulch for
new grass plantings along highways, polymer recovery, fuel
for incinerators, filler for adding to concrete foundation
and roads, and as a low cost construction material when
coated with asphalt. Worn tires, reclaimed rubber slabs or
molded reclaim rubber can be used as highway guard rails
and impact absorbers and crumb rubber can be used as the
cushioning media.
The pyrolysis or destructive distillation of rubber has been
successfully accomplished resulting in products ranging
from fuel gas to oils to tars. A preliminary review of these.
products suggest no present economic capability to com -
pete with new products. Use of this distillate in competi -
tion with presently used oils for extending various new
rubbers would necessitate a low cost of the magnitude of
2-3 cents per pound.
The possibility of the distillate being used as a starting
material for synthesis in the chemical industry, is compli -
cated by the multiplicity of products or components
obtained with pyrolysis. It may be possible to exert more
control over the formation of these products through the
use of selected catalysts. However these catalysts will have
to exhibit broad activity in order to function with the
multiplicity of rubber types in service; including all the
added chemicals, curing agents and oils.
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Since nearly 41% of the solid rubber waste consists of
worn-out tires, solution of this segment of the problem will
greatly alleviate the overall disposal situation. The direc -
tions that further work on this part of the solid waste
problem should take are incorporated in the recommenda -
tions below.
1. The logistics of rubber scrap collection with emphasis
on scrap tires is the first essential. Tires are so widely
distributed, so obvious, and so large in annual volume that
the primary need is to gather them in sufficient concentra -
tion that economical facilities may be constructed for their
management and to ensure that they substantially disappear
from the general environment. Probably the best way of
studying the logistics of collection would be through a
study on the logistics of original distribution in cooperation
with the tire industry. The tire manufacturers and distri -
butors devised a system for getting tires to the point of use
at a minimum cost within a profit oriented structure. There
will be much to learn here as to the best system to use to
return the scattered scrap tires to new points of concentra -
tion. Perhaps the identical or closely similar chain of
operation could be used in reverse at minimum cost. That is
retailer, jobber, distributor, and warehouses
The logistics almost certainly require a local collection
system, reduction of bulk by chopping, establishment of
fair minimum rail and truck tariffs and regulations for
transportation to collection centers and establishment of
proper facilities at those centers.
2. Facilities need to be developed for efficient and con -
trolled conversion of rubber waste. As with any waste, no
conversion system can make rubber solid waste disappear
but can only convert it to a less objectionable or possibly
useful form. Proper and practical performance standards on
any disposal method must be established promptly, on an
interim basis if necessary, so that obsolescence by statutory
action will not further complicate the problem. Incinera -
tion appears to offer the best present conversion method as
it can result in major reduction of solid waste with the
potential production of heat, steam and possibly power. It
also has the vast technology of furnace and boiler design as
a starting point. The high heat of combustion, the
generation of noxious sulfur, nitrogen, and other gases, and
the relatively high content of metal and ash will make this a
difficult design problem which probably will require fi -
nancial support at the beginning.
3. Other conversion means have been suggested such as the
pyrolysis work of the Bureau of Mines with the Firestone
Tire and Rubber Co. or chemical or biochemical processes.
These do not offer as quick or as economically feasible
solutions in the short run but they appear to be deserving
of continuing supported research. Centralized facilities for
collection and combustion of scrap would offer ideal
support for pilot operations of advanced conversion studies.
4. Densification of tires and other rubber waste is essential
whether they are to be disposed of in local land fill, burned
in local incinerators, or shipped to centralized collection
centers. This densification requires only cutting and chop -
ping to less than one inch size and can be done with
existing unit equipment. Supported efforts should be
directed to the design of pilot systems, preferably portable,
which will do this size reduction cheaply, with minimum
investment, minimum labor input, and sufficiently rugged
to operate outdoors in rugged terrain and with little or no
special maintenance.
5. Waste rubber in roads is a matter which calls for serious
study. Much of the work which has been done in the past
has^-been less than definitive and much has been based on
the addition of new rubber or rubber latices, which may be
useful but is irrelevant to the problem of solid waste
disposal. It is estimated that at a 5% usage of rubber waste
in all new asphalt paving, the national demand would be
equivalent to the current generation of waste rubber tires.
Studies in this important potential usage, restricted to
ground cured rubber or reclaimed rubber, should incor -
porate:
a. Feasibility studies on the incorporation of rubber
materials in asphalts and in hot or cold mix plants.
b. Determination of optimum levels of waste rubber
addition.
c. Initiation of long term studies of the service
improvement value, if any, of such additions to pavings in
actual installations.
d. The logistics of supplying the waste rubber in usable
form where needed.
e. The extension of the use of cured waste or reclaimed
rubber in asphalt to public play grounds, tracks, courts,
parking areas, and curbing or other barriers.
6. The Bureau of Solid Waste Management could main -
tain continuing surveillance over federal, state, and local
legislation, industry standards, consumer demands, and
technological changes to ensure that such programs and
regulations do not inadvertently and unnecessarily exagger -
ate the scrap rubber problem by limiting the service life of
rubber products. This could comprise, among other things,
tire safety standards, retreading standards, highway speed
maximums, highway construction standards, axle-load
standards, tire overload standards for original equipment,
industrial safety standards involving belts, hose, cable and
personal protective equipment. Although such action for
the public is intended for beneficial purposes there is
always the possibility that through over-enthusiasm or lack
of information the actual service life of tires and other
rubber products may be reduced to the extent that the
solid waste problem is seriously aggravated. The Bureau of
Solids Waste Management should be prepared to advise on
such public actions before they are given final form.
7. Waste rubber, particularly tires, could possibly be used
as protective barriers on the nation's motorways. Either in
the form of whole tires or ground rubber in containers,
they could be effective impact absorbers at underpasses,
median barriers or land cuts.
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I
Adjusted Tires
Tires that have passed initial manufacturers inspection but are
revealed after use, to be unfit. They are returned to the dealer for
compensation.
Clean Outs
Residual rubber left in machinery from prior runs which is
removed and discarded.
Factory Wastes
Floor sweepings, polymer removed for testing and later discarded,
etc.
Innerliner
An integral inside tire layer for improved air retention.
Mechanical Products Scrap
Products rejected by producer as being unfit for use due to
manufacturing defects.
Nerve
A generic term used to denote the "springiness" of a polymer.
Usually used when referring to the uncompounded polymer.
Off-the-road-tires
Tires which are larger than normal bus and trailer truck tires such
as found on large earth moving equipment.
Other (as used in Table II-4)
Primarily selvage and portions of rubber polymer removed for
testing.
Peelings, Fabric Free
Strips of tread which have been peeled off worn tires.
Polymer
A chemical compound formed by combining small molecules or
atoms into long chains of essentially repeating structural units.
Raw Polymer
A polymer which has not been mixed with compounding
ingredients such as curing agents and softeners.
Rejected Tires
Tires rejected by a producer as being unfit for use due to
manufacturing defects.
Retread Buffings
The crumb rubber produced when a retreader grinds off the
remaining tread from a worn tire before applying a new tread.
Rubber
A general term for polymer compound, and products.
Rubber Compounds
As used in this report, rubber compound refers to the polymer
mixed with fillers, oils and curing agents.
Rubber Latex (latices)
A milky or tan colored solution consisting of rubber in water.
Safety Barriers
Separate liners placed inside tires to seal punctures and leaks
which occur during road use. The liner may be a contaminant of
reclaim or else it presents a manufacturing difficulty to the
industry.
Scrap
Manufactured rubber articles or parts rejected or discarded and
useful only as material for reprocessing.
Selvage
A border or edge trimmed off a molded part; also, that portion of
a sheet of rubber which remains after parts are die-cut out.
Square Woven Duck
Fabric consisting of threads woven perpendicularly i.e. equal
amounts of weft and warp.
Tire Parts
Tire selvage usually from the splitting industry.
Tire/Tire Products
Tires, innertubes, rubber curing bags and other products relating
to tires or their manufacture, renovation or repair.
Waste
Rubber articles which through wear or contamination are
disposed of as being of no further use.
Weftless Cord
A woven fabric in which the weft threads are replaced by a
limited number of very thin threads.
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This portion contains an alphabetical list of the oils and
chemicals used or investigated by the reclaiming industry.
Alongside each item, in italics, is the name of the person or
organization that published data pertaining to the item. The
periodical the data appears in will be listed under the
person's name in the second section.
Accelerators Khodevitch, L.
Acid, abietic Treves, A.
Acid, Aliphatic, unsaturated derivatives Tsvetaeva, EM.
Acid, benzoic Amphlett, P.H., Hughes, A.J., Twiss, D.F.
Acid, carboxylic Wingfoot Corp.
Acid, carboxylic, anhydrides Drozdovskii, V.F., et al
Acid, cresylic, petroleum, sulfide of Smith, G.E.P., Jr.
Acid, Dithiocarbamic (1) Cech, C.J., Bata, A. -G. (2) Regie
Nationale Des Usines Renault (3) Bata, A. -G. (4) Yaroslav,
C.
Acid, fatty (1) Lebeau, D.S. (2) Tsveteava, EM. (3)
Rein-Chemie G.m b.h.
Acid, formic Rubber Reclaiming Co.
Acid, Hydrochloric (1) Hudecek, J., Dlab, J. (2) Dasher,
P.J.
Acid, mineral (1) Pearson, W.L., Schweller, H.E. (2) Dasher,
P.J.
Acid, napthenic See Napthenic Acids
Acid, organic Kirby, W.G., Elliott, P.M.
Acid, organic, polyglycol esters of Saul, W., Wiggins, T.J.
Acid, organic, zinc or aluminum salt of Johnson, T.A.
Acid, Phosphoric Kelly, J.H., Jr.
Acid, Phospheric, alkyl salt Kelly, J.H., Jr.
Acid, Phosphoric, alkyl Kelly, J.H., Jr.
Acid, sulfuric, conc.Naftolen Gesellschaft
Acid, sulfuric, dil. Semperit Gummiwerk G.P.
Acid, sylvic Treves, A.
Acid, tar, by-pioductsMetallgesellschaft, A. -G.
Acid, thioglycoltic, B-napthalide of Drozdovskii, V.F.
Activator, surface Sanyou, Yushi Kogyo Co.
Activator, sulfur containing Drozdovskii, V.F.
Additives Dufour, R., Leduc
Agents, devulcanizing (list) Oil, Paint and Drug Reptr., 141:
p. 60 (May 25, 1942)
Agents, non-stain Keilen, J.J., Dougherty, W.K.
Agents, softening, soling waste Mishustin, I. U.
Agents, swellingRivier, A., Dietzel, E.
Agents, swelling, cracking aid Reich, H.F.H.
Agents, swelling, study Rostler, K.S., White, R.M.
Alcohols, aliphatic Sartorelli, U.
Alcohols, aliphatic, monhydric Wingfoot Corp.
Alcohol, ethyl Moore, D. V., Thompson, H.H.
Alcohol, n-butyl, w/steam Bergmann, F., Dishon, B.R.
Aldehyde Mankowich, I.
Alkali Levin, M.
Amide Kirby, W.G., Elliott, P.M.
Amine, aliphatic Smith, G.E.P., Jr., Bennett, R.B.
Amine, aliphatic, water insoluble Kelly, J.H., Jr.
Amine, alkylol Dasher, P.J.
Amine, hydroxyl— Dasher, P.J.
Amine, hydroxyl-, (or salt) Dasher, P.J.
Amine, mercapto— Dasher, P.J.
Amine, napthyl, phenyl-beta- Johnson, T.A., Thompson
H.H.
Amine, poly—, aliphatic Dasher, P.J.
Amine, secondary, polycyclicZ)efVae/e, A.
Amine, Tri-, diethylene VanValkenburgh, E.A.
Ammonia Joyce, W.T., Geyer, H.D.
Ammonia, emulsions, w/reclaim Radinger, EJ.
Anhydride, maleic Green, J.
Anisates Tsvetaeva, EM.
Aromatic, Hydrocarbons Lambrino, V., et al
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Asphalt, residue Kilbourne, F.L.
Bentonite Thompson, H.H.
Benzene, chloronitro- Schwerdetel, F.
Benzene, nitrochloro-/.G. Farbenindustrie
Bitumen (1) Ghez, H., Ghez, O. (2) Hermes Patentverwer -
tungs, G.mb.h. (3) Accumulatoren-Fabrik
Borate Flood, D. W.
Bromides, ihiosuifonyl Proell, W.A.
Carbazole, derivatives, sulfur containing Drozdovskii, V.F.,
etal
Carbon Black (all reclaim tread) Continental Carbon Co.
Carbon Black, (tread) Cohan, L.H., Mackey, J.F.
Carbonate, calcium Bulli, M.
Carbonate, sodium Bulli, M.
Catalysts Drozkovskii, V.F.
Catalyst, multivalent Staten, F. W., Haines, W.M., Jr.
Catalyst, plasticizing Baudelot, P.
Cellulose Kirby, W.G., Steinle, I.E.
Chloride, ammoniumKirby, W.G.
Chloride, di-, sulfur Smith, G.E.P., Jr., Ambelang, J.C.
Chloride, hydrogen Kobrinskii, L.S.
Chloride, hydrogen, anhydrous Midland Silicones Ltd.
Chloride, sulfonylBata, A. -G.
Chloride, sulfur (1) Cook, W.S. (2), Hensley, W.A.
Chloride, thiosulfonylProell, W.A.
Chloronitro, aromatic, compounds/.G. Farbenindustrie
Colophony Treves, A.
Copal Treves, A.
Cryptomeria Kawashima, Y.
Cyanates, thio-, organic Drozdovskii, V.F., et al
Cyclopentadiene Boyd, J.H.
Disulfide, aliphatic Elgin, J.G.
Bisulfide, Alkyl, cresnol Beloroxxova, A.G., Faberov, M.I.
Disulfide, alkyl, phenol Drozdovskii, V.F., et al
Disulfide, aromatic Schneider, P.
Disulfide, benzothiazoyl Yaroslav, C.
Disulfide, carbon Kawaoka, J.
Disulfide, diaryl-, w/nitrated groups/.G. Farbenindustrie
Disulfide, dibenzothiazoylBata, A. -G.
Disulfide, di-(trichlorophelyl).Z>ozdovsfc/z, V.F.
Disulfide, (effects) Dogadkin, B.A., et al
Disulfide, hydrocarbon Tewksbury, L.B., Jr., Howland,
L.H.
Disulfide, hydroxyarylKirby, W.G., Steinle, I.E.
Disulfide, organic Warren, S.F.
Disulfide, Tert-butyl cresol Beloroxxova, A.G., Farberov,
M.I.
Disulfide, Thiazoyl Yaroslav, C.
Dye, azo (non-stain) Phoenix Gummiwerk A. -G.
Ester, acrylic Dasher, P.J.
Esters, w/OH groups Continental Gummiwerk
Ether, dibenzyl Satake, S., Tatebayashi, K.
FacticeMorche, K., Ehrend, H.
Fat, woolRenneman, H., Gunzert, T.
Fillers Dufour, R., Leduc
Formaldehyde Mankowich, I.
Furfural Sakada, M.
Gas, exhaust Johnson, A.
Gas, tars Krivunchenko, N.G., et al
Glycerin Rebmann, A.
Glycol, ethylene Continental Gummiwerk
Glycol, ethylene Johnson, T.A., Thompson, H.H.
HeptenesElgin, J.G., Sverdrup, E.F.
Hexane Tsveteava, EM.
Hexanol, polyalkylcyclo- Cook, W.S.
Hexenes Elgin, J.G., Sverdrup, E.F.
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Hydrazine, monoacrylo-/.G. Farbenindustrie
Hydrazine, monoaryl- (1) Gumlich, W. (2) I.G. Farbenin -
dustrie (3) Bachle, O.
Hydrides, metalloid (butyl) Baldwin, P.P.
Hydrocarbons, aromatic, OxidisedLorand, E.J.
Hydroxide, sodiumNeal, A.M., Schaeffer, J.R.
Irradiation, radioactive Drozdovskii, V.F., et al
Kerosine Al'tzitser, V.S., Tugov, I.I.
Lampblack Dubrovin, G.I.
Material, surface-active Bruckner, Z., Juhasz, M.
Metal, heavy, salts ofRein-Chemi G.mb.h.
Metal, molten, alloy bathKelefti, Z.
Mercaptans, (effects) Dogadkin, B.A., et al
Mercaptans, aliphatic Elgin, J.G.
Mercaptans, aromatic (1) Ecker, R., Gumlich, W. (2)
Schneider, P. (3) I.G. Farbenindustrie
Mercaptans, aromatic, w/ammonia salts-amine salts of acids
Bahr, K., Schmidt, K.
Mercaptan, benzyl Mersereau, J.M., Mester, P.J.
Mercaptan, tertiary lauryl Warren, S.F.
Meicaptoamine Dasher, P.J.
Naptha Corkery, F. W.
Naptha, extraction of isobutylene with Sparks, W.J.,
Baldeshwieler, E.L.
Naptha, solvent LeBeau, D.S.
Napthalene Studio Chemico Industriale
Napthalene, tetrahydro Renneman, H., Gunzert, T.
Napthenates,4wp/)/err, P.M., Hughes, A.T., Twiss, D.
Napthenic, hydrocarbons Lambrino, V., et al
Napthols, dialkyl-Hensley, W.A.
Nitrite, sodium LeBeau, D.S.
Octanes Elgin, J.G., Sverdrup, E.F.
Oils (list) Oil, Paint and Drug Reptr., 142: no. 15, p. 44.
(October 12, 1942)
Oil Deutsche, Shell A. -G Metallgeselhhaft A. -G.
Oil, anthracene Spocete, A.
Oil, arabic, lubricating Asano, T., Kusunoski, S.
Oil, aromatic, w/naptha Corkery, F. W.
Oil, fish Endo,H.
Oil, hemp seed Syui-Chzhou, Li.
Oil, mineral, oxidized Polyplast Gesellschaft Fur Kautschu -
kchemie
Oil, napthenic Nicolaisen, B.H.
Oil, paraffin Oblocynzsky, J.
Oil, reclaiming (1) Beaven, E.W.J. (2) Beverly, J.A. (3)
Campbell, C.H., Ostermayer, R.W. (4) Van Valkenburgh,
E.A.
Oil, resin, grey tower Randall, R.L.
Oil, resin, reclaiming Campbell, C.H.
Oil, Rosin, (non-stain) Brown, G.L., Johnson, T.A., Knill,
R.B.
Oil, Schist, w/NRBechtold, H.A.
Oil, shale Tsveteava, EM.
Oil, soybean Sugimoto, S., Minamikata, /., Sakai, K.
Oil, sulfur, mix Clayton, R.E.
Oil, Tall Van Valkenburgh, E.A.
Oil, tall Zachesova, G.N., et al
Oil, tall, oxidized White, CM.
Oil, tall, sulfurized Nicolaisen, B.H.
Oil, tar, solvent Osipovsky, B. Y., et al
Oil, vegetable Endo, H.
Olarrune, alkyl- Clarke, R.B.F.E.
Oleate, triethylamine Polyplast Gesellschaft Fur Kautschu -
kchemie
Olefin, copolymers Montecatini, Soc. Gen.
Oxidants Zaionchkovskii, A.D., et al
Oxygen (1) Bennett, R.B., Smith, G.E.P. (2) Essex, W.G.
(3) Gibbons, P.A.
85
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Oxygenic, pto-Haehle, A.
Paraffins Campbell, A. W.
Paraffinic,hydrocarbons/,am6n'«o, V., et al
Peptizer (1) Castello, A.D. (2) Drozdovskii, V.F., et al
Peroxide, hydrogen Amphlett, P.H., Hughes, A.J., Twiss,
D.F.
Peroxide, Hydro-, a,a-di-alkylarylmethylZ-ewK, J.R.
Peroxides, Organic Continental Gummi Werk
Phenol Smith, G.E.P., Jr., Ambelang, J.C.
Phenol, thio (1) Drozdovskii, V.F., et al (2) Garvey, B.S.
(3) Ned, AM., Schaeffer, J.R. (4)Rebmann, A.
Phenol, trichloro- Vinitskii, L.E., Litovchenko, M.P.
Phenol, trichlorothio- (1) Drozdovskii, V.F., et al (2)
Shokin, LA.
Phenol, trichlorothio-, disulfide of Drozdovskii, V.F., et al
Phenol, trichlorothio-, zinc salt of Drozdovskii, V.F., et al
Phosphates, alkyl Kelly, J.H., Jr.
Phosphine, triphenyl- Drozdovskii, V.F.
Pigments Westhead, J.
Plasticizers Ceva, A., Trius, V.
Polymer, high styrene, reclaiming in presence of Sverdrup,
E.F.
Products, petroleum for rubber Standard Oil Co.
Propane Tsveteava, E.M.
Propylene, poly-, atactic White, R.A.
Reagents (list) Oil, Paint and Drug Reptr., 142: No. 3, p. 44
(July 20, 1942)
Reclaiming Agents (synthetic rubber) Cook, W.S., Albert,
H.E., Kilbome, F.L., Smith, G.E.P.
Reclaim, non-stain, w/soap Castello, A.D., Dixon, H.L.
Resins Patel, M.U.
Resin, Coumarone (1) Kenneman, H., Gunzert, T. (2)
Spocete, A. (3) Treves, A.
Resin, gas generating Krivunchenko, N.G., et al
Resin, Phenol, formaldehyde (1) Dinzburg, D.N. (2) Haang,
C. Y., Tanabe, H.
Resin, pine Syui-Chzhou, Li
Resin, pine, wood (1) Naudain, E.A., Bays, CM. (2) Ray,
P.A.
Resin, pine, tar Tsi-Te, Ku.
Rosin Zachesova, G.N., et al
Rosin, pine Liverovskii, A.A., et al
Rhodanides, alkali Ecker, R., Bahr, K.
Selenide, aryl Wheeler, G.P.
Sensitizers, heat Campbell, A. W.
Shale Tsveteava, E.M.
Siloxanes, diorganopoly-, acyloxy end blocked Bruner, L.B.
Softeners (1) Nikolaev, N.V., et al (2) Sugino, K. (3)
Tsveteava, E.M.
Solvent Jaeger, R. W.
Solvent, naptha Kilboume, F.L.
Spirit, white Al'tzitser, V.S., Tugov, I.I.
Sulfides, aromatic, armine, NJSf-Dialkyl Albert, H.E.,
Ambelang, J.C.
Sulfide, arylamide Webb, E.J., et al
Sulfide, dicresol Albert, H.E.
Sulfide, dixylyl Higgins, C.J., Forman, D.B.
Sulfide, mono-, Bis(tetraalkylphenol) Cook, W.S., Smith,
G.E.P.,Jr.
Sulfide, tetraalkylphenol Cook, W.S., Smith, G.E.P., Jr.
Sulfide, thiazylBata, A.G.
Sulfide, Thiuram (1) Bata, A.G. (2) Yaroslav, C.
Sulfide, zinc Stafford, W.E., et al
Sulfite, pulp Sarada, M.
Sulfoxide, bis, phenol Cook, W.S.
Sulfoxide, bis (4,6-di-tert-butyl-3-methylphenol) Cook,
W.S.
Sugar Kirby, W.G., Steinle, I.E.
86
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Swellers (list) Oil, Paint and Drug Reptr., 142: No. 16, p.
71, (October 19, 1942)
Tarr, coal Spocete, A.
Tar, coal, distillate Wingfoot Corp.
Tars, gasKrivunchenko, N.G., et al
Tar, lignite Kuznetson, V.I., et al
Tar, pine (1) Amphlett, P.H., Hughes, A.J., Twiss, D.F. (2)
Berryman, G.C. (3)Solokov, S.A., et al
Thiazole (1) Bata, A.G. (2) Cech, C.J., Bata, A.G. (3)
Yaroslav, C.
Thiazole, mercaptobenzo- (1) Amphlett, P.H., Hughes, A.J.,
Twiss, D.F. (2) Kawaoka, Y.
Thiol, aromatic Gumlich, W., Ecker, R.
Thiophene (ring) Sverdnip, E.F.
Toluene, ihiophene Kimishima, T.
Urea, phenylthio Kawaoka, Y.
Utanol See Utanol
Application and Uses of Reclaimed Rubber
Adinoff, S. Manufacture and properties of rubber adhesives.
R.A. (N.Y.), 49: pp. 171-72, 204 (June 1941). Natural and
reclaimed rubber cements.
Anon. Using old rub. stocks Vol. 143 No. 10 page 362 yr
62 Ln. 2 Rub PI Wk
Bobyl'knov, M.I., Tabachnik, E.I., and Shevyreva, L.P.
Reclaiming and Manufacture of Brake Linings from Scrap
and Worn-Out Linings. Kauchuk i Rezina, No. 5, pp. 67-71
(1938). (21 lines in C.A., 32:7605; S.C.L. 16:793).
Bowler, R.P. Disposable tire treads. U.S. Pat. 3,007,506
(Nov. 7,1961). (To J.P. Malone Co.)
Busenberg, E.B. Reclaimed rubber in tires and other
transportation items. (Abstract only). Rubber Age, 83: p.
854 (1958). (R.A., 36:526). The use of reclaimed rubber in
carcass compounds.
Carpmael, M.H. Recovery of rubber. Brit Pat. 602,725
(1948). (To Manufacture de Caoutchouc Michelin, Puiseux,
Boulanger et Cie). (S.C.L., 26:727). Ground scrap rubber
mixed with new rubber stock.
Cattania, U. Water impermeable sheets. Swiss Pat. 214,410
(C.A., 36:3340; S.C.L. 20:318). Consisting of reclaim and
bitumen.
C.K. Reclaimed rubber as a substitute for raw rubber. Tech.
Handel, 27: p. 199 (1937). (S.C.L., 16:45).
Crawford, R.A. Composition of matter. U.S. Pat. 2,265,770
(Dec. 9, 1941). (To Goodrich). Spongy, sound-deadening
composition comprising reclaimed rubber asphalt, wood
flour and rosin.
Demidov, G.K. Manufacture of roofing material and other
articles from scrap materials of tire production. Kauchuk i
Rezina 19 (4), 45-7 (1960); Soviet Rubber Technol 19 (4),
42-4 (1960) (R.A., 39:122).
DPR, Inc. Pourable rubber. Rubber World, 148: 7 (1963).
(R.A., 41: 405). A specially compounded depolymerized
rubber can be used to make poured-in-place gaskets for half
the cost of cut-out gum gaskets.
Earnest S.A. Hovland L. W. Minford J.D. Mach. Design, 39,
no. 2, Jan. 67, p 192 Adhesives for aluminum. Composi -
tions involving reclaim are discussed.
Ehrend, H. Use of special reclaim in SBR stocks. Gummi,
Asbest, Kunststoffe 15 (9), 818,822,824-9 (1962). (R.A.,
40:580).
Ehrend, H. Use of Reclaim in cpds Gum Asbest Vol. 15 No.
9, Page 818, Yr. 62 Ln 12.
Engelbach, T.J. Solid Composite propellants prepared from
depolymerized rubber. U.S. Pat. 2,953,446 (Sept. 20,
1960), (C.A., 55:2108; R.A., 39; 195).
Esman, P. I. Use of reclaim. Kauchuk i Rezina, 18: No. 2,
pp. 54-55 (1959); trans, in Soviet Rubber Tech., 18: No. 2,
p. 56 1959. (R.A., 37:428). Conveyor belts.
Fischer, R. Utilization of used rubber. German Pat.
854,258 (Aug. 28,1952). (R.A., 31:309).
Garner, T.L. Use of Reclaimed and Waste Rubber in
Rubber Compounding. Chem. Age, 41: pp. 22-23 (1939).
(S.C.L., 17:547).
Garvick, K.R. Reclaimed rubber in pneumatic tires and
tubes. Rubber Age N.Y. 89 (2), 304 (1961). (R.A.,
39:391). A review.
Gryzlova T.A. Sinyaev V.P. Izv. Vyssh. Uchebn Zaved
Tecknol no. 5 1965 p 33. Investigations into the use of
reclaim on the formulations for feathery and light porous
sole vulcanizates.
Hardman, K.V. and Lang, A.J. Properties, uses and com -
pounding of depolymerized rubber. Wire Prod. 1962 (Apr).
484-90. (R.A., 40:446). Applications to the electrical trade.
Hess, E.F. Honeycomb adhesives Vol. 18 No. 2 Page 12 yr
60 Ln. 4 Plas World
87
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Heyman, J. Reclaiming of vulcanized rubber scrap. French
Pat. 1,015,924 (Oct. 28, 1952). (R.A., 31:217; Rev. Gen.
Caout., 30:134). Powdered scrap is mixed with latex.
Hublin, R.A. Evaluation of Mixings Containing Reclaim.
Rev. Gen. Caout 16: pp. 297-302, 329-35 (Oct. and Nov.,
1939). (S.C.L., 18:32).
Imperial Chemical Industries, Ltd. Use of reclaimed rubber
for adhesive solutions and cements. (Technical Report).
(S.C.L., 20:282).
Jackson, B.S. Rubber J., 148, No. 9, Sept. 1966 p 46
Making use of rubberlike materials in building sealants.
Types, properties and test methods.
Katz, I. Gov. Specs-Adhesives Adhes. Age Vol. 8 No. 2 Page
24 Yr 65 Ln 8
Kujawa B. and Penczek A. Adhesive for Floor Covering
Based on Reclaimed Rubber Plasteau Kaut 12, no. 8, Aug.
65-p487.
Levitin, I. New Use For Reclaim Sov. Rub. T. Vol. 21 No.
HPage39Yr62Ln. 2.
Macy, J.H. Reuse of vulcanized scrap synthetic rubber. U.S.
Pat. 2,378,717 (June 19, 1945). (To Goodrich). (C.A.,
39:3966; S.C.L., 23:370). Grinding the scrap, mixing it
with an unvulcanized copolymer of 1,3-butadiene and
acrylonitile or styrene, and vulcanizing the mixture.
Manufacture de Caoutchouc Michelin (Puiseaux, Boulanger
et Cie). Rubber articles containing used rubber. Nether -
lands. Pat. 67,986 (May 16, 1951). (S.C.L., 29:661). Used
rubber in Polyhedral fragments.
Marr, R.B. Rubber in the paper industry. Pulp Paper Mag.
Can., 41: pp. 439-44 (June, 1940)
Midwest Rubber Reclaiming Co. Reclaim in a first quality
"cold" rubber tread-a road test. (Booklet) (C.A., 45:6422;
S.C.L., 28: 195).
Moncrieff, R.W. Plastics, 30 no. 336, Oct. 1965 p 79
Structural Reinforcement of polyurethane foams with
reclaimed scrap.
Mysona, M. Golebiowski, T. and Sliwa, T. Use of scrap
rubber as a filler for phenol-formaldehyde molding com -
pounds. Plaste Kautschuk, 11(8):479-80 (1964). (R.A.,
42:638).
Palmer, H.F. Use of reclaimed rubber in mechanical and
hard rubber goods. R.A. (N.Y.), 47: pp. 249-51 (July,
1940).
Peik, P.G. Sound deadener. U.S. Pats. 2,240,014 and
2,240,015 (Apr., 1941). Of rubber and reclaimed rubber.
Plumb, J.S. Use of reclaimed rubber in sponge rubber
goods. R.A. (N.Y.), 47: pp. 165-55 (June, 1940).
Preparation of Water Dispersions of Raw Rubber, Reclaim,
Substitutes, and Bituminous Substances. G.Z., 52: pp.
407-09, 430-31 (1938). (S.C.L., 16:501,694; B.C.A. (B),
696-1938).
Reclaimed rubber in code wire insulation stocks. Vanderbilt
News, 7: No. 4, pp. 16-17 (July-Aug., 1937).
Reclaimed rubber in friction and coat stocks. Vanderbilt
News, 7: No. 4 pp. 6-9 (July-Aug. 1937).
Reclaimed rubber in tire tread or belt cover stocks.
Vanderbilt News, 7: No. 4, pp. 10-11 (July-Aug., 1937).
Rubber Cement Products, Ltd., and Watts, RHP Plastics
compositions. Brit. Pat. 537,135 (June 10, 1941). (C.A.,
36:1807). Mixtures of compounded latex with Portland
cement, sand, and granulated cork, troweled out in sheets
of l/8th of an inch thickness and vulcanized.
Rubber Couplings in Swedish Railroads vol. 20, no. 2,
1967, p. 65 (NR)
Rubber Developments vol. 20, no. 1,1967, p 26 (14" x 4"
x 1 pads) (NR) Roadside Safety Fencing Shock Absorbers.
Rubber Developments vol. 19, no. 4, 1966, p 135 (sur -
facing method) (NR) Natural Rubber for Severn Bridge
Surfacing.
Rubber Developments vol. 20, no. 2, 1967, p. 61 (850
Ibs/units) (NR) Marine Dock Fenders.
Rubtex Rubber Products. R.A. (N.Y.). 42: p.318 (Feb.
1938). (S.C.L., 16:764). See Also: A New Method of
Utilizing Reclaimed Rubber (Rubtex) in Rev. Gen. Caout.,
15: No. 138, p. 24 (Jan., 1938).
Shanker, U. Liquid rubber. Rubber News 1 (3), 29-30
(1961). R.A. 40:446)
Shokhin, I. and Smirnov. A. Structural material from scrap
rubber Stroital. Materialy, 2: No. 10, pp. 9-11 (1956).
(C.A., 51: 10110;R.A., 35:521). Asbestos-ebonite tiles.
Snell, F.D., Inc. Use of depolymerized rubber. I.R.W., 122:
p. 69 (1950), (S.C.L., 28;523). As a plasticizer for natural
rubber.
Sumkin, V. Reclaimed rubber containing lead oxide from
rubber used for x-ray rubber goods. J. Rub. Ind. (U.S.S.R.),
12:1059-60 (1935). (C.A., 30:6603).
Testworth Laboratories. Reclaim rubber compounds as
substitutes for latex. Chem. Eng. News 21: p. 692 (May 10,
1943). Including a specially formulated compound of
reclaim rubber emulsion which saved 40% of the reclaim by
substitution.
Thoillet, R., and Haehl, A. Designing compounds based on
reclaim. Rev. Gen. Caout., 18: pp. 163-70 (1941). (S.C.L.,
20:185;Chem. Zentr., 113: Pt.I:546).
88
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Trivedi, N.N. Rubber Footwear I Vol. 19 No. 1 Page 23
Jan. 1967 Len. 7 Lang. Eng. Rubber India.
Twiss, S.B. Adhesive Use in Autos Adhes. Age. Vol. 6, No.
12, Page 16, Yr. 63 Ln. 7.
Uses of reclaimed rubber. I.R.J., 99:pp.57-58 (1940).
(S.C.L., 18:32) Brief review.
Westhead, J. and Bloxham, J.L. Applications of reclaimed
rubber. Rubber Plastics Weekly 140 (16), 607-8 (1961).
(R.A., 39:345). The advantages and disadvantages are
discussed.
Whelan, L.A. Field experiments on Dartonfield Estate.
XXIV. Maturing experiment with mature rubber (1943).
Rub. Res. Scheme Ceylon, Quarterly Circular, 21: pp. 6-8
(1944). (S.C.L., 23:250).
Whelan, L.A. and deSilva, C.A. Field experiments on
Dartonfield Estate. XXI. Manuring experiment with mature
rubber. XXI1. Growth of replanted areas. Rub. Res.
Scheme Ceylon, Quarterly Circular, 20: pp. 10-14 (1943).
Development of Reclaimed Rubber
Alexander, P. Methods of Reclaiming Rubber Employed
during the Past Hundred Years. "Proc. Rub. Tech. Conf.,
1938", pp. 516-24. Repr. in I.R.J., 96: pp. 780-83 (Dec.
31,1938). (S.C.L., 16:296).
Anon. Modern Reclaim Installations in the Rubber and
Plastics Industry. Gummi Asbest Kunstst 18, 5 May 65 p
552.
Ball, J.M. Recent rubber industry developments in re -
claimed rubber. I.R.W., 122: pp. 58-59 (1950). (C.A.,
44:5131 ;S.C.L., 28:562)
Chadwick J. the use of reclaim under modern conditions.
Proc. Inst. Rubber Incl. (42) p 15 (1966) General Discus -
sion See also IR News Vol. 5 8 p 28 May (1966)
Fritton, W.J. Recent advances in reclaimed rubber. Rubber
Age (N.Y.), 94 (2): 282-5 (1963). (R.A., 42:115). Ad -
vantages of reclaim are described.
LeBeau, D.S. Rubber Chem. Tech. 40, no. 1, Feb. 67 p
217-37. Science and Technology of Reclaimed Rubber,
Developments over past twenty years.
Pariente, C., and Rohrer, P. Recent reclaim progress. Bull
Tech. Perodique Franterre, No. 10: pp. 1-9 (1953). (R.A.,
32:356). The pan, Lancaster and dip processes.
Stafford, W.E., and Wright, R.A. Progress in rubber
reclaiming. R.A. (London), 31: pp. 19-21 (1950); Rubber
India, 2: No. 1, pp. 22-24 (1950). (C.A., 44:5140; S.C.L.,
28:303)
Stafford W.E. Armstead B.H. Present Day Manufacture of
Reclaim Proc. IRI 12, no. 5 Oct. 65 p 208-18 Processes are
discussed and compared. ((41) p 208 (1965))
Stafford, W.E. Standardization of reclaim, Trans. Inst.
Rubber Ind. 17 pp. 268-71 (Feb. 1942). (C.A., 36:6046)
Stafford, W.E., and Chadwick, J. Recent advances in
reclaiming Rubber & Plastics Age, 40: No. 10, pp. 1070-74
(1959). (R.A., 38:42). General discussion.
Stafford, W.E. Present trends in reclaiming. Rubber &
Plastics Age 39: pp. 495, 497-98 (1958). (C.A.,
52:19221:R.A., 36:455). The ratio of reclaimed rubber
used to total natural and synthetic rubbers consumed is
listed.
U.S. Rubber Reclaiming Co. Reclaiming rubber. Rubber J.
Int. Plast. 134: pp. 65-66 (1958). (R.A., 36:110). Designed
for low-cost manufacturing.
Digestion/Devulcanization of Reclaimed Rubber
Bowers, P.D. Improve reclaiming process. R.A. (N.Y.)
55:p.392 (1944). (S.C.L. 22:394). Steam at very high
pressure.
Butera, G. Rubber reclaiming, French Pat. 1,103,627 (Nov.
4, 1955). (To Pirelli S.P.A.) (Rev. Gen Caout., 33:230;
C.A., 49:2110; R.A., 34:237) Steam heated with mechani -
cal agitation.
Fabregat, MP.Devulcanizing and regenerating vulcanized
rubber. U.S. Pat. 2,543,315 (Feb. 28, 1951). (Same as
Austrian Pat. 165,050: Swiss Pat. 265,272; French Pat.
942,041). (S.C.L., 27:723; 28:918; 29:444). Machine.
Parrel-Birmingham Co., Inc. New Banbury rubber reclaimer
and devulcanizer R.A. (N.Y.), 66: p. 253 (1949); I.R.W.,
121: p. 261 (1949). (S.C.L., 28:166).
Hirschberger, J. Method of reclaiming or regenerating
rubber from rubber waste products. U.S. Pat. 2,313,146
(Mar. 9, 1943). (C.A., 37:5284). Charging unground rubber
in an autoclave with high pressure steam at 700 Ibs. per sq.
in. and 490° C.
Lewis J., and Lewis, S.C. Reclaiming rubber. Brit. Pat.
569,659 (June 4, 1945) (C.A., 41:6074; S.C.L., 23:344).
Scrap rubber is reclaimed by heating in steam under
pressure at 230° to 270° C. and then air is kept excluded
until the rubber cooled.
Livyi, G.V. Shurko, V.A. and Landa, I.M. Thermomechani -
cal reclaiming of colored rubbers. Legkaya Prom., No. 7: p.
30 (1956). (R.A., 35:425).
Masse, T.J. Reclaiming rubber, Austrailian Pat. 110,487
(Apr. 29, 1940). (C.A. 36:2759; S.C.L. 20:318). Treating
ground scrap with super-heated steam at 400-500° F. and
atmospheric pressure for three to six hours.
Markiewicz, W.J. USP. 3272761 Method of Reclaiming
Rubber. Improving digester process by warming then
cooling the product in 02 free atmosphere.
Maurin, A. Protected reclaiming. Rev. Gen. Caout., 36: No.
5 pp. 671-73 (1959). (R.A. 37:482). Treating vulcanized
rubber with plasticizers in an oxygen free oven.
89
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Morozov, M.A. Centralized control of the process of
reclaimed rubber. Kauchuk i Resina 20 (9) 50-1 (1961).
(R.A., 40:446). Devulcanizing tread and carcass stock.
Naudain, E.A., and Boys, C.H. Pan process of reclaiming
rubber U.S. Pat. 2,794,006 (May 28, 1957). (To Hercules
Powder Co.). (C.A., 51:12534; R.A., 36:15). Petroleum
hydrocarbon-insoluble pine wood resin.
Olanescu, G. Devulcanization and the role of softeners in
the production of reclaim. Ind. Usoara (Bucharest), 9 (8):
304-5 (1962). (R.A., 41:512) Review of soviet work.
Patentverwertungs G.M.B.H. "Hermes". Thermal, oxidizing
decomposition of artificial rubber (Buna S. Perbunan).
Italian Pat. 394,812. (S.C.L., 23:371; Rev. Gen Caout.,
21:92). Under a pressure of at least 9 atmospheres.
Plumb, J.S. New reclaimed rubber process demands auto -
matic temperature controls. Taylor Technology, Winter
(1951). (S.C.L., 29:488; R.A., 68:732)
Rennemann, H., and Gunzert, T. Reclaiming vulcanized
synthetic rubber scrap. German Pat. 716,149 (Dec. 11,
1941). (C.A., 38:2524). By treating with softener and
heating at over 200°C for a period insufficient to induce
further polymerization.
Societa Italiana Pirelli. Regeneration of vulcanized rubber.
French Pat. 865,077. (S.C.L., 23:382; Rev. Gen. Caout.,
18;149) Scrap rubber is caused to absorb a swelling agent at
a temperature below 50°C. introduced into an autoclave
and heated to devulcanization temperature with a devul -
canizing agent; the resulting product is dried and treated for
the recovery of the swelling agent. See Brit. Pat. 533,769
(Feb. 19,1941)
Solakian, H. Reclaiming of rubber. U.S. Pat. 2,317,491
(Apr. 27, 1943). (C.A., 37:6160). Immersing in water at
devulcanizing temperature and under pressure.
Tefft, R.F. Treatment of rubber goods. U.S. Pat. 2,321,114
(June 8, 1943). (C.A., 37:6908). Recovering textile materi -
al by digesting at elevated temperature with sulfur, a
reverting type vulcanization accelerator, and sufficient
rubber solvent to dissolve the rubber.
Terzi, Attilio, Reclaiming rubber and a pressure heater for
carrying out the process. Italian Pat. 394,692. (Kautschuk
p. 70, Oct.-Nov., 1943).
Equipment For Reclaiming Rubber
Anon Kunstst Berater, 12, no. 3, March 1967, p. 178
Machinery for reclaiming film scrap.
Baramboim, N.K., and Chimil, A.M. Mechanical reclaim of
colored rubbers Nauchn, Trudy. Mosk. Tekhn. Inst. Legk.
Prom., pp. 18-23 (1958). (R.A., 37:507). Freezing the
vulcanizate with liquid nitrogen and fragmenting on the
mill.
Breenan P. Old Tires. Austin Magazine 1964, 38, #10 p
41-3. A dry rapid automated way to crumb rubber (United
Reclaim Ltd) and some uses.
Condux - Werke H.A. Merges KG GP 1217753. Commi -
nuting Mill for reclaiming waste Bulky Plastics Moldings eg.
bowls etc.
Dasher P.J. Reducing scrap vulcanized rubber to finely
divided particles U.S. Pat. 2,853,742 (Sept. 30,1958). (To
Dasher Rubber & Chemical Co.) (C.A. 53:3758; R.A.
37:236). The object of the invention is to reduce vul -
canized scrap to a fine dry powder.
Gul. V.E. Gelperin, N.I., Kaplunov, YN. Shokhim, I.A.,
Vilnits, S.A. Ilin, N.S., and Tsarskii, L.N. Comminution of
vulcanized rubber articles. Russian Pat. 110,973 (May 27,
1958). (R.A., 36:407). Cooled to -60 to -80°C before being
comminuted.
Gul. V.E. Vil'ntis, S.A. Gel'pebin, N.I. Ilin N.S. Kaplunov,
Y.N., Tsarskii, L.N. and Krsikova, G.Z. Developing a
method of grinding cooled rubbers Kauchuk i Rezina 17:
No. 10, pp. 22-28 (1958). (R.A., 37:252). Experiments on
used car treads.
Gunther, A. Process for reclaiming rubber. U.S. Pat.
2,794,057 (May 28, 1957) (C.A., 51:12533). Grinding and
treating with a swelling agent.
Jaeckering, G. Pulverising and comminuting thermoplastic
material Brit. Pat. 915,255 (Jan. 9, 1963). (R.A., 41:230).
The precrushed material is whirled and comminuted in a gas
flow, with at least 30,000 parts by volume of gas at
atmospheric pressure per part by volume of starting
material, the treatment time being not more than 1.2 sec.
Jayne, W.M. USP 3190565 Process for Grinding Rubber.
Materials which tend to agglomerate are ground with
polyolefin fines.
Joyce, W.J., and Geyer, H.D. Shredding rubber. U.S. Pat.
2,318,693 (May 11,1943). (C.A., 37:6157; S.C.L., 21:211.
Explosion with ammonia.
Knowland, T. M. Grinding of rubber scrap. U. S. Pat.
2,412,586 (Dec. 17, 1946). (To Boston Woven Hose &
Rubber Co ). (C.A., 41:5335; S.C.L., 25:157).
Marshall J. scrap chopping machine. Plast. Rubb. wekly 60,
26 Feb. 65, p. 8. Accommodates material 12 x 9".
Mitrovic, L. New Method of reclaiming natural rubber
vulcanization which do not contain textiles. Hemiska
Industrija, 11: No. 1, pp. 106-07 (1956). (R.A., 35:425).
Ground on fluted cracker rolls.
Reclaiming scrap, Plastics (London), 23: p. 366 (1958).
(R.A., 36:568). Pelleting scrap.
G. Scott & Son, Ltd. Recovery of rubber from reject tires.
Chem. Processing, 5: No. 7, p. 25 (1959). (R.A., 37:515).
The tires are put through a prebreaker
90
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Sprout, Waldron & Co., Inc. Monarch ball-bearing attrition
mills. (Bulletin). (S.C.L., 21:283). Describing mills used for
grinding rubber.
Tugov. I.I. and IP'Ina, E.K. Comminution of the carcass of
wornout tires in a frozen condition. Nauchu-Issled. Tr.
Vses. Nauc Issled. Inst. Plenochuykh Materialov i Iskusstv.
Kozhi. 2: 124-30 (1960): Ref. Zh. Khim., 1963 abstr.
13T428.(R.A. 41:543).
VVendrow, B.R. Production of reclaimed rubber in discrete
particle form. U.S. Pat. 2,767,149 (Oct. 16, 1956). (To
U.S. Rubber Reclaiming Co.). (C.A., 51:6202; R.A.,
35:262). Process of subdividing reclaimed rubber as it
comes from a reclaiming apparatus.
Fiber, Rubber, Metals Separation
Allis-Chalmers Mfg. Co. Preliminary metal removal elimina -
ted in new rubber reclaiming process. R.A. (N.Y.), 68: pp.
323-24(1950). (S.C.L., 29:110).
Amphlett, P.H., Hughes, A.J. and Twiss, D.F. Reclaiming of
vulcanized rubber containing cellulose. Brit. Pat. 573,045
(1945). (To Dunlop Rubber Co., Ltd.) (C.A., 43:5992;
S.C.L., 24:36). Hydrogen peroxide as an oxidizing agent.
Bailey, E.L. Removal of bonded rubber. U.S. Pat. 2,291862
(Aug. 3,1942). (C.A., 37:1059; S.C.L., 20:382).
Blow, C.M. Estimation of small percentages of rubber in
fibrous materials. I.R.J., 102: pp. 719-22 (Mar. 14, 1942);
repr. in Rubber Chem. Tech., 15: pp. 672-77 (1942).
(C.A.,36:5381). General discussion.
Boyles, R.M., and Sullivan, DJ. Mechanical separation of
fiber in rubber reclaiming. Rubber World, 137: pp. 256-58
(1957). (R.A., 36:87). An illustrated description is given of
apparatus used in the main factory of the Midwest Rubber
Reclaiming Co.
Broomhead, F. and Priestley, J.J. Debonding of rubber
from metal U.S. Pat. 3,034,774 (May 15, 1962). (To W.C.
Holmes & Co., Ltd. and Andre Rubber Co., Ltd.) Brit. Pat.
863,846 (29 March 1961).
Butera, G. Removal of fabric in rubber reclamation. Italian
Pat. 502,398 (Nov. 29, 1954). (To Pirelli). (C.A., 51:7751;
R.A.; 35:425). Autoclaved rubber is comminuted, plunged
in alkaline water and the carbonized fabric is removed.
Carr, R.K., and Busenburg, E.B. Reclaiming fiber-reinforced
rubber. U.S. Pat., 2,567,802 (Sept. 11, 1951). (To Good -
rich). (C.A., 45: 290; S.C.L., 29:1010).
Dasher, P.J. Reclaiming composite material, U.S. Pat.
2,498,398 (Feb. 21, 1950). (To Goodrich). (C.A., 44:3733;
S.C.L., 28:399). Mineral acid to degrade the cellulosic fiber.
Dasher, P.J. Removing cellulose fibers from scrap rubber or
other acid-resistant material. Brit. Pat. 752,518 (July 11,
1956). (To Dasher Rubber & Chemical Co.). (R.A.,
34:509). Scrap with a mineral acid.
Demidov, G.K. Sergeeva N.L. Production of a Fiberous
Filler from waste rubberized cord. Kauch i Rezina 25, no.
5, May 66, p 44-6.
Deutsche Asbestwereke George, Reinhold & Co. Recovery
of fibrous material from rubber containing products.
French Pat. 873,051 (June 29, 1942) (Chem. Zentr. 114:
Part II, 1597)
Deutsche Asbestwereke G. Reinhold & Co. Reclaiming
fibers from rubberized material containing such fibers. Belg.
Pat. 428,780 and Fr. Pat 839,597. (C.A., 33:8448; S.C.L.,
17:776). Fibers are removed from scrap tires in machines
after swelling, fibers obtained are spun and rubber is
powdered.
Dixon, H.L. Separating scrapped vulcanized rubber. U.S.
Pat. 2,304,554 (Dec. 8, 1942). (C.A., 37:2960: S.C.L.
21:45). Separating fiber rich portion from rubber rich
portion by the difference in the way the scrap pieces
bounce.
Dorris, T.B. Fiber-free rubber for reclaim. Rubber Age, 71:
pp. 773-80, 821 (1952). (C.A., 46:11748; R.A., 30;528). A
process and apparatus are described.
Erygin, E.N. Machine for removing rubber from Rein -
forcing Elements. Soviet Rubber Technol/Engl. Transl/Vol.
24 No. 3, Page 50 Mar 1965 Len. 3 Lang. Eng.
Fujita, A. Tomihisa, H. and Takamatsu, T. Removing fibers
from vulcanized rubber by using cellulose-decomposing
enxymes. Japanese Pat. 5,585 (July 26, 1957). (C.A.,
52:17780; R.A., 37:192). The product is washed with
water and dried.
Gerndt, P.G., and Hannum, J.A. Method of removing
rubber from metal. U.S. Pat. 2,406,458 (Aug. 27, 1946).
(To U.S. Rubber). (C.A., 41:308; S.C.L., 24:515).
W.C. Holmes & Co., Ltd. De-bonding process. Rubber J.,
133: p. 170 (1957). (R.A., 35:509). The Holmes-Andre
de-bonding process.
Hughes, A.J., Twiss, D.F., and Dunlop Rubber Co., Ltd.
Treating vulcanized rubber containing embedded textile
fibrous material. Brit. Pat. 553,674 (June 1, 1943). (C.A.,
38:5435; S.C.L.,21:24)
Il'In, N.S. Tugov, I.I. and Arkhangel' sku, N.A. Spinnable
fiber from cords from tire covers. I. Nauchn-Issled. Tr. Vses
Nauchn-Issled Inst. Plenochnykh Materialov i Iskusstv.
Kozhi, 1960 (12): 49-57; Ref. Zh. Khim., 1963: abstr.
14T387. (R.A., 14:543).
Lamb, L. D. Method of separating rubber or rubberlike
material from metal. Brit. Pat. 844,500 (Aug. 10, 1960).
(To British Oxygen Research & Development, Ltd.). (R.A.,
38:641). Use of liquified atmospheric gas.
91
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Lee, J. A. New products from wood. Chem. & Met. Eng.,
47: pp. 95-98 (Feb., 1940). Including use of the Masonite
gun to "explode" pieces of scrap tires to separate the
rubber from the fabric.
Lewis, J. Lewis, S. C., and Rubber Improvement, Ltd.
Reclamation of waste rubber. Brit. Pat. 528,196. (S.C.L.,
18:845). Separation of canvas from rubber.
Litchfield, L. G. Method and means for stripping thermo -
plastic sheathing from cables, armored hose and the like.
Brit. Pat. 967,377 (Aug. 19, 1964). (To L. B. Plastics,
Ltd.). (R.A., 42:622).
Masse, T. J. Separating textile material from rubber.
Australian Pat. 111,637 (Sept. 25, 1940). (C.A.,
36:3067:S.C.J., 20:323). Passing ground scrap through an
electrostatic separator, which retains the fabric threads.
Masse, T.J. Method and apparatus for separating textile
material from rubber. U. S. Pat. 2,317,210 (Apr. 20, 1943).
(C.A. 37:6160).
Mazzoni, F. Treatment of rubber scrap for reclaim. French
Pat. 1,038,502 (Sept. 29, 1953). (R.A., 32:268; Rev. Gen
Caout., 31: 206). Separation of cellulose material by
aqueous solutions of mineral acids.
Merges H. A. Device for Separation of Rubber and Textile
from their Bonded Mixture. B. P. 980698. Separation of
rubber and cord and cord by size.
Muraoka Rubber Industry Co. Separation (removing) of
fibers in the process for manufacturing reclaimed rubber.
Japanese Pat. 4,982/58 (1958). (R.A., 485). Waste rubber is
continuously thrown into the gap between two rolls.
North British Rubber co. BP 1034244 Separation of Metal
and Rubber. Crumbing, sizing, magnetic separation, sizing.
Osipovskii, B. Y. and Kozlovskaya, A. V. Removal of fibers
in reclaiming sodium-bivinyl rubber. Kauchuk i Rezina, No.
10, pp. 4349 (1940). (C.A., 35:2031:I.R.W., 104:63)
Osipovsky, B. Y. and Volkova, Z.A. Mechanical methods of
separating fabric from rubber in reclaiming rubber from
tires, Legkaya Prom., 4: No. 4-5 pp. 14-19 (1944). (C.A.,
38:6610; S.C.L., 23:153)
Pirelli Societa Per Azioni. Reclaiming rubber from vul -
canized rubber, and destroying textile material in vul -
canized and unvulcanized rubber scrap. Brit. Pat. 708,788
(May 12, 1954). (R.A., 32:356). Aqueous alkali in an
autoclave.
Ray, P.A. Basic Ideas Concerning Flotation in the Removal
of Rubber from Paper. Paper Mill, 61: No 51, pp. 13, 18-19
(1938). (Chem. Zent. 110:1:2608; S.C.L., 17:556).
Rubber reclamation aids the plastics industry. Plastics
(London) 24: pp 27-28 (1959). (R.A., 37:192). The fiber
recovered from waste rubber is more suitable as a filler for
thermosetting molding materials than new ground cotton
linters.
Seifert, W., and Schindler, H. Felt-like material from corn
tire waste. German Pat. 1,001,508 (March 21,1957). (R.A.,
38:263; C.A., 53:22982). Carbon tetrachloride.
Stewart, W. D., Crawford, R. A., and Miller, H. A.
Defibering of ground rubber scrap with cellulose-decom -
posing fungi. Rubber World, 127: pp. 794-96, 801 (1953).
(C.A., 47:7810; R.A., 31:274).
Tefft R. F. Treatment of rubber goods. U. S. Pat.
2,321,114 (June 8, 1943) (C.A., 37:6908). Recovering
textile material by digesting at elevated temperature with
sulfur, a reverting type vulcanization accelerator, and
sufficient rubber solvent to dissolve the rubber.
Thiberville, J. Recovery of textiles agglomerated' with
rubber by separation especially those contained in belting
and tires. French Pat. 880,430 (1943). (S.C.L., 24:40).
Thompson, H. H., and Moore, D. V. Method of reclaiming.
U. S. Pat. 2,409,402 (Oct. 15, 1946). (To Wingfoot Corp.)
(C.A., 41:620; S.C.L. 24:608). A rubber-to-metal bond is
disintegrated by exposure to a gaseous mixture of steam
and the vapor of a rubber softening oil at 300 to 425° F.
Tokyo Rubber Industry Co. Removing fibers from vul -
canized rubber by cellulose-decomposable enzyme. Ja -
panese Pat. 5,585/57 (1957). (C.A., 52:17780; R.A.,
36:44).
Trampiron detector. R.A. (N.Y.), 49: pp. 200-01 (1941).
(S.C.L., 19:598). For detecting the presence of nails or
tacks in sheeted reclaim.
Tugov II. Gorokhouskaya L.L.J. Text. Inst. Abs. 56 #11
Jan. 66 p 779 use of Man Made Fiber Reclaimed from Worn
Old Tires. Reclaimed material is blended with wool to make
felts and suiting material.
Vil'nitis, S.A., Gel'perin, N. L, Gul', V.E. Kaplunov, Y. N.
and Krivopalova, L. P. Method of removing fabric from
comminuted rubber-fabric materials. U.S.S.R. Pats.
146,028-9 (Apr. 6,1962). (R.A., 40:426,436).
Wollfson, B. L. and Chaiko, V. S. Mechanical press for
baling textile waste in the reclaim industry. Kauchuk i
Rezina, 22 (11): 45-6 (1963); Soviet Rubber Technol.
(English Transl.) 22 (11): (1963). (R.A., 42:491).
Future and Potential of Reclaimed Rubber
Alexander, J. W. and Davis, C. L. Process for agglomerating
fine rubber particles. Adding oil emulsion to the water
slurry containing fines of oil-extended rubber. U. S. Pat.
3,130,160 (Apr. 28, 1964). (To Phillips Petroleum Co.)
(C.A., 61:2892,5888).
Dhingra, D. R. and Ghatak, S. N. Utilization of waste
vulcanized rubber in industry. Proc. Ann. Convention Oil
Tech. Assoc., India, 3: pp. 8-14 9A., 45: 9298; R.A.,
30:42).
92
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Dougan, L. D., and Bell, J. C. Synthetic rubber waste
disposal. Munic Utilities, 88: No. 9, pp. 62-65, 97-99
(1950).(C.A.,44: 11155; S.C.L., 29:168).
Gutman, A. Problem of Increasing and Improving the
Production of Reclaimed Rubber. Kauchuk i Resina, No.
10, pp. 9-13 (1937). (C.A., 32:4380; S.C.L., 16:525).
Howroyd, R. Reclamation of industrial wastes. III. Rubber
reclaiming adapts itself to synthetic. Ind. Fibres, Synthetics
& By-Products, 7: pp. 330-38 (1945). (C.A., 40:6874;
S.C.L., 25:147).
International Rubber Study Group Tokyo May 1964
London 1964, p 50. Review of the present and prospective
position of reclaimed rubber.
McCollum, D. L. Reclaimed rubber-past, present, and
future. Rubber. Age N. Y. 89 (2), 304 (1961). (R.A.,
39:391).
Nourry, A. Reclaimed Rubber. Its development. Applica -
tion and Future. London: Maclaren & Sons, Ltd. 116 pp.
(1962).(R.A.,40:347)
Placak, 0. R. and Ruchhoft, C. C. Study of wastes from the
synthetic rubber industry. Sewage Works J., 18: pp.
1169-81 (1946).(C.A.,41: 1869; S.C.L., 25:468).
Stafford, W. E., and Wright, R.A. Recent progress and
developments in reclaiming. Rubber Age & Synthetics, 33:
pp. 132-35 (1952). (C.A., 46:11749; R.A., 30:278). A.
Review
Sturtevant Mill Co-Midwest Rubber Reclaiming Co. Re -
clamation of rubber. Chem. Process (Chicago), 9 (2): 18-9
(1963). (R.A., 41:182). Old tires are used.
Dagaev, PP. Aqueous dispersions of reclaim. Legkaya
Prom., No. 7-8, pp. 21-22 (1944). (C.A., 39:4515; S.C.L.,
24:37). Patent literature reviewed.
Elliott, P.M. Reclaims and reclaiming. (Abstract of paper
presented at Yale University, April, 1942). Chem. Eng.
News, 20:pp. 1223-25, 1252-53 (Oct. 10, 1942). (C.A.,
36;7361; S.C.L., 20:411). History of reclaiming.
Esch, W. Reclaim. Gummi-Ztg., 57: pp. 121-22 (1943).
(C.A., 38: 6610; S.C.L., 23:150). Review, discussion and
development, including notes on methods of analysis.
Forty years of reclaiming at the Pequanoc Rubber Co.
I.R.W., 105: No. 1 ,p. 39 (Oct. 1941).
Hader, R.N. and LeBeau, D.S. Rubber reclaiming. Ind. Eng.
Chem. 43: pp. 250-63 (1951). (C.A., 45:3186; S.C.L.,
29:290). A review.
Kawaguchi K. Nippon Gomu Kyokaishi, 38, no. 9, (1966) p
755 Recent Situation of Reclaimed Rubber in Japan.
Kilbourne, F.L., Jr. Reclaiming synthetic rubber. R.A.
(N.Y.), 64: pp. 581-89 (1948). (C.A., 43:3647; S.C.L.,
27:57,346). Review.
Lapadu-Hargues, P. Reclaimed rubber industry in the
United States. Rev. Gen. Caout., 25: pp. 16-19 (1948).
(C.A, 42:4790; S.C.L., 26: 296). History and economic
role.
Lever, A.E. Reclaim - natural and synthetic. I.R.J., 123:
pp. 12,14-16 (1952), (C.A. 46:11737; R.A., 30:325). A
review.
History and Review of Reclaimed Rubber
Anon Reviews and Bibliography Kauchuk I. Rezina Vol. 25
No. 9 Page 58 Sept. 1966 Len. 1 Lang. Rus.
Ball, J.M. What is reclaimed rubber and how is it made?
(Abstract only). Rubber Age, 83: p.853 (1958). (R.A.,
36:506). The leading methods of reclaim are: digestive
process, heater or pan process, high pressure steam process
and Lancaster-Banbury process.
Ball, J.M. "Reclaimed Rubber-The Story of an American
Raw Material". (Book, published, by the Rubber Reclaim -
ers Assn.). (C.A., 41:5747; S.C.L., 25:632; I.R.J., 113:16)
Bostrom, S. Reclaiming of scrap rubber. Gummi-Zig.,
54:p.698 (1940). (C.A., 35:1667). Review and discussion
of some patents.
Ceresa, R.J. Mechanism of reclaiming. Rubber Plastics
Weekly 140 (14), 539-40 (1961). (R.A., 39:345). Mechani -
cal energy, heat and oxygen are the fundamental bases of
all reclaiming processes.
McRoberts, D.C. Contributors rubber compounding pro -
gress: Philadelphia Rubber Works Co. I.R.W., 93:45-7 (Jan.
1936).
Midwest Rubber Reclaiming Co. Reclaiming rubber. Royle
Forum, 35:pp. 4-7, 10 (1946). (S.C.L., 24:417). History of
reclaiming.
Riemer, Manufacture of reclaim. Gummi Bereifung, 28: No.
1,P. 13 (1952) (R.A., 30:99). Review
Rubber Age — History and Review: Development 50 years
- May 1967
Rubber Manufacturers Association, Inc. Summary of data
on reclaimed and scrap rubber, (mimeographed bulletin).
(S.C.L., 21:45).
Rubber reclaim. Rubber India, 3: No. 9, pp. 15-18; No. 10,
pp. 11-14 (1951). (R.A., 30:224). Review.
Sorin G. Facts about Reclaimed Rubber. Chem. Rev.
(Japan). 4: pp. 281-90 (1938). (C.A., 32:9559; S.C.L.,
17:26),
93
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Stafford, W.E. Utilization of waste rubber. Rubber and
Plastics Age 39, 495-8 (1958) The history and uses of
ground scrap.
Stafford, W.E., and Sargent D. Present day manufacture
and use of reclaimed rubber. Rubber J & Int. Plast. 138:
No. 9, p. 310 (1960). (R.A., 38:211). Natural and
synthetic.
Stafford, W.E. and Wright, R.A. Modem theories of rubber
reclaiming. Proc. Inst. Rubber Ind., 4: pp. 105-14 (1957).
(R.A., 35:425). General principles of rubber reclaiming.
Sugimoto, S., and Minakata, T. (IV); Nasu, K. (V) and
Endo K. (VIH-XIII). Studies on reclaimed rubber. J. Soc.
Rubber Ind., Japan, 14: pp. 509-15, 579-89, 609-21,
621-33, 69007, 761-70, 770-74, 827-35 (1941). (C.A.,
42:6151; S.C.L, 26:814). Parts IV through XIII of a series.
Tech. Review 1967 Rubber Age Oct. 1967 p. 51
Thompson, H.H. Manufacture and use of regenerated
rubber. (Abstract only). Rubber World, 126: p. 387 (1952).
(R.A., 30:365). Review.
Wolf, R. Old Tires Don't Fade Away Rubber Age/NY/Vol.
100 No. 2 Page 68 Feb. 1968 Len. 6 Lang. Eng.
Wolf, H.P. Story of scrap rubber. (Book). (C.A., 38:1914)
Relates the history of scrap rubber. Schulman (Printer)
Wendrow, B.R. Reclaimed rubber-its place in the rubber
industry (Abstract only). Rubber World, 140: pp. 275-76
(1959). (R.A., 37:375). The early history of the reclaimed
rubber industry.
Methods/Processing of Reclaimed Rubber
Alexander, P.I. Solution process of rubber reclaiming.
German Pat. 705,363. (C.A., 36:2447; S.C.L. 20; 215;
Chem. Sentr. 112: Part II, 824).
Amphlett, P.H., Hughes, A.J., Twiss, D.F., and Dunlop
Rubber Co., Ltd. Regeneration of synthetic rubberlike
materials and utilization of this regenerated material. Brit.
Pat. 564,514 (Oct. 2, 1944). (To Dunlop). (C.A., 40:3640;
S.C.L., 22:393). Reclaiming of polymers of butadiene alone
or with styrene or acrylonitrile by subjecting to mechanical
working with or without a softener.
Augenstein, J.G. and Sverdrup, E. New Reclaiming Process.
(Abstracts only). R.A. (N.Y.), 65: p. 63 (1949); I.R.W.,
120: p. 92 (1949) (S.C.L., 27:511) Dip reclaiming.
Ball, J.M. and Randall, R.L. Reclaimed rubber during
reconversion I.R.W., 114: pp. 368-73 (1946). (C.A.,
40:5950; S.C.L., 24:461). See also Can. Chem. Process
Ind., 30: pp. 24-28,93 (1946). (C.A., 40:5286).
Banbury, F.H., Comes, D.A., and Schnuck, C.F. Reclaiming
scrap vulcanized rubber. U.S. Pats. 2,461,192 and
2,461,193 (Feb. 8, 1949) (To Lancaster Processes, Inc.).
(S.C.L., 27:686).
Barabonoy, P.P. Reclaiming synthetic rubber by the ther -
mal swelling method Kauchuk i Resina, No. 10: pp. 70-72
(1939). (C.A., 36:2756; S.C.L., 20:316).
Barbanov, P., and Leonovich, V. The acid Alkali method of
reclaiming scrap rubber. J. Rub. Ind. (U.S.S.R.),
12:1048-50 (1935). (C.A., 30:6981).
Bata Narodni Podnik, Regeneration of natural or synthetic
rubber. Brit. Pat. Appl. 18,539/47 (Aug. 6, 1953). (R.A.,
31:455). Mechanical homogenization in a closed space.
Bemelmans, E. Conversion of old tires with their entire
constitutents into plastic material. "Recueil des Communi-
cations-Ccngres International due Caoutchouc" Repr. in
G.Z., 51: pp. 917-18 (1937); LeCaout., 34: pp. 258-59,
289 (1937). Abst. in R.A. (N.Y.), 41: No. 5, p. 313 (Aug.
1937) (S.C.L., 15:460 and 682).
Beverly J.A. USP 3318838 Reclaiming and Treating
Synthetic Rubbers. Scrap is heated in reclaiming oils to
420° to drive off water and soften particle for use.
Bielenky, X.I. Technical reclaiming of a combination of
natural and synthetic rubbers. J. Rub. Ind. (U.S.S.R.),
12:68-74 (1935); Rev. Gen. Caout., p. 29, July-Aug. 1936,
(S.C.L., 14:674).
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An oil may be included.
Gunzert,T.,Renneman, H., and Continental Gummi-Werke
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I.G. Farbenindustrie, A.-G. Reclaiming rubber vulcanizates.
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Imperial Chemical Industries Ltd. Reclaiming of foamed
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Keleti, Z., and Wolfner Gyula Estarsa Gumigyar, R.T.
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Khan, A.A., Majumdar, B.C., and Siddiquit, S. Depolymeri -
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mixture of a swelling agent, a softening agent and a
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Kirby, W.G. Rubber reclaiming process. Can. Pat. 403,630
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Kirby,W.G. and Steinle, L.E. Reclaimation of rubber. U.S.
Pat. 2,279,047 (April 7, 1942). (To U.S. Rubber). (C.A.,
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Kluckow, P. Means of renovating rubber products and
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Laboratorire de la Societe Anonyme des Matieres Colorants
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Processing of reclaimed rubber and the effects of small
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Gummi-Ztg., 56: pp. 27-28, 39-41, 51 (1943). (C.A.,
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LeBeau, D.S. Reclaiming process for synthetic rubber.
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Lebedey, P.D. Autoclave for reclaiming rubber by the
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LeBras, J., and Haehl, A. Preparation of reclaim. Rev. Gen.
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Lemercier, A. Depolymerization breakdown and reclaiming
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Lemercier, A., and Societe Electro-Cable. Process for the
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Litvinenko, A.G. Dyunnina, V.G. and Tugov, I.I. Automa -
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McCowan, W.A., and Twiss, D.F. Reclaiming vulcanized
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Mellersh-Jackson, L., Jr. Reclaiming rubber or rubber scrap
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Michelen & Cie BP 1032011 Regenerating Rubber of a
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Mishustin, I.U. Reclaiming black synthetic rubber. Ko -
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Montecatini Soc. Gen. P.P. 1429092 Regeneration of
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Polymers heated to 175-225°C, 2-10 hours.
Navone, J.O. Reclaiming rubber. U.S. Pat. 2,487,666 (Nov.
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Newton, R.G. and Scott, J.R. (1) Reduction of rubber
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Oishi, Y. Apparatus for reclaiming rubber material. U.S.
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Ossipovskii, B.J. Wergiless, F.A. and Manontov, B.W.
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Plants using the solution method. Kauchuk i Rezina, No. 4:
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Panoulleres, G. Bemelman's process for the regeneration of
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Peterson, C.H. Reclaimed rubber U.S. Pat. 2,804,651 (Sept.
3, 1957). (To U.S. Rubber Reclaiming Co.). (R.A.,
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Pluhacek, R., and Svit, Narodni Podnik Reclaiming process.
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Reclamation of rubber scrap. Chem. Age (London), 46: p.
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Reclaiming of S.K. Kauchuk i Rezina, No. 11; pp. 63-73
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Reclaiming processes for rubber. Oil, Paint & Drug Reptr.,
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Reclaiming rubber. Elec. Review (London), 130: pp.
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Robinson, T. Reclaimed rubber and method of producing
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Rostler, F., and Mehner, V. Rubber reclaiming. U.S. Pat.
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Rozhdestverskii, S.I. Reclaiming of tires by the alkali
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Rubber & Plastics Compound Co., Inc. Nervastral rubber
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Rubber reclaiming. Chem. & Met. Eng., 48:pp. 112-15
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Schenck, E.L. Reclaiming tires. U.S. Pat. 2,471,043 (May
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Selivanova, A.I. Reclaiming of Rubber from Synthetic
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Shokhin, I.A., and Tikhonovich, L.V. Investigation of the
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Societe Anon. Des Penumatiques Dunlop. Reclaiming
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Societe Industriele du Caoutchouc and L'Eplattenier, G.
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High frequency alternating electric field.
Societa Italiana Pirelli, Regeneration of vulcanized rubber.
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the point of dissolution, heating in the presence of a
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Societa Italiana Pirelli, Reclaiming old rubber by the alkali
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Sorochenko, A.F. Rudskoi, R.B. Gaivoronskaya, R.I. Polo -
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Twin screw mixer for preparing reclaim and rubber com -
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Stafford, W.E., Armstead, B.H. Proc. Inst. Rubber Ind.
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Stafford, Reclaim Syn Elastomers Vol. 40, No. 4, Page
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Stefan Picker & Alfred Stieler A New Method of Re -
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Svetajeva, J.M. Reclaiming synthetic rubber by the thermal
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Tandy, W.A. and Woods, F. Technology of reclaim. Indian
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Thermodynamic reclaim: Energy absorption fundamental
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Treiman, O.A. Reclaiming synthetic rubber galoshes by the
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Treves, A. Reclaiming vulcanized rubber. French Pat.
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Triska E. Rubber Trade Enterprises Ltd., London 1967 p.
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Tsvetaeva, E.M. Drugovskaya, M.N. Svereva, N.I. Kolkhir,
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Tsvetaeva, E.M. Influence of the bath and the method of
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United States Rubber Co. Reclamation of rubber. Brit. Pat.
522,183. (B.C.A. (B) 631-1940). Producing cellulose-type
reclaimed rubber by mixing fiber-containing rubber stock
with a solution of sale, and treating.
United States Rubber Co. Method of reclaiming rubber.
Brit. Pat. 965,177 (July 29,1964) (R.A., 42:545).
United States Rubber Co. Reclaiming mixtures of vul -
canized natural rubber and synthetic rubber scrap. Brit. Pat.
687,054 (Feb. 4, 1953). (R.A., 31:227).
United States Rubber Co. Reclaiming waste polychloro -
prenes. Brit. Pat. 557,803 (Dec. 15, 1943). (C.A., 39:3462;
S.C.L., 22:14).
United States Rubber Co. Reclaiming of vulcanized scrap
natural and or synthetic rubber. Brit. Pat. 747,997 (April
18,1956). (R.A., 34:332).
U.S. Rubber Reclaiming Co. Rubber reclaiming apparatus.
Brit. Pat. 902,943 (Aug. 9, 1962). (R.A., 40:577).
United States Rubber Reclaiming Co., Inc. Extrusion
apparatus for use in reclaiming rubber. Brit. Pat. 729,825
(May 11, 1955). (R.A., 33:381). A screw rotating in a
cylindrical casing.
U.S. Rubber Reclaiming Co., Inc. Method for reclaiming
rubber British Pat. 610,812 (S.C.L., 27:158).
Usines Mongroises de Caoutchouc, Plasticizing products
made from vulcanized synthetic rubber. French Pat.
889,384. (S.C.L., 23:234; Rev. Gen. Caout., 21:42).
Reclaiming method.
Van Amerongen, G.J. Depolymerizing by heat. Netherlands
Pat. 63,006. (To Rubber Stichting). (C.A., 43:5231; S.C.L.,
27:742).
Vinitskii, L.E. Use of seeding in the preparation of reclaim
mixes. Kauchuk i Rezina, 16: No. 9, pp. 33-34 (1957).
(C.A., 52:10627; R.A., 36:160).
Watson, W.F. Degradation of natural rubber in a solution in
vacuo. Trans. Inst. Rubber Ind., 29. pp. 202-14 (1953);
repr. in Rubber Chem. Tech. 26: pp. 798-809 (1953).
(C.A., 48:8572; R.A. 31,453). Degrades in the absence of
oxygen.
Wettly, J. New Technique for reclaiming: The "dip pro -
cess", Rev. Gen. Caout. 29: pp. 192-94, 206 (1952). (C.A.,
46:4837; R.A.,30:176).
Weydert, L. Reclaiming rubber by use of high pressure and
material for use in process. Addition No. 51,693 to French
Pat. 872,614 (1944), (S.C.L., 24:37; Rev. Gen. Caout.,
21:11).
White, C.M. Oxidized tall oil and petroleum oil composition
method of making and method of reclaiming rubber. U.S.
Pat. 3,043,786 (July 10, 1962). (C.A., 57:10015; R.A.,
41:107). A small amount (0.5 to 2.5% by weight) of tall oil
oxidized as described is added to rubber being reclaimed.
An example describes the reclamation of SBR.
Zachesova,G.N.,Dogadkin, B.A., and Shokhin, A.I. Method
of reclaim of vulcanized rubber by dispersion. Russian Pat.
127,382 (March 25, 1960). (R.A., 38:328; C.A.,
54:19004).
Zemek, J. and Lukovsky, L. Method of treating unvul -
canized waste formed in the production of cellular rubber.
Czech. Pat. 103,971 (June 15, 1962): Ref. Zh. Khim.,
1964: abstr. 3S673P. (R.A, 42:224).
Zielinski W. Properties and use of reclaim obtained by
Radiation. Ref. Zh. Khim 1965 abs 12S563 P Magyar kern
lapja 19.6 (1964) p. 300. Rubber waste processed with Co
radiation, loss in tensile.
Miscellaneous
Abons, G. Distillation of the Solvent in the Reclaiming of
Rubber by the Solvent Method. Kauchuk i Rezina, No. 1,
pp. 36-48 (1937). (C.A., 32:4003; S.C.L., 16:525).
Ball, J.M., and Randall, R.L. Rate of cure of present day
while tire reclaimed rubber. I.R.W., 124: pp. 53-57, 66
(1951). (C.A., 45:6420; S.C.L., 29:290,568; R.A., 68:565).
Dzottsoi, S.K. Investigation of the influence of reclaim on
the working properties of synthetic sodium butadiene
vulcanizates SB. tr. Azerb. Med. Inst, 4: pp. 324-28
(1958). (R.A, 38:222).
Galan, R.R. Reclaimed rubbers. Rev. Plasticos Mod.
(Madrid), 14 (90): 1018-22 (1963); 15 (92): 134-8 (1964).
(R.A, 42:447).
Haehl, A. Mixing factors and their influence, III. Role of
reclaim Rev. Gen. Caout, 22: pp. 78-81 (1945). (C.A,
40:6874; S.C.L, 24:62).
Kochis,P.E. Process for dispersing reclaimed silicone rubber
in a sihcone gum. U.S. Pat. 3,063,975 (Nov. 13, 1962). (To
Dupont). (C.A, 58:4714; R.A, 41:329).
Mankowich, I Chiavetta, F.P. and Charter, R.A. Polymeri -
zation of monoolefins in the pi .s-r'ce of comminuted
reclaim. U.S. Pat. 3,042,634 (July 3, 1962). (C.A,
57:10036; R.A, 41.-107).
Stafford, W.E. Aging of reclaim. Trans. Inst. Rubber Ind.
17:pp 264-67 (Feb. 1942). (C.A, 36:5675).
Stafford, W.E. and Sargent, D.T. Some considerations of
reclaiming mechanisms. Rubber J. Int. Plast, 136: pp. 5-6,
39-40 (1959). (R.A, 37:112). The modern aspects of
reclaiming are discussed.
Stafford, W.E, Wright, R.A, and Sargent, D. Contribution
of the mechanism of devulcanization. Rubber J. 130: pp.
292, 294-96 (1956); Rubber & Plastics Age, 37: pp. 87-92
99
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(1957). (C.A., 50:9778; R.A., 34:236,383). Work is re -
corded on the behavior of three types of vulcanizates.
Totsch, C.H. Rubber Age, 97, no. 6, Sept. 1965, p. 79
Reclaimed Rubber in Bale Form. Advantage and disad -
vantages are discussed.
Zaionchkovskii, A.D., and Livyi, G.V. Destruction of
rubber materials in reclaim manufacture. Legkaya Prom.,
No. 9, p. 34 (1955). (C.A., 50: 22; R.A., 34:279).
Destruction is accelerated by oxidants.
Properties of Reclaimed Rubber
Babitskii, B.L. and Vinitskii, L.E. Certain features of the
structure of filled vulcanizates based on reclaim vol. 25, no.
6, p 21 (1966) Sov. Rubb. Tech.
Babitskii, B.L. Vinitskii, L.E. and Kaplunov, Ya. N.
Electrically insulating rubbers based on reclaim. Vestin.
Tekhn. Ekon INform. Nauchn. Inst. Tekhn.-Ekon. Issled.
Gas. Komiteta i Neft. Prom. PRI Gosplane SSSR, 1963 (3):
38-9; Ref. Zh Khim. 1964; Abstr. 4S389. (R.A., 42:279).
Babitskii, B.L.,Vinitskii L.E. Kauch i Rezina, 24, no. 5, May
65, p 22 Effect of the filler content of reclaim vulcanizates
on the dielectric properties of the reclaim.
Babitskii, B.L. Vinitskii, L.E. and Kaplunov, Ya. N. Dielec -
trie properties of reclaim Kauchuk i Rezina, 21 (12): 18-22
(1962): Soviet Rubber Technol. (English Transl.). 21 (12):
18-21 (1962). (C.A., 58: 11552; R.A., 42:143). Reclaim
increases the safety factor.
Babitskii, B.L., Vinitskii, L.E. Effect of filler content of
reclaim vulcanizates on the dielectric properties of the
reclaim. Sov. Rubb. Tech. Vol. 24 no. 5 p. 23 (1965).
Coe, W.S. Effect of Reclaimed Rubber on Temperature
Coefficient of Vulcanization Ind. Eng. Chem., 31: pp.
1481-85 (Dec. 1939). (C.A., 34:1513; R.A. (N.Y.), 45:283;
I.R.W., 100: No. 6, 45: I.R.J., 98:314; S.C.I., 17:682,828;
B.C.A. (6)156-1940).
Hublin, R.A. Evaluation of Mixings Containing Reclaim.
Rev. Gen. Caout. 16; pp. 297-302, 329-35 (Oct. and Nov.,
1939). (S.C.L., 18:32).
Kaplunov, Y.N., Shokhin, I.A., and Povarova, Z.G.
Mechanical properties of tread rubbers incorporating
reclaim. Tr. Mosk. Inst. Tonkoi Khim. Tekh., Nov. 6:
pp. 130-40 (1956). (R.A., 36:430).
Montu, M. Reclaimed rubbers. Rev. Gen. Caout., 37: No. 4,
pp. 487-88 (1960). (R.A., 38:433). Properties of reclaim.
Rhein Chemie Gmbh VIII-1 the addition of chloroprene
reclaim in a chloroprene rubber extrusion compound and
its effects.
Rhein Chemie Gmbh Tech Bull VIII-2 the addition of
nitrile reclaim to a nitrile compound and its effects on
properties.
Rose, H.W., Welch, W., Shaffer, C.R., Johnson, T.A.,
Busenberg, E., and Nesbit, J. Akron Group panel discussion
on reclaimed rubber. Rubber World, 125: pp. 726-30
(1952). (R.A., 30:224). Methods, properties and use of
reclaimed rubber.
Marakhovskii, M. Zakharov, N., and Pekarskaya, G. Rubber
from waste. Prom. Kooperatsiya, No. 2: p. 25 (1956).
(R.A., 35:337).
Peck, A.P. Domestic rubber "plantations": scrap rubber
reclaimed. Sci. American, 167: pp. 105-07. (S.C.L.,
21 — 145), Illustrated description of reclaiming process.
Rostler, F., and Mehner-Wilson, V. Reclaim from vul -
canized rubber scrap. German Pat. 909,041 (March 4,
1954). (To Metallgesellschaft Aktienges. Naftolen Ges.
m.b.H.). (R.A., 33:59). Refinery wastes.
Barren, H. Waste Rubber. I. The Economic Aspect. (Types
of scrap and methods of collection) R.A. (London), 19:pp.
316-17, 341 (Jan. 1939) (S.C.L., 17:67). III. Uses of
Reclaim. Ibid 20:pp. 20-21 (Mar. 1939). (S.C.L., 17:269).
Coe, J.P. Present status of rubber chemicals and reclaimed
rubber. Ind. Eng. Chem. (Ind. Ed.), 33:pp. 1347-51 (Nov.,
1941).
Gutman, A. Problem of Increasing and Improving the
Production of Reclaimed Rubber. Kauchuk i Rezina, No.
10, pp. 9-13 (1937). (C.A., 32:4380; S.C.L, 16:525).
Japanese Reclaimed Rubber (Specifications of the Society
of the Rubber Industry of Japan). I.R.J., 97:p. 419 (Apr. 8,
1939). (S.C.L., 17:236).
Kirchhof, F. Reclaim rubber as raw material. Kautschuk u.
Gummi, 3: pp. 348-50 (1950); 4: pp. 372-74 (1951).
(S.C.L.,28:966).
Plumb, J.S. Economic factors in reclaiming synthetic
rubbers. I.R.W., 112: pp. 307-08 (1945). (C.A., 39:4515;
S.C.L., 23:343). Discusses collection and grading of scrap,
processing, and marketing.
Rhein-Chemie GmbH Reclaim. A Constant and Economic
Raw Material for each rubber compound (Retorte 32E)
Mannheim-Rheinau: 1962. 46 pp. (R.A., 41:197). General
information about reclaimed rubber and its uses are
presented.
Shulan, A. A scrap rubber dealer's viewpoint. I.R.W.,
105:p. 159 (Nov. 194 ). On the expanding market for
reclaimed rubber.
Tonn, R.C. Scrap rubber. Its contribution to the national
economy. Rubber J. Intern. Plastics 140 (7). 250 (1961).
(R.A., 39:233).
Torrey, Richard F. Transportation Factors in Plant Loca -
tion Rubber Age, June 1965 p. 86.
100
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Pyrolysis
Albert, H. and Tacke, W. Method of reclaiming scrap
polyurethene U.S. Pat. 2,998,395 (Aug. 29, 1961). (To
Reeves Bros. Inc.) (C.A., 56:4957; R.A., 40:151). Burning
the resin in the air.
STUDY BY GAS CHROMATOGRAPHY OF THE PRO -
DUCTS OF POLYMER PYROLYSIS
(French)
R. Audebert
Ann Chim (Paris), 3(1):49. January-February, 1968. 18
pages. The study by gas chromatography of the products of
the pyrolysis of macromolecular compounds has undergone
enormous development during the last 15 yr. After de -
scribing the main types of apparatus employed and their
uses, the characteristics parameters are shown which allow
one to define the best conditions for pyrolysis and for
chromatography. Typical examples are given to illustrate
the applications of this technique, epg
THE INFLUENCE OF BROMINE COMPOUNDS ON THE
COMBUSTION OF POLYOLEFINS
1. EFFECTS ON THE THERMAL DEGRADATION
M D Carabine (Imperial Coll, London) C F Collins and I J
Groome (The City Univ, London) Proc Roy Soc (London)
Ser A, 306 (1484); 41, July, 1968 11 pages Hattobe, Y.
Kerosene—like product from rubber waste, Japanese Pat.
175,545 (To Oriental Rubber Industrial Co.). (C.A.,
44:8156; S.C.L., 28:1004).
Iyer, K.N. Degradation of rubber. "High Polymers Sym -
posium and Exhibition", Poona, p. 26 (1957). (R.A.,
35:475). Non-oxidative degradation of rubber is critically
examined.
THERMAL DEGRADATION OF POLYSTYRENE
G J Knight (Royal Aircraft Establish., Farnborough,
Hampshire, Engl.) J Polymer Sci, Part B, 5, #9, 855
(1967) September 3 pages Polystyrene will degrade en-
tirely to monomer under flash pyrolysis conditions if
small enough samples are taken and if the temperature
is sufficiently high. With large samples secondary reac-
tions take place due to diffusion effects. This would
explain the dimer, trimer and tetramer observed in
earlier experiments. At lower temperatures with small
samples it seems probable that the time required to
produce degradation and the lifetime of the styryl
radicals are such that secondary reactions may occur.
Lane.G.H. Rubber Journal, 150, no. 2, Feb. 68 p 44 The
case against burning used tires. Palma process versus
incineration centers.
Mochizuki, G. and Konishi, M. Rubber asphalt from waste
rubber Japanese Pat. 8, 878/57 (Oct. 18, 1957). (C.A.,
52:12446; R.A., 36:586). Heating to obtain rubber tar.
Mzourek, A. and Hladacek, M. Thermal degradation of
rubber scrap V. Contribution to extending chloroprene
rubbers, with reclaim distillates, Plaste Kautschuk 8 (7),
359 (1961). (C.A., 55:15975; R.A., 39:532). Improved life
of chloroprene rubber.
Mzourek, Z. and Mikl. O. Thermal decomposition of rubber
scrap, IV. Analysis of products obtained by scrap rubber
pyrolysis. Plaste Kautschuk 8 (1), 3-6, (2) 69-74 (1961).
(C.A., 55:26495; R.A., 39:246,294). (See also R.A.,
38:175,484,604).
Pickett, F.N. Emergency reclaim plan, R.A. (London)
23 :pp.33,34,40,57-59,66, 129-30,153-55,163 (1942).
(S.C.L., 20:185, 214:341). Discusses manufacture of a
rubber distillate.
Pespisl, J. Pyrolysis of surplus rubber and the employment
of technical dispentene. Chem. Listy 55 (10), 1210-20
1961; Chim. Ind. 88 (1), 66 (1962). (C.A., 56:11761; R.A.
40:492).
Schmidt, H. Dry distillation of vulcanized rubber. Kaut -
schuk u. Gummi, 4: pp. 21-23 (1951). (C.A., 45:6419;
S.C.L., 29:230).
APPARATUS FOR STUDY OF THE KINETICS OF
POLYMER DEGRADATION (Russian)
RAPRA
A I Sidney, Yu V Khvashchevskaya and I A Zubkov Plast
Massy, (6):61, June, 1968 2 pages. The authors describe a
static vacuum apparatus for the investigation of the thermal
and thermooxidative degradation of polymers with auto -
matic recording of the rate of absorption of oxygen, or of
the rate of evolution of gaseous degradation products, myf
THERMAL ANALYSIS OF POLYMERS
D A Smith
Rubber J. 150 (4):21. April, 1968. 8 pages.
THERMAL DECOMPOSITION PRODUCTS OF POLY -
ETHYLENE
Y Tsuchiya and K Sumi (Nat Res Council, Ottawa,
Canada). J. Polymer Sci. Part A-l, 6 (2):415. February,
1968. 10 pages. Decomposition products of polymers have
been determined by many investigators, but the results are
often conflicting because of difficulties in analyzing a large
number of products. A comprehensive analysis of the
volatile thermal decomposition products of high-density
polyethylene has been made with the latest techniques in
gas chromatography. The formation of products is ex -
plained on the basis of free radical mechanism. The
predominant process in the formation of volatiles appears
to be intramolecular transfer of radicals, in which isomeri -
zation by a coiling mechanism plays an important role in
determining the relative quantities of each product, svk
Tsvetaeva, E.M., Sidorova, R.I. Drugovskaya, M.N. and
Shokhin, LA. Synthetic softeners for reclaiming made from
rubber pyrolysis products. Kauchuk i Rezina 19 (12), 31-4
(1960): Soviet Rubber Technol 19 (12), 28-31 (1960).
(C.A., 55:20477; R.A., 39:533). The method described is
based upon the polymerizing and sulfonating action of
concentrated sulfuric acid on rubber oil.
101
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Reclaiming Chemicals, General
Baldwin, P.P. Reclaiming butyl rubber by treatment with
metalloid hydrides. U.S. Pat. 2,493,518 (Jan. 3, 1950) (To
Standard Oil). (C.A., 44:2273; S.C.L., 28:198).
Data, A.—G. Reclaiming of synthetic rubber. French Pat.
885,895 (Sept. 28, 1943). (Chem. Zentr. 115: Part I,
1140-41). Heating butadiene or chloroprene rubber with
dithiocarbamic acid derivatives, a thiazole, thiazyl sulfide,
thiuram sulfide or dibenzothiazoyl disulfide.
Bata, A.—g. Reclaiming of natural or synthetic rubber.
French Pat. 885,896 (Sept. 28,1943). (Chem. Zentr., 115:
Part I, 1047). Treating vulcanized rubber, chloroprene,
buna or butadiene rubber with organic sulfonyl chlorides
under heat and pressure.
Baudelot, P. Reclaiming synthetic rubber. French Pat.
931,228. (S.C.L., 27:685; Rev. Gen. Caout., 26:532).
Simultaneous application of heat and pressure in the
presence of a plasticizing catalyst.
Beaven, E.W.J. Rubber reclaiming oils, Brit. Pat. 932,853
(July 31, 1963). (To Shell Research, Ltd.). (C.A.,
59:11744; R.A., 41:563). The composition has an aniline
point of less than 15°C.
Beaven, E.W.J. Reclaimed oil composition for rubber. U.S.
Pat. 3,116,258 (Dec. 31,1963). (To Shell Oil Co.).
Bechtold, H.A. Reclaiming buna scrap. French Pat. 903,859
(1946). (S.C.L., 24:500; Rev. Gen. Caout., 23:82). Schist
oils with natural rubber.
Beloroxxova, A.G., and Farberov, M.I. Synthesis of alkyl
cresol disulfides as reclaiming agents for vulcanized rubber.
Uch. Zap. Yaroslavski, Tekn. Inst., 3: pp. 77-82 (1959).
(R.A., 38-484; C.A., 53:19940). Synthesis of ter-butyl
cresol disulfide.
Bennett, R.B., and Smith, G.E.P., Jr. Relationship of
oxygen to activity of GR-S reclaiming agent. Ind. Eng.
Chem. 46. pp. 1721-26 (1954); repr. in Rubber Chem.
Tech., 28: pp. 308-21 (1955) (C.A., 48:14279; R.A.,
32:510).
Bergmann, F., and Dishon, B.R. Reclaiming rubber. Brit.
Pat. 580,617. (S.C.L., 24:607; 26:450; Rev. Gen. Caout,
25:33). N-Butyl alcohol and steam.
Berryman, G.C. Process for forming a fibrous rubber base.
U.S. Pat. 2,395,987 (Mar. 5,1946). (C.A., 40:3640; S.C.L.,
24:318). Mixing ground up tire carcass stock with pine-tar,
forming the mass into a slightly compressed layer, and
cooking the layer in steam at about 338°F for about four
hours.
Beverly, J.A. USP 3318838 Reclaiming and Treating
Synthetic Rubbers. Scrap is heated in reclaiming oils to
420 to drive off water and soften particle for use.
Boyd, J.H. Rubber reclaiming solvents. U.S. Pat. 2,623,862
(Dec. 30, 1952). (To Phillips Petroleum Co.). (C.A.,
47,3605; R.A. 31:256). Cyclopentadiene.
Brown, G.L., Johnson, T.A., and Knill, R.B. Non-discolor -
ing reclaim. U.S. Pat. 2,640,035 (May 26, 1953). (To
Wingfoot Corp.). (C.A., 47:7814; R.A., 32:57). Devulcan -
izing with a light colored rosin oil.
Bruckner, Z. and Juhasz, M. Role of surface active materials
in the water-neutral rubber reclaiming process. Gumilipari
Kutato Intezet Koxlemenyei (1949-59), 1:20640 (1962).
The product is more homogeneous.
Bruner, L.B. Acyloxy-end block diorganopolysiloxanes,
U.S. Pat. 3,032,532 (May 1, 1962). (To Dow Corning
Corp.) (C.A., 57:11236; R.A. 40:604).
Bulli, M., and Societa Italiana Pirelli. Reclaim of rubber
waste. Italian Pat. 384,725. (S.C.L., 23:235; Rev. Gen.
Caout., 21:42). By an alkali product in situ, e.g., sodium
carbonate and calcium carbonate.
Campbell, C.H., and Ostermayer, R.W. Rubber reclaiming
oil. U.S. Pats. 2,447,732 and 2,447,733 (Aug. 24, 1948).
(C.A., 42:8518; S.C.L., 26:816).
Campbell, A.W. Study of the nitroparaffins and their
derivatives as heat sensitizers for compounded rubber
latices. Abstract only in I.R.J., 100: pp. 193-94 (1940).
(S.C.L., 18:601).
Campbell, C.H. Oil-resin reclaiming blend. U.S. Pat.
2,468,482 (Apr. 26, 1949). (S.C.L., 27:603).
Castello, A.D., and Dixon H.L. Reclaimed rubber. U.S. Pat.
2,278,826 (Apr. 7, 1942 To Goodrich). (C.A., 36:6376).
Preparing a nonstaining composition by admixing vul -
canized rubber, an absorbent material, and a water-insol -
uble soap, and heating the mixture in the presence of an
alkali.
Castello, A.D. Peptized vulcanizate and method of pre -
paring it. U.S. Pat. 2,211,592 (Aug. 13, 1940). (To
Goodrich). Reclaiming well-vulcanized soft rubber by add -
ing an organic material to accelerate the vulcanization and
masticating below 180°F.
Cech, C.J., and Bata, A.—G. Regeneration of synthetic
rubber composed of polymers of butadiene or its alkyl or
halogen derivatives. German Pat. 743,605. (S.C.L., 22:209;
23:380; Rev. Gen. Caout., 21:189). Heat treating with
derivatives of thiazole or dithiocarbamic acid.
Ceva, A., and Trius, V. Plasticizers in reclaiming rubber
scrap. Bol. Inst. Espan. Caucho, 3: pp. 247-58 (1957).
(R.A., 36:258).
Clarke, R.B.F.F. Regeneration of vulcanized natural and
synthetic rubber. Brit. Pat. 581,136 (1946). (To Imperial
Chemical Industries, Ltd.). (C.A., 41: 1874; S.C.L.,
24:607). High pressure steam and an alkyl-olamine.
102
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Clayton, R.E. Process for reclaiming scrap rubber with
polymer oil-sulfur mixture and composition thereof. U.S.
Pat. 2,939,850 (June 7, 1960). (To Esso Research & Eng.
Co.). (C.A., 55:21834; R.A., 39:79). Scrap rubber is
softened by an oily mixture.
Cohan, L.H., and Mackey, J.F. Carbon black in all-reclaim
tire treads. I.R.W., 107: pp. 469-70, 479 (Feb. 1943).
(C.A., 37:2217).
Continental Carbon Co. (1) Continental grades of carbon
black in all-reclaim thread stock. (2) Competitive soft
channel blacks in all-reclaim tread stocks. (Technical
bulletins). (S.C.L., 21:299).
Continental Gummi Werk G.P. 1229720 Reclaiming poly -
eurethane scrap. Regenerated by breaking down with esters
with OH groups i.e. ethylene glycol etc.
Continental, Gummi Werk A.-G. Scrap rubber. Ger. Pat.
1,150,197 (June 12, 1963); Ger. Pat. Abstr. 3 (28): 2
(1963). (C.A., 59:6599; R.A., 41:512). Before reclaiming,
scrap rubber based on discoloration (while at the same time
avoiding attack on the rubber itself) by treating with
organic peroxides in organic solvents or rubber swelling
agents.
Cook, W.S. Reclaiming rubbers. U.S. Pats. 2,560,048,
2560,049 and 2,560,050 (July 10, 1951). (To Firestone).
(C.A., 46:3077; S.C.L., 29:838). Use of sulfur chloride and
a polyalkylcyclohexanol or bis (4,6-di-tert-butyl-3-
methylphenol) sulfoxide or bis phenol sulfoxide.
Cook, W.S., Albert, H.E. Kilbourne, F.L., Jr. and Smith,
G.E.P., Jr. Reclaiming agents for synthetic rubber. Ind.
Eng. Chera, 40: pp. 1194-1202 (1948): repr. in Rubber
Chem. Tech., 22: pp. 166-85 (1949). (C.A., 42:9235;
S.C.L., 25:628; 26:634; R.A., 61:204).
Cook, W.S., and Smith, G.E.P., Jr. Bis (tetraalkylphenol)
monosulfides. U.S. Pat. 2,605,288 (July 29, 1952) (To
Firestone). (C.A., 46:11755; R.A., 30:253). Tetraalkyl
phenol sulfides.
Cook, W.S., and Smith, G.E.P., Jr. Reclaiming natural and
synthetic rubber with bis (tetra-alkylphenol) sulfied. U.S.
Pat. 2,713,561 (July 19, 1955). (To Firestone). (C.A.,
50:4546; R.A., 34:121).
Corkery, F.W. Synthetic rubber reclaimed with a reclaiming
oil. U.S.Pat. 2,449,879 (Sept. 21, 1948). (To Pennsylvania
Industrial Chemical Corp.). (C.A., 42:9237; S.C.L.,
26:880). Composed of crude solvent naptha and a higher
boiling aromatic oil.
Dasher, P.J. Reclaimed rubber. U.S. Pat. 2,304,548 (Dec. 8,
1942). (To Goodrich). (C.A., 37:2960). Heating vulcanized
rubber and hydroxylamine or its salts at a temperature not
lower than 200°F.
Dasher, P.J. Reclaimed rubber. U.S. Pat. 2,304,549 (Dec. 8,
1942). (To Goodrich). (C.A., 37:2960). Heating soft-vul -
canized rubber with any various alkylol amines. Aliphatic
polyamines, hydroxylamines and mercaptoamines at a
temperature not lower than 200° F until the rubber
becomes plastic.
Dasher, P.J., Reclaimed rubber. U.S. Pats. 2,304,550 and
2,304,551 (Dec. 8, 1942) (To Goodrich). (C.A. 37:2960).
By heat treatment with an alipahtic polyamine or an
aliphatic mercaptomne.
Dasher, P.J., Reclaiming vulcanized copolymers of buta -
diene and acrylonitrile, U.S. Pat. 2,465,205 (Mar. 22,
1949). (To Goodrich). (C.A. 43:4510; S.C.L. 27:422).
Acrylic ester.
Dasher, P.J., Reclaiming composite material. U.S. Pat.
2,498,398 (Feb. 21, 1950). (To Goodrich). (C.A. 44:3738;
S.C.L. 28:399). Mineral acid to degrade the cellulosic fiber.
Dasher, P.J., Methods for reclaiming unvulcanized rubber
scrap, or the like; containing fiber, by treatment with
mineral acid vapor. U.S. Pat. 2,701,268 (Feb. 1,1955). (To
Dasher Rubber & Chemical Co.). (C.A. 49:8628; R.A.,
33:344).
Dasher, P.J., Apparatus for reclaiming unvulcanized rubber
scrap, or the like containing fiber. U.S. Pat. 2,927,342
(March 8, 1960). (To Dasher Rubber & Chemical Co.).
(R.A. 38:537; C.A. 54:1829). Scrap subjected to hydro -
chloric acid.
Deutsche, Shell A-G and Metallgeselischaft A-G. Synthetic
rubber. German Pat. 1,077,864 (March 17, 1960). (R.A.
38:350). Synthetic regenerated using oil.
Devulcanizing agents for rubber. Oil, Paint & Drug Reptr.,
141: p. 60 (May 25,1942). An alphabetical list.
DeWaele, A. Plasticizing, reclaiming and reworking vul -
canized rubber. Brit. Pat. 605,588 (1948). (To Gestetner,
Ltd.). (S.C.L., 26:901). Heating in the presence of oxygen
and a poly cyclic secondary amine.
Dinzburg, B.N. Kauch i Rezina, 26, no. 2, Feb. 1967, p.
16-18. The electron microscopic study of vulcanizates
containing phenolformaldehyde resins. The effects are
discussed.
Dogadkin, B.A., Drozdovskii, V.F. Tarasova, Z.N. and
Arkhangelskaya, M.I. Effect of mercaptans and disulfides
on the thermal and thermal oxidative degradation of
swollen vulcanizates. Kauchuk i Rezina, 21 (5); 15-22
(1962); Soviet Rubber Technol, 21 (5): 14-20 (1962).
Drozdovskii, V.F., Dogadkin, B.A. and Sokolov, S.A.
Regeneration of scrap rubber. Russian Pat. 116,024 (Nov.
22, 1958). (R.A., 38:17; C.A., 53:17560). Organic thioyan
- ates.
Drozdovskii, V.F., Sokolov, S.A., and Dogadkin, B.A.
Effect of sulfur containing derivatives of carbazole on the
process of reclaiming rubbers. Kauchuk i Rezina, 18- N<> 4
103
-------
pp. 29-31 (1959); trans in Soviet Rubber Tech., 18: No. 4,
pp. 30-32 1959). (C.A., 53:17560; R.A., 37:588). A time
tread prepared from sodium-butadiene plus natural rubbers
was reclaimed by neutral method using activators.
Drozdovskii, V.F., and Sokolov, S.A. Reclaiming vulcanized
rubber using activators. Russian Pat. 118,172 (Feb. 20,
1959). (C.A., 37:375). This zinc salt of trichorothiophenol.
Drozdovskii, V.F., and Sokolov, S.A. Efficiency of the zinc
salt and disulfide of trichlorothiophenol in reclaiming
rubber by the neutral (water digestion) process. Kauchuk i
Rezina, 18: No.8, pp. 4043 (1959): trans, in Soviet
Rubber Tech., 18: No. 8 pp. 3942 (1959). (R.A, 38:175;
C.A., 54:7208). Tread rubbers were used for this investiga -
tion.
Drozdovskii, V.F., and Shokhin, LA. Method of reclaim of
butyl rubber vulcanizates under the action of radioactive
irradiation. Russian Pat. 128,140 (April 28, 1960). (R.A.,
38:407; C.A., 54:23404). Use of an alkyl phenol disulfide.
Drozdovskii, V.F., Sokolov, S.A. Shokhin, I.A. and Eitin -
gon, I.I. Peptizers for use in reclaiming rubber. Kauchuk i
Rezina, 20 (12): 22-5 (1961): Soviet Rubber Technol. 20
(12); 214 (1961). (C.A., 57:1006: R.A., 41:47). Thio -
phenols are used.
Drozdovskii, V.F., Lavrova, T.V. and Sokolov, S.A. Any -
drides of carboxylic acids and the reclaiming of rubber.
Kauchuk i Rezina 20 (3), 33-5 (1961); Soviet Rubber
Technol. 20 (3), 30-2 (1961). (C.A., 55:25321; R.A.,
40:151). Any drides are less efficient than trichloro -
thiophenol.
Drozdovskii, V.F. Sulfur-containing activators for use in
reclaiming Soviet Rubber Technol. (English Transl.), 21
01): 0962).
Drozdovskii, V.F., Reclaiming Rubber USSR-P 167297
publ. 4:1:65. Catalysts are triphenylphospnine and (or)
B-napthalide of thioglycoltic acid.
Drozdovskii, V.F. Kauch i Rezina 26, no. 5, May 1967, p.
21. Triphenylphosphine trichlorothiophenol and Di (tri -
chlonophenyl) disulphide or vulcanzates. System is effec -
tiveaslowas22°C.
Dubrovin, G.I. Reclaiming rubber wastes and their use.
Kauchuk i Rezina, No. 10: pp. 49-50 (1940). (C.A.
37:4929; S.C.L. 21:299; Chem. Zentr. I; 2046). Treated
with softener and lampblack.
Dufour, R., and Leduc, H.A. Method and apparatus for
heating, in particular for pre-vulcanizing, or reclaiming
rubber mixes or similar materials. German Pat. 948,557
(Aug. 16,1956). (R.A., 35:368). Fillers and additives.
Ecker, R., and Gumlich, W. Regenerating vulcanized rub -
ber. U.S. Pat. 2,338,427 (Jan. 4, 1944). (C.A., 38:4151).
Reclaiming of synthetic rubbers by heating in the presence
of an aromatic mercaptan.
Ecker, R., and Bahr. K. Reclaim of used or scrap rubber.
German Pat. 910,962 (April 1, 1954). (To Farbenfabriken
Bayer, A.-G.). (Addition to German Pat. 898,677). (R.A.,
33:146). Alkali Rhodanides.
Elgin, J.C., and Sverdrup, E.F. Reclaiming scrap vulcanized
material using an olefin as reclaiming agent. U.S. Pats.
2,653,914, 2,653,915 and 2,653,916 (Sept. 29, 1953).
(C.A.,48:395,396; R.A., 32:301). Hexenes, heptenes and
octanes.
Elgin, J.C. Reclaiming rubber. U.S. Pat. 2,593,279 (Apr.
15, 1952). (To U.S. Rubber Reclaiming Co., Inc.) (C.A.,
46:5882; R.A., 30:224). Aliphatic mercaptans and disul -
fides.
Endo, H. Studies of reclaimed rubber. XIV. Effect of
compounding ingredients on reclaimed rubber. 3. Effect of
vegetable oil and fish oil on relcaimed vulcanizates. J. Soc.
Rubber Ind., Japan, 15: pp. 100-17 (1942). (C.A.,
43:2021; S.C.L., 27:511).
Essex, W.G. New development in rubber reclaiming. Trans.
Inst. Rubber Ind. 16: pp. 252-59 (Feb. 1941). Treatment
of standard alkali reclaim with oxygen.
I.G. Farbenindustrie, A.G. Reclaiming vulcanized rubber
articles by nitrochlorobenzene. French Pat. 876,300.
(S.C.L., 23:305; Rev. Gen. Caout., 20:6).
I.G. Farbenindustrie A.-G. Reclaiming vulcanized rubber.
French Pat. 853,577. (C.A., 36:2758; S.C.L. 20:318). By
heating in the presence of oxygen and a monoarylhydra -
zine.
I.G. Farbenindustrie, A.—G. Reclaiming of vulcanizates of
natural and synthetic rubber. French Pat. 876,300 (Nov. 2,
1942). (S.C.L., 23:305; Rev. Gen. Caout., 20-6; Chem.
Zentr. 114: Part II, 1327. Warming with aromatic chloro -
nitro compounds.
I.G. Farbenindustrie A.-G. Reclaiming vulcanized rubber.
German Pat. 708,955 (C.A. 37:3300; S.C.L. 21:238). By
heating in presence of oxygen and monacrylophydrazine.
Farbenindustrie, I.G. Reclaiming of rubber from vulcanized
products. Brit. Pat. 527,417. (S.C.L., 18:845). By heating
in the presence of a monoaryl Hydrazine and oxygen.
I.G. Farbenindustrie, A.-G. Reclaiming vulcanized rubber
products. French Pat. 1,013,958 (Aug. 6, 1952). (R.A.,
31:217; Rev. Gen. Caout, 30:64). Diaryldisulfides contain -
ing nitrated groups.
Flood, D.W., and Mulligan, R.A. Method of and apparatus
for reclaiming latex foam. U.S. Pat. 2,719,830 (Oct. 4,
1955). (To U.S. Rubber). (C.A. 50:3793; R.A. 34:328).
Alkali or borate.
Garvey, B.S. Method of reclaiming rubber. U.S. Pat.
2,193,624 (Mar. 12, 1940) and Can. Pat. 389,891 (July 9,
1940). (To Goodrich). By heating in the presence of a
thiophenol.
104
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Ghez, H. and Ghez, 0. Regeneration of rubber. Brit. Pat.
528,319. (S.C.L., 18:845). Immersing scrap rubber in a
wire mesh receptacle in a bath of hot molten material until
the fabric is carbonized, then withdrawing from the bath,
draining excess liquid off, and cooling rubber.
Ghez, H. and Guez, 0. Caoutchouc regeneration. U.S. Pat.
2,296,275 (Sept. 22, 1942). (C.A. 37:1298). By heatin|in
a liquid bath of bituminous material at 180° to 225°C.
until it can be readily plasticized by milling.
Gibbons, P.A. Process of reclaiming rubber. Canadian Pat.
457,307. In the presence of oxygen.
Green, J. Reaction product of sulfur-vulcanized rubber
polymer and a material having carbon to carbon unsatura -
tion alpha to an electron group. U.S. Pat. 2,879,245 (March
24, 1959). (To U.S. Rubber Reclaiming Co.). (C.A.,
53:14572; R.A., 37:507). The use of maleic anhydride.
Gumlich, W., and Ecker R. Reclaiming rubber. German Pat.
722,575 (May 28, 1942). (C.A., 37:5284). Vulcanized
rubber heated with an aromatic thiol.
Gumlich, W. Reclaiming of rubber. U.S. Pat. 2,280,484
(April 21,1942). (To General Aniline & Film Corp.). (C.A.,
36:6376). Usingthe condensation product of a monarylhy -
drazine and an aldehyde or ketone.
Haang, C.Y. Tanabe H. Nippon Gomm Kyokaiski 40, no. 3,
1967, p. 189 Addition of phenol-formaldehyde resins to
reinforce SBR rubbers.
Haehl, A. Effects of prooxygenic substances on reclaimed
rubber. Rev. Gen. Caout., 21: p. 168 (Aug. 1944); trans in
Rubber Chem. Tech., 19: pp. 123-24 (1946). (C.A.,
39:5541; 40:3928).
Hensley, W.A. Reclaiming rubber with reaction products of
dialkylnaphthols with sulfur chloride. U.S. Pat. 2,647,089
(July 28, 1953). (To Firestone). (C.A., 47:10888; R.A.,
32:214). For vulcanized GR-S or mixtures of natural
rubber and GR-S.
Hermes Patentverwertungs, G.m.b.H. Reclaiming of syn -
thetic rubber. French Pat. 886,587 (Oct. 18, 1943). (Chem.
Zentr., 115: Part I, 1047). Heating with high melting
bitumens.
Higgins, C.J., and Forman, D.B. RR-10-reclaiming agent
and processing aid. (E.I. DuPont de Nemours & Co., Inc.
Rubber Chemicals Div., Report 54-55, Wilmington, Dela -
ware, 1954). (R.A., 33:59). Dixylyl sulfides.
Hudecek, J. and Dlab, J. Method of treating vulcanized
rubber scrap by distillation. Czech. Pat. 96,911 (Oct. 15,
1960); Ref. ZH.Khim., 1962abstr. 14P415. (R.A., 41:58).
Hydrochloric acid is used.
Jaeger, R.W. Rubber reclaiming solvent. U.S. Pat.
2,374,101 (April 17, 1945). (To Standard Oil). (C.A.,
39:4776; S.C.L., 23.306). A specially prepared petroleum
fraction for use as a devulcamzation accelerator.
Johnson, A., and North British Rubber Co., Ltd. Reclaim -
ing of waste rubber. Brit. Pat. 555,643 (Sept. 1, 1943).
(C.A., 39:1080; S.C.L., 21:299). Ground scrap heated with
exhaust gases.
Johnson, T.A., and Thompson, H.H. Reclaiming synthetic
rubber by means of phenyl-beta-naphthylamine. U.S. Pat.
2,478,826 (Aug. 9, 1949) (To Wingfoot Corp.). (S.C.L.,
27:1035).
Johnson, T.A. Reclaiming synthetic rubber. U.S. Pat.
2,478,827 (Aug. 9, 1949) and Canadian Pat. 457,303. (To
Wingfoot Corp.). (C.A., 45:1378; S.C.L., 27:1018). Acidic
aluminum or zinc salt of an inorganic acid.
Johnson, T.A., and Thompson, H.H. Regeneration of
synthetic rubber. U.S. Pats. 2,533,016-7 (Dec. 5, 1950).
(To Wingfoot Corp.) (S.C.L., 29:98) Ethylene glycol.
Joyce, W.J., and Geyer, H.D. Shredding rubber. U.S. Pat.
2,318,693 (May 11, 1943). (C.A., 37:6157; S.C.L.,
21:211). Explosion with ammonia.
Kowaoka, Y. Vulcanization Accelerators. H. Reclaimed
Rubber and Vulcanization Accelerators. J. Soc. Rub. Ind.
Japan, 11: pp. 556-66, 624 (1938). (C.A., 33:2367; S.C.L.,
17:105,304). III. Reaction of Phenylthiourea with Carbon
Bisulfide. IV. New Method for the Snythesis of Mercapto -
benzothiazole from Phenylthiourea and Sulfur. Ibid, 12:
pp. 20-26, 96-102, with abstracts in English on pp. 73-74,
148-50 (1939). (C.A., 33:4077,9045; B.C.A. (B),
408-1939).
Kawashima, Y. Reclaiming rubber. Japanese Pat. 215/1950
(Jan. 30, 1950) (C.A., 46:8890; R.A., 30:509). Milled with
leaves of cryptomeria.
Keilen, J.J. and Dougherty, W.K. Active carbon as anti-stain
agents for reclaimed rubber. (Abstracts only). Rubber Age,
72: p. 73 (1952); Rubber World, 127: p. 87 (1952) (C.A.,
48:1722; R.A., 31:17).
Kelefti, Z., and Wolfner Gyula Estarsa Gumigyar, R.T.
Reclaiming vulcanized rubber. Hungarian Pat. 135,618
(C.A., 44:6192; S.C.L., 28:710). Heated by a bath of an
alloy metal.
Kelly, J.H., Jr. Reclaiming rubbers. U.S. Pat. 2,477,809
(Aug. 2, 1949) (To General Tire). (C.A., 45:2254; S.C.L.,
27:438). Water-insoluble aliphatic amine and a phosphoric
acid.
Kelly, J.H., Jr., Reclaiming elastomers. U.S. Pat. 2,535,931
(Dec. 26, 1950). (To General Tire). (C.A., 43:8196; S.C.L.
29:195). Alkyl phosphates, alkyl phosphoric acids, and
alkyl phosphoric acid salts.
Khodkevich, L. Production of colored reclaim by means of
chemical accelerators of reclaiming. Leka. Prom. 8: No. 5,
pp. 26-27 (1959). (R.A., 38:383). The cost about the same
as black reclaim.
105
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Kilbourne, F.L. Method of reclaiming synthetic rubber.
U.S. Pat. 2,324,980 (July 20,1943). (To Firestone). (C.A.,
38:512). Heating a mixture of rosin, asphalt residue from
cracking crude petroleum solvent naphtha and vulcanized
neoprene.
Kimishima, T. Reclaimed rubber. Japanese Pat. 178,563
(Apr. 16, 1949). (C.A., 45:9910; R.A., 30:99). With
thiophene toluene.
Kirby, W.G. Process of reclaiming rubber. U.S. Pat.
2,276,248 (Mar. 10, 1942) (To U.S. Rubber). (C.A.,
36:4736). Dampening a broken-down fiber-containing
waste rubber stock with ammonium chloride; converting a
semiplastic condition by the combined action of heat, air,
and steam under pressure, with partial disintegration of the
fibers; continuing plasticization of the stock by steam
under pressure; and milling to disperse the fibers uniformly.
Kirby, W.G., and Elliott, P.M. Process of reclaiming water
polychloroprenes. U.S. Pat. 2,343,558 (March 7,1944) and
Can. Pat. 431,501 (Nov. 27, 1945). (To U.S. Rubber).
(C.A., 38:3162). Heating in the presence of an acid of the
formula R-COOH where R is H, OH, COOH or an aliphatic
hydrocarbon group. BP. 566,058.
Kirby, W.G., and Steinle, L.E. Process of reclaiming waste
polychloroprenes U.S. Pat. 2,343,559 (March 7,1944) and
Can. Pat. 431,502 (Nov. 27, 1945). (To U.S. Rubber).
(C.A., 38:3163). Heating in the presence of a sugar. B.P.
563,802 (Dec. 6,1943).
Kirby, W.G. and Steinle, L.E. Process for reclaiming waste
polychloroprenes U.S. Pat. 2,363,873 (Nov. 28, 1944) and
Can. Pat. 428,685 (July 10, 1945). (To U.S. Rubber).
(C.A., 39:3967; S.C.L., 23:58). Heating in the presence of a
di-(hydroxyaryl) sulfide.
Kirby, W.G. and Steinle, L.E. Process of reclaiming waste
polychloroprenes. Can. Pat. 431,500 (Nov. 27, 1945) and
U.S. Pat. 2,391,714 (Dec. 25, 1944) (To U.S. Rubber).
(C.A., 40:1349). Reclaiming scrap polychloroprenes by
mixing in cellulose fibers and heating in the presence of
water at 300° to 420°F. B.P. 557,802.
(1) Kirby, W.G. and Steinle, L.E. Process for reclaim scrap
vulcanized copolymers of 1,3- butadiene and compounds
copolymerizable therewith U.S. Pat. 2,359,122 (Sept. 26,
1944) and Can. Pat. 428,683 (July 10, 1945). (To U.S.
Rubber). (C.A., 39:1780; S.C.L., 22:385). Reclaiming scrap
containing a vulcanized copolymer of 1,3- butadiene and a
compound which contains a single CH2=C (group which
comprises heating in the presence of a d1' '.ydroxyaryl
sulfide.
Kirby, W.G., and Elliott, P.M. Waste polychloroprene
reclaiming process. Can. Pat. 431,499 (Nov. 27, 1945). (To
U.S. Rubber). Heating in a comminuted condition in the
presence of water at 300° to 420° F in the presence of an
amide.
Kirby, W.G. and Steinle, L.E. Process for reclaiming scrap
vulcanized rubber. U.S. Pat. 2,372,584 (March 27, 1945)
and Can. Pat. 428,684 (July 10, 1945). (To U.S. Rubber).
(C.A., 39:3462; S.C.L., 23:235). Heating at 300° to 420°F.
the scrap in which has been incorporated a small amount of
a di-(hydroxvaryl) sulfide.
Kobrinskii, L.S. Method of reclaim of high polymers from
fabric containing secondary raw materials. USSR Pat.
139,819 (Aug. 5, 1961). Ref. Zh. Khim., 1962 (13): Abstr.
13P125. The polymer containing fabric of cellulosic fibers,
is comminuted and placed in a drum provided with heating
devices, treated with hydrogen chloride for 1 to 2 h at 120°
to 130°C and then neutralized with ammonium vapor at 80
to 100° for 15 to20min.
Krivunchenko, N.G. Kolkhir, K.F. Zvereva, N.I. Dmitrieva.
E.V. Drugovskaya, M.N. and Sokolov, S.A. Gas tars in
reclaiming rubber. Kauchuk i Rezina. 21 (1): 52-3 (1962)
(R.A., 41:67).
Krivunchenko, N.G., Kolkhir, K.F., Zvereva, N.I. Dmitri -
eva, E.V. and Sokolov, S.A. Reclaim of rubber. U.S.S.R.
Pat. 138,022 (May 10, 1961); Byul. Ixobret. 1961 (9),
42-3. (R.A., 39:436). Gas Generator Resin.
Kuznetson, V.I., Govorova, RP., Kivyi, G.V., and Landa,
IM. Use of the furfurol extract of the ligroin-petroleum
fraction of primary lignite tar for rubber reclaiming.
Ukrain. Khim, Shur, 21: pp. 12731 (1955) (C.A.,
49:16496; R.A. 34:61). Lignite tar.
Lambrino, V. Norsene, M. and Verodi, F. Reclaiming of
used rubber by means of D.T. plasticizer with swelling
properties. Ind. Usoara (Bucharest), 5: pp. 56-59 (1958).
(R.A., 36:258). A new plasticizer containing maphthenic,
paraffinic, aromatic and unsaturated hydrocarbons.
LeBeau, D.S. U.S.P. 3, 184, 422 (1965) Retardation of
Mooney growth with 3 parts of Sodium Nitrite.
LeBeau, D.S. Reclaiming agents for natural and synthetic
rubber. I. Solvent naptha. R.A. (N.Y.), 68: pp. 49-56
(1950). (C.A., 45:1372; S.C.L., 28:398,966).
LeBeau, R.V. Reclaiming synthetic rubber with (1) an
amine and (2) a fatty acid and live steam. U.S. Pats.
2,423,032 and 2,423,033 (June 24, 1947). (C.A., 41:6074;
S.C.L., 25:699).
Levin, M. Method of making rubber mixtures and resulting
product U.S. Pat. 2,261,166 (Nov. 4, 1941). Heating
fiber-containing scrap with a small proportion of a mild
alkali.
i
Lewis, J.R. Reclamation of rubber in the presence of a,
a-di-alkylarylmethyl hydroperoxide. U.S. Pat. 2,558,764
(July 10, 1951). (To Hercules Powder Co.). (S.C.L.,
29:765).
Liverovskn, A.A., Shrulevskaya, E.I. and Sokolov, S.A.
Substitutes for crude pine resin in the reclaiming industry.
Zhur. Priklad, Khim., 30: pp. 183743 (1957). (C.A.,
52:10628; R.A., 36:454). Rosin obtained from pine
stumps.
106
-------
Lorand, E.J. and Reese, J.E. Oxidation of aromatic
hydrocarbons U.S. Pat. 2,548,435 (Apr. 10, 1951). (To
Hercules Powder Co.). (C.A., 45:8555; S.C.L., 29:1009).
Useful in rubber reclaiming.
Mankowich, I. Reclaiming of vulcanized scrap rubber. U.S.
Pat. 2,871,205 (Jan. 27,1959). (To U.S. Rubber). Treating
with formaldehyde.
Mankowich, I., Steinle, L.E. and Chiavetta, F.P.U.S. Pat.
2,871,206 (Jan. 27, 1959). (C.A. 58:10828; R.A. 37:375).
(To U.S. Rubber) Adding aldehyde to the reactants in the
heater process.
Metallgesllschaft, A.-G. Treatment and regeneration of
rubber hydrocarbons. French patent 877,891. (S.C.L.,
23:463; Rev. Gen. Caout., 20:20) By-products of acid tars
used.
Mersereau, J.M. Mester P.J. USP 3267067 Retardation of
Mooney growth by the addition of benzyl mercaptan.
Midland Silicones, Ltd. Reclaiming siloxane elastomers Brit.
Pat. 752,860 (July 18, 1956). (R.A., 34:502). Anhydrous
hydrogen chloride.
Mishustin, I.U., and Pisarenko, A.P. Influence of softening
agents on the reclaiming of soiling waste. Kauchuk i Rezina,
No. 1: pp. 4243 (1941). (C.A., 37:5621; Chem. Zentr.,
113.-Part II, 1064).
Montecatini Soc. Gen. FP. 1429092 Regeneration of
Elastomers based saturated vulcanized olefin copolymers.
Polymers heated to 175-225°C, 2-10 hours.
Moore, D.V., and Thompson, H.H. Reclaiming method.
Can. Pat. 429,743 (Aug. 28,1945) and U.S. Pat. 2,386,707
(Oct. 9, 1945). (To Wingfoot Corp.). (C.A., 39:512;
40:763). Reclaiming a cured butadiene copolymer with
styrene or acrylonitirile by heating with a swelling agent
which contains ethyl alcohol as a plasticizer.
Morche K. Ehrend H. Rev. Gen. Caout Plast., 43, no. 9
Sept. 66 p. 1111-15. Use of factice in ethylene propylene
terpolymers.
Naftolen Gesellschaft zur Veruwertung der Rostler-
Mener'schen Verfahren, MbH. Regeneration of vulcanized
rubber. Netherlands Pat. 55,743. (S.C.L., 23:235; Rev.
Gen. Caout., 21:26). Heating between 160° and 380°C.,
under a pressure of 12 mm. of mercury in the presence of
resinous substances or of oils, soluble to at least 30% in
concentrated sulfuric acid.
Naphthenic acids in the rubber industry. Rev. Gen. Caout.,
p. vi. Supplt., June 1936, (S.C.L., 14:591).
Naudain, E.A., and Boys, C.H. Pan process of reclaiming
rubber U.S. Pat. 2,794,006 (May 28, 1957). (To Hercules
Powder Co.). (C.A., 51:12534; R.A., 36:15). Petroleum
hydrocarbon-insoluble pine wood resin.
Neal, A.M., and Schaeffer, J.R. Devulcanizing Rubber. U.S.
Pat. 2,333,810 (Nov. 9, 1943). (To DuPont). Subjection
whole-tire scrap separately to the action of a thiophenol
and to dilute aqueous sodium hydroxide. Can. pat.
423,928.
Nicholaisen, B.H. Vulcanized rubber reclaiming composi -
tion of sulfurized tall oil and napthernic base petroleum oil.
U.S. Pat. 3,008,906 (Nov. 14, 1961). (To O. Mathieson
Chem. Corp.) (C.A., 56:6144: R.A., 40:298).
Nikolaev, N.V. Mikhailov, N.I. and Yastrebov, T.G. Soften -
er for regeneration of rubber. Russian Pat. 105,203 (March
25,1957). (C.A., 51:10111;R.A., 35:475).
Oblocynzsky, J. Reclaiming vulcanized synthetic rubber
waste. French Pat. 931,885. (S.C.L., 27:686; Rev. Gen.
Caout, 26:531). Pretreating with paraffin oil.
Oils used in reclaiming rubber. Oil, Paint & Drug Reptr.,
142: No. 15, p. 44 (Oct. 12,1942).
Osipovsky, B.Y., Khutoretskaya, S.N., Borscheveskaya,
V.A. and Khrenkov, I.I. Rubber reclaiming process. Russian
Pat. 58,383 (S.C.L., 23:306; Rev. Gen. Caout., 20:6). Using
a fraction of tar oil as solvent.
Osipovskii, B. Ya., Knutoretzkaya, S.N. Borschchevskaya,
V. A. and Khrenkov, I.I. Reclaiming rubber. Russian Pat.
58,836. (C.A., 39:1080; S.C.L., 20:215; Chem. Zentr.,
112:11,824). Use of boiling tar oil.
Patel M.U. Rubber News, 6, no. 10, July 67, p. 22. Resins
in the Rubber Industry. Resins, their makers their effects
on rubber properties structures etc are discussed.
Pearson, W.L., and Schweller, H.E. Reclaiming of uncured
and uncompounded latex foam stock. U.S. Pat. 2,925,396
(Feb. 16, 1960). (To General Motors). (R.A., 38:431 ;C.A.,
54:11534). Use of mineral acid.
Phoenix Gummiwerke AG GP 1233132 Vulcanized Rubber
Waste. Pretreated with diazonium salt. Azo dyes form
which do not migrate to give non stain reclaim.
Polyplast Gesellschaft Fur Kautschukchemi. Platiciation of
rubber waste. German Pat. 1,000,598 (Jan. 10, 1967).
(R.A., 38:221; C.A., 53:23048). Use of tnethylamine
oleate.
Polyplast Gesellschaft Fur Kautschukchemi m.b.H. Regen -
eration of scrap rubber. Brit. Pat. 761,478 (Nov. 14, 1956).
(R.A., 35:114). Balata and gutta-percha is reclaimed by
mixing with an oxidized extract of a mineral lubricating oil.
Proell, W.A. Thiosulfenyl chlorides and bromides, and
polymers made therefrom, U.S. pat. 2,684,952 (July 27,
1954). (To Standard Oil Co.). (R.A., 33:73). Polysulfide
rubbers reclaimed by reacting with chlorine.
Radinger, E.J. Treatment of reclaimed rubber. Brit. Pat.
712,827 (Aug. 4, 1954). (To Thames Industries, Ltd.).
107
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(R.A., 32:491). Addition of ammonia to emulsions of
reclaim.
Randall, R.L. Reclaiming scrap. U.S. Pats. 2,545,828 and
2,471,496 (March 20, 1951). (To Midwest Rubber Reclaim
- ing Co.). (C.A., 43:6438; S.C.L, 29:488) Gray Tower
resin oil.
Ray, P.A. Treatment of rubber. Brit. Pat. 546,797 (July 30,
1942). (To Hercules Powder). (C.A., 37:4930; S.C.L.
20:347). With a softener comprising a blend of an oily
product from destruction distillation of pine-wood resin
and the residue of such distillation.
Reagents used in manufacture of vulcanizing agents; sol -
vents for reclaiming vulcanized rubber scrap; solvents,
general, for rubber. Oil, Paint & Drug. Reptr., 142: No. 3,
p. 44 (July 20,1942). Alphabetical lists.
Rebmann, A. Regeneration of aged rubber. Swiss Pat.
215,952 (Nov. 1, 1944) (C.A. 42:4390; S.C.L. 23:235;
Rev. Gen. Caout., 21:26). Treating under pressure with
benzene substitution products containing thiophenol, and
washing thereafter with water, oil or glycerin.
Regie Nationale Des Usines Renault. Utilizing reclaimed
rubber. French Pat. 952,734. (C.A., 45:5446; S.C.L.,
28:303; Rev. Gen. Caout., 27:175); Lead salt of a
derivative of dithiocarbamic acid.
Reich, HFH Increasing the output of comminuting ma -
chines for viscous and elastic scrap material. German Pat.
892,676 (Aug. 27, 1953). (To Gebruder Eirich). (R.A.,
32:268). Material treated first with a swelling agent.
Rennemann, H., and Gunzert, T. Reclaiming vulcanized
synthetic rubber scrap. German Pat. 716,151 (Dec. 11,
1941). (C.A., 38:2524). Using a softener which is a
combination of three softeners, E.G., tetrahydronaph -
thalene, coumarone resin, and wool fat.
Rhein-Chemi GmbH. Waste vulcanized rubber. Ger. Pat.
1,123,102 (Feb. 1, 1926; Ger. Pat. Abstr. 2 (9), 1 (1962)
(C.A., 56:14447; R.A., 40:236). Comminuted waste is
mixed with salts or heavy metal salts of fatty acids or
mixtures of such salts, and the mixture is heated above
100°C.
Rivier, A., and Dietzel, E. Working-up scrap rubber.
German Pat. 8395 (Oct. 11,1954). (To Deutsches Hydrier -
werk Rodleben, V.E.B.) (R.A., 34:62) Working-up is
carried out with swelling agents.
Rostler, K.S., and White, RM. Swelling of rubber. I. Study
of aromatic hydrocarbon reclaiming oils with regard to
swelling action of GR-S and natural rubber. R.A. (N.Y.),
58: pp. 585-90 (1946). (C.A., 40:2671; S.C.L., 24:257).
Rubber Reclaiming Co. B.P. 1009592. Recovery of nylon
from tyre scrap. Using 60-75% aqueous formic acid.
Sakada, M. Reclaimed rubber. Japanese Pat. 176,629 (Aug.
31, 1948). (C.A. 45:4962; S.C.L., 29:661). With furfural.
Sanyou Yushi Kogyo Co. and Teikoku Kasei Co. Process
for the treatment of reclaimed rubber. Japan Pat. 15,381
(1961). (R.A., 40:293). A non-ionic surface activator is
used.
Sarada, M. Regenerated rubber. Japanese Pat. 177,783
(Feb. 15, 1949). (C.A., 45:9910; 30:110). Mixed with
waste liquor from sulfite pulp.
Sartorelli, U. Reclaiming vulcanized rubber. East German
Pat. 509 (Nov. 30, 1953) (To Pirelli Societa per Azioni).
(R.A., 33:430). Aliphatic alcohols.
Satake, S., and Tatebayashi, K. Regeneration of vulcanized
rubber scrap. Japanese Pat. 3746/1950 (Oct. 27, 1950). (To
Furukawa-Industries Co.). (C.A., 46:10677-78; R.A.,
31:67). Dibenzyl Ether.
Saul, W., and Wiggins, T.J. Reclaiming of rubber. Brit. Pat.
744,917 (Feb. 15, 1956). (To Semtex, Ltd.). (R.A.,
34:236). Polyglycol esters of monobasic organic acids.
Schneider, P. Mastication and reclaiming with chemical
agents. (Abstracts only). Kautschuk and Gummi, 4: p. 407
(1951); Gummi u. Asbest. 4: p 392 (1951). (R.A., 30:68).
Aromatic mercaptans and disulfides.
Schwerdetel, F. Reclaiming vulcanized rubber. German Pat.
737,948 (July 1, 1949) (To W.G. Farbenindustrie). (C.A.,
39:4150). By subjecting scrap to an oxidizing treatment in
the presence of a chloronitrobenzene.
Semperit Gummiwerk G.P. 1218715 Reclaimed Rubber.
Pretreat rubber with aldehydes in presence of dil H2 SO4.
This type can be used in contact with white or light-colored
PVC without discoloration.
Shokhin, I.A., and Belostotskaya, G.I. Molecular structure
of the rubber in reclaim. Trudy Nauch. Issledovatel. Inst.
Resin. Prom., No. 2 pp. 13645 (1955). (R.A., 34:533).
Trichlorothiophenol is a good activator.
Smith, G.E.P., Jr., and Ambelang, J.C. Reclaimed rubber.
U.S. Pat. 2,495,145 (Jan. 17, 1950). (To Firestone). (C.A.,
44:3293; S.C.L., 28:370). With reaction product of sulfur
dichloride and a phenol.
Smith, G.E.P., Jr. and Bennett, R.B. Reclaiming rubbers.
U.S. Pat. 2,686,163 (Aug. 10,1954). (To Firestone). (R.A.,
33:73). Aliphatic amines.
Smith, G.E.P., Jr. Reclaiming rubbers. U.S. Pat. 2,626,932
(Jan. 27, 1953). (To Firestone). (C.A., 47:4642; R.A.,
31:306). Sulfide of a petroleum cresylic acid.
Sokolov, S.A., and Drozdovskii, V.F. Influence of the
composition of pine tars of reclaiming tire stock from
natural and synthetic rubber. Kauchuk i Rezina, 16: No. 9,
pp. 12-15 (1957). (C.A., 52:10627; R.A., 36:160). Pine
tars as softeners for rubber reclaim.
Sparks, W.J. and Baldeshwieler, E.L. Recovery of isoolefin
polymers. U.S. Pat. 2,343,816 (March 7, 1944). (To Jasco,
108
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Inc.) (C.A., 38:3395). Isolating pure isobutylene polymers
from a vulcanized composition with natural rubber by
extracting with naptha hydrocarbons.
Spcoete, A. Wolber, Reclaiming synthetic rubber. French
Pat. 925,088 (1948). (S.C.L., 26:900; Rev. Gen. Caout.,
25:94). Reduced to dust and treated with coal tar
anthracene oil or coumarone resins.
Stafford, W.E., Mellor, G. and Armstead, B.H. Soluble zinc
sulfide in reclaim. Rubber Plastics Weekly 141 (4), 119-20
(1961). (R.A., 39:485).
Standard Oil Co. of N.J. Petroleum Products for Rubber
(Technical Bulletin). R.A. (N.Y., 45: p. 31 (Apr., 1939);
I.R.W., 100: No. 2, p. 63 (May, 1939).
Staten, F.W., and Haines, W.M., Jr. Reclaiming mixed
vulcanizates of natural and synthetic polymers. U.S. Pat.
2,522,069 (Sept. 12, 1950). (To Gates Rubber Co.). (C.A.,
45:384; S.C.L., 28:890). With multivalent catalyst.
Studio Chmico Industriale, Depolymerication of vulcanized
rubber. Italian Pat. 451,123 (Aug. 27, 1949). (Also Italian
Pat. 431,570). (C.A., 43:8734; 45:896; S.C.L., 29:386).
Napthalene.
Sugimoto, S. Minamikata, I., and Sakai, K. Studies of
reclaimed rubber. I. Alkali-reclaimed rubber. Repts. Imp.
Ind. Research Inst., Osaka, Japan 20: No. 10,41 pp. (1940).
(C.A., 35:929). III. Oil reclaimed rubber. Ibid, 21: No. 5,
28 pp. (1940). (C.A., 35:929. Use soybean oil.
Sugino, K. Softeners for miscellaneous types of reclaim. J.
Soc. Rubber Ind. Japan, 16: pp. 79-90 (1943). (C.A.,
43:8191;S.C.L., 28:51).
Sverdrup, E.F. Reclaiming vulcanized rubber in the pres -
ence of unvulcanized high styrene polymeric material U.S.
Pat. 2,845,395 (July 29, 1958). (To U.S. Rubber Reclaim -
ing Co.). (C.A., 52:19230; R.A., 37:66). Natural GR-S,
nitrile and butyl rubber can be reclaimed.
Sverdrup, E.F. Reclaiming rubber. Brit. Pat. 675,595 (July
16, 1952. (To U.S. Rubber Reclaiming Co., Inc.). (R.A.,
30:416). A compound with the thiophene ring.
Sverdrup, E.F. Reclaiming rubber with thiophene com -
pound. U.S. Pat. 2,494,593 (Jan. 17. 1950). (To U.S.
Rubber Reclaiming). (C.A., 44:3737; S.C.L., 28:268).
Swellers for rubber in reclaiming processes. Oil, Paint &
Drug Reptr., 142: No. 16, p. 71 I Oct. 19, 1942).
Alphabetical list.
Syui-Chzhou, Li. Comparative study of the use of pine resin
and hemp seed oil for the preparation of reclaim for shoe
soiling. Khuasyue Shintsze, No. 12, pp. 540-42 (1957).
(R.A., 37:66). Hemp seed oil.
Tewksbury, L.B. Jr., and Howland L.H. Reclaiming with
hydrocarbon disulfide. U.S. Pat. 2,469,529 (May 10, 1949)
and British Pat. 622,576 (To U.S. Rubber) C.A., 43:5992;
S.C.L., 27:603).
Thompson, H.H. Depigmentizing reclaimed rubber. U.S.
Pat. 2,365,662 (Dec. 26, 1944). (To Wingfoot Corp.). (C.A.
39:3968; S.C.L., 23:150). Mixing bententie with the stock
and the extracting with a rubber solvent while the benton
inhibits removal of the carbon black by the solvent.
Treves, A. Process of reclaiming rubber waste materials.
U.S. Pat. 2,325,289 (July 27, 1932). (C.A., 38:660).
Heating ground rubber scrap and 1 to 5% of abietic acid or
sylvic acid in the absence of water or steam for 30 minutes
at 100-140°C.
Treves, A. Process for the treatment of rubber waste. U.S.
Pat. 2,352,460 (June 27, 1944). (C.A. 38:5692; S.C.L.,
22:303). Rubber reclaim which is soluble in rubber solvents
by treatment of ground vulcanized scrap with abietic acid
or sylvic acid.
Treves, A. Treatment of rubber and particularly rubber
waste materials. Brit. Pat. 551,461 (Feb. 24, 1943). (C.A.,
38:2850; S.C.L., 21:112). Mixing not more than 10% of
abietic acid or abietic acid-containing substances or cou -
marone resin into ground scrap and heating for 1 to 2 hours
only at a temperature not exceeding 180°C.
Tsi-Te, Ku, Investigation of the use of pine tar resin in the
reclaim of synthetic and natural rubber. Hsiang-Tsiao, No.
6, pp. 15-21 (1959) (R.A., 38:520).
Tsvetaeva E.M. New Reclaiming Agents based on chemi -
cally treated shale Sov. Rbb. Tech. vol. 25, no. 9, p 42
(1966) Phenolic pitch has a reinforcing effect on reclaim.
Tsvetaeva, E.M. Methods of synthesis and modification of
softeners for reclaiming vulc. anisates. Vol. 24 No. 11 Page
19 Nov. 1965 Len. 4 Lang Rus. Kauchuk, I. Rezina.
Tsvetaeva, E.M. Role of softeners in the reclaiming of
vulcanizates from SK-B. Legkaya Prom., No. 6: pp. 25-26
(1944). (C.A., 39:4515). Softeners must act as swelling
agents and penetrants, have high adhesive properties, and be
capable of further polymerization or vulcanization: those
having multiple unsaturated bonds in the same carbon
chain, i.e., highly unsaturated aliphatic acid derivatives.
Tsvetaeva, E.M. Kauch i Rezina 26, no. 6, June 1967, p 37.
Reclaiming of SKD vulcanizates (Stereoregular butadiene
rubber) reclaimed with fatty acid, plasticizer and shale-oil.
Tsvetaeva, E.M. Glushnev V.E. Method of Synthesis and
Modification of Softeners for Reclaiming Vulcanizates. Sov.
Rubb Tech. vol.24, no. 11, p 200 (1965).
Tsvetaeva, E.M. Reclaiming of vulcanized rubber. Russian
Pat. 125,380 (Jan. 8, 1960). (R.A., 38:327; C.A.,
54:12640). Propane and hexane used.
Utanol - A. Semi-Softening Agent, R.A. (N.Y.) 43: p. 228
(July 1938). S.C.L., 16:810).
109
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Van Valkenburgh, E.A. Liquid for reclaiming rubber. U.S.
Pat. 2,736,662 (Feb. 28, 1956). (C.A, 50:8243; R.A.,
34:433). Tall oil.
Van Valkenburgh, E.A. Reclaiming oil composition and
method of making it. U.S. Pat. 2,908,676 (Oct. 13, 1959).
(R.A., 38:221 ;C.A., 54:1915). Relates to Bunac KS.
Van Valkenburgh, E.A. Solvent for reclaiming vulcanized
rubber. U.S. Pat. 2,714,071 (July 26, 1955). (C.A.,
50:4548; R.A., 34:108). Diethylene Triamine.
Vinitskii, L.E., and Litovchenko, M.P. Thermal reclaiming
of natural rubber in the presence of activators. Trudy
vseros, Nauchoissled. Khim. Inst. Prom. Mestn. Poschinen -
iyz, No. 6, pp. 45-52 (1958). R.A., 37:482). Trich'oroph -
enol.
Warren, S.F., and U.S. Rubber Reclaiming Co., Inc.
Reclaiming natural and synthetic rubber. British Pat.
610,901 (S.C.L., 27:158). Organic disulfide.
Warren, S.F. Reclaiming rubber. Brit. Pat. 657,637 (Sept.
26, 1951). (To U.S. Rubber reclaiming Co., Inc.) (R.A.,
30:13). Tertiary lauryl mercaptan.
Webb, E.J., Cook, W.S., Albert, H.E., and Smith G.E.P., Jr.
Arylamide sulfide cayalysts in reclaiming GR-S vulcan -
izates, Ind. Eng. Chem., 46: pp. 1711-15 (1954). (C.A.,
48:14281; R.A., 32:510).
Westhead, J. Fillers for reclaim stocks. Trans. Inst. Rubber
Ind, 17: pp. 249-54 (Feb. 1942). (C.A, 36:5675). Dis -
cusses effect of pigments.
Wheeler, G.P. Reclaimed rubber and method of making
same. U.S. Pat. 2,433,179 (Dec. 23,1947). (To Goodrich).
(C.A , 42:2468;S.C.L, 26:213). An aryl selenide used.
White, C.M. Oxidized tall oil and petroleum oil composition
method of making and method of reclaiming rubber. U.S.
Pat. 3,043,786 (July 10, 1962). (C.A., 57:10015; R.A.,
41:107). A small amount (0.5 to 2.5% by weight) of tall oil
oxidized as described is added to rubber being leclaimed,
An example describes the reclamation of SBR.
White R.A. USP 3210301 Process of Reclaiming Rubber
wherein Atactic Polypropylene is added.
Wingfoot Corp, Reclaiming synthetics. Brit. Pat. 558,334
(Dec. 31, 1943). (C.A, 39:3966; I.R.J, 106:381). By
treating hot with a swelling agent, and incorporating a
carboxylic acid or a monohydric aliphatic alcohol into the
swollen material.
Wingfoot Corp. Regenerating copolymers. British Pat.
615,865. (C.A, 45:1378;S.C.L. 27:324). Mix rubber with
coal tar distillate and heat.
Yaroslay, C. Reclaiming of synthetics from polymers of
butadiene and the alkyl or halogen drivatives of rubber.
German Pat. 743,605 (Dec. 29,1943). (Chem. Zentr. 115:
Part I, 1047). By treating under heat and pressure with
compounds containing dithiocarbomic acid derivatives,
thiazole, thiuram sulfide, thiazoyl disulfide or benzo-
thiazoyl disulfide.
Zachesova, G.N. Yablonskya, F.A. Kauch i Rezina, 26, no.
8 Aug. 67 p. 39 Wood chemistry products as emulsifiers in
the reclaiming of rubbers by the dispersion method. Rosins
and tall oil emulsifiers are evaluated.
Zaionchkovskii, A.D, and Livyi, G.V. Destruction of
rubber materials in reclaim manufacture. Legkaya Prom.,
No. 9, p. 34 (1955). (C.A, 50:5322; R.A. 34:279).
Destruction is accelerated by oxidants.
Refining/Finishing Equipment
Baratteri, A. Apparatus for refining reclaimed rubber.
Italian Pat. 393,128 (Kautschuk, P. 70, Oct.-Nov. 1943).
Brown, G.L, and Johnson, T.A. Finishing reclaimed rub -
ber. Brit. Pat. 703,087 (Jan. 27, 1954) and U.S. Pat.
2,645,817 (July 21, 1953). (To Wingfoot Corp.). (R.A,
32:199). Final plasticization and sheeting steps.
Campbell, C.H. Refining reclaimed rubber with cooling of
the rubber to facilitate separation of tailings. U.S. Pat.
2,471,392 (May 24,1949). (S.C.L, 27:689).
Campbell, C.H. Refining of reclaimed rubber. U.S. Pat.
2,524,375 (Oct. 3,1950). (S.C.L, 28:965).
Gordinskii, B.Y, Shimanskii, V.M, Gaevskii, A.F, Shkol -
nik, S.I. Reworking of polyester urethane Plasticheskie
Massy Vol. No. 9 Page 65 Sept. 1965 Len. 2 Lang. Rus.
Hayakawa Rubber Co. Apparatus for automatically refining
desulfurized reclaim rubber. Japanese Pat. 6,441, (1959).
(R.A, 38:112).
Jarvis, E.A, Refining scrap plastic and apparatus therefor.
U.S. Pat. 2,879,005 (March 24, 1959). (To M. Sobel).
(C.A, 53:1184; R.A. 37:504). PVC, polyethylene, and
SBR.
Rivier, A. and Dietzel, E. Working-up of scrap rubber.
German Pat. 8395 (Oct. 11, 1954). (To Deutsches Hydrier -
werk Rodleben V.E.B.) (R.A, 34:62) Working-up is carried
out with swelling agents.
Retreaders
Braner, H.H, An Analysis of the Domestic Retreading
Industry, Ranno Printing Co, Englewood, N.J, Lib. Con -
gress#65-5620.
Corey, E.R. Industrial Marketing; Cases and Concepts.
Englewood Cliffs, N.J.: Prentice Hall, Inc. 1962.
Schidrowitz, P, and Dawson, T. (eds.) History of the
Rubber Industry, Cambridge: W. Heffer & Sons Ltd, 1952.
110
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Articles and Periodicals
"Cheap Materials Can Damage Reputation of Retread
Business," NTDRA Dealer News, XXVII, No. 40, p. 2.
(Edwards, George). "Adjustment Costs, Policies and Objec -
lives," Retreaders Journal (September, 1962), p. 7.
(Edwards, George). "Adjustment Policies," Retreaders
Journal (August, 1962), p. 14.
"Inconsistency is Causing Tread Separations," Retreaders
Journal (June, 1963), P. 18.
"New SBA Guarantee on Equipment Financing May Boost
Retreading," Retreaders Journal (May, 1964), p. 3.
"H.R. 10712 - Federal Legislation," NTDRA Dealer News,
XXVII, No. 15 (April 20,1964), p. 2.
"How Retreaders Advertise," Retreadweek, II, No. 1
(April, 1963), p. 15.
"Interesting Facts About Retreaders," Retreadweek, III,
No. 1, (April, 1964) p. 57.
Janicki, E. "Automakers Comment on Tire Standards,"
NTDRA Dealer News, XXVII, No. 17 (April 27, 1964), p.
5.
Murphy, J.S. "Jet to Spark Room in Treading," Tires and
TBA Merchandising (August, 1957), p. 29.
"Quality is Avenue to Take," Retreadweek, II, No. 1
(April, 1963), p. 34.
"Quality Merchandising of Quality Retreads," NTDRA
Dealer News, XXVI, No. 46 (November 11, 1963), p. 8ff.
"Recapper Profits from Quality Market," Tires and TBA
Merchandising (November, 1961), p. 32.
Baylor, Ivan. "Economy Tires Dim Your Profit Picture,"
Modern Tire Dealer (November, 1962), p. 53.
"Tire Inspection Rules, Regulations Passed," NTDRA
Dealer News, XXVII, No. 34 (August 24, 1964), p. 3.
Reports and Surveys
Crowell-Collier Automotive Survey. An Annual Survey
Performed by Crowell-Collier Publishing Co., New York,
N.Y.
Look National Automobile and Tire Survey. An Annual
Survey Performed by Cowles Magazine and Broadcasting
Co., New York, N.Y.
National Tire Dealers and Retreaders Association, Estimates
of Tire Replacement Shipments by Channels of Distribu -
tion and Tire Types: 1957-1962 (By Dr. Warren Leigh),
Washington, D.C., 1963.
NTDRA Merchandising and Advertising Catalogue, Wash-
ington, D.C., 1962.
Repair and Retreading Service for Off-the-Round Tires:
National Directory, Washington, D.C., 1962.
Retread Shop Operating Manual, Washington, D.C., 1962.
Newsweek Passenger Tire Census. Annual Survey performed
by Newsweek, Inc., New York, N.Y.
Newsweek Truck Tire Census. An Annual Survey per -
formed by Newsweek Inc., New York, N.Y.
Rubber Manufacture Association. RMA Recommended
Minimum Standards for New Passenger Car Tires, New
York, 1964.
Rubber Highlights, New York, N.Y. (Monthly).
Special Survey of Tire Production Capacity, New York,
N.Y. 1963.
Tire Retreading Institute (Division of National Tire Dealers
and Retreaders Association). National Standards for Tread -
ing Automobile and Truck Tires. Washington, D.C., 1959.
Sales Pamphlets and Literature
An Analysis of the Automotive Market, New York: Tire,
Battery and Accessory News, 1958.
Retreading Equipment: Catalogue No. 1, Lodi, Calif.:
Super Mold Corporation, 1962-1963.
Rubber in Roads
Accumulatoven-Fabrik, A.G.,
Reclaim, French Pat. 876-353; (Rev. Gen. Caout., 20:6)
Immersing Scrap rubber in hot bitumen at 230°-250° for
a period between 15 to 30 minutes in the absence of air.
Reclaimed Rubber, Ital. Patent 393,309. Dipping in hot
Bitumen.
Allison, K.
Those Amazing Rubber Roads, Rubber World, pp. 47-52
March 1967.
Those Amazing Rubber Roads, Part II Rubber World,
pp. 91-106, April 1967.
Andeyeri, J.B.,
Schiffman, R.L.
Pavement Design Methods - Literature Review, Bureau
of Public Roads, March 1965 (480 References)
111
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The Asphalt Institute
Asphalt Membranes and Expansive Soils, The Asphalt
Institute Information Series, No. 145, May 1968.
Benson, J.R.
The Reology of Rubberized Asphalts Annual Meeting
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Bata, A.S. Regeneration of synthetic rubber. French Pat.
885,895 (Sept. 28, 1943). (Chem. Zentr., 115; No. 1,
114041). Heating butadiene or chloroprene rubber with
dithiocarbamic acid derivatives, thiazole, thiazyl sulfide,
thiuram sulfide or debenzothiazyl disulfide.
Bata, A.S. Regeneration of natural or synthetic rubber.
French Pat. 885,896 (Sept 28, 1943). (Chem. Sentr., 115,
No. I, 1047). Treatment of vulcanized rubber, chloroprene,
buna or butadiene rubber with organic sylfonyl chlorides
under heat and pressure.
Bata Narodni Podnik. Regenerating vulcanized rubberlike
polymers of chloroprene. Netherlands Pat. 67,287 (Jan. 16,
1951). (S.C.L. 29:265).
Beaver, D.J. Oil-resistant thermoplastic and method of
making. U.S. Pat. 2,382,462 (Aug. 14, 1945). (To Mon -
santo Chemical). (C.A., 39:5547) Intimately mixing scrap
rubber or reclaimed rubber with polyldichlorphosphine and
retane and heating.
Bina, J. and Cernuska, 0. Reclaim from silicone rubber.
Chem. Prumysl. 13 (2): 112 (1963). (R.A., 42:253).
Brown, G.L., Johnson, T.A., and Knill, R.B. Non-discolor -
ing reclaim U.S. Pat. 2,640,035 (May 26, 1953). (To
Wingfoot Corp.). (C.A., 47: 7814; R.A., 32:57). Devul -
canizing with a light colored rosin oil.
Campbell, C.H., Oil-resin reclaiming blend. U.S. Pat,
2,468,482 (Apr. 26, 1949). (S.C.L., 27:603).
Castello, A.D. Peptized vulcanizate and method of pre -
paring it U.S. Pat. 2,211,592 (Aug. 13, 1940). (To
Goodrich). Reclaiming well-vulcanized soft rubber by add -
ing an organic material to accelerate the vulcanization and
masticating below 180°F.
Castello, A.D., and Dixon, H.L. Reclaimed rubber. U.S. Pat.
2,278,826 (Apr. 7, 1942) (To Goodrich). (C.A., 36:6376)
Preparing a nonstaining composition by admixing vul -
canized rubber, an absorbent material, and a water-
insoluble soap, and heating the mixture in the presence of
an alkali.
Cech, C.J., and Bata, A.G. Reclaiming of synthetic rubber
composed of polymers of butadine or its alkyl or halogen
derivatives. German Pat. 743,605 (1943). Kunststoffe
34:24; S.C.L.,22:209).
Comments on the article on "Solution Reclaim". R.A.
(N.Y.) 53: pp. 339, 368 (1943). (S.C.L., 21:268).
Dasher, P.J., Reclaiming vulcanized copolymers of but -
daiene and acrylonitrile U.S. Pat. 2,465,205 (Mar. 22,
1949). (To Goodrich). (C.A., 43:4510; S.C.L., 27:422).
Acrylic ester.
Eby, L.T. Reclaiming synthetic olefin-polyolefin-rubbery
polymers U.S. Pat. 2,471,866 (May 31, 1949). (To Stan -
dard Oil). (C.A., 45:9259; S.C.L., 27:669).
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Flood, D.W., and Mulligan R.A. Method of and apparatus
for reclaiming latex foam. U.S. Pat. 2,719,830 (Oct. 4,
1955). (To U.S. Rubber). (C.A., 50:3793; R.A., 34:828).
Alkali or borate.
Fuchs, H. Solution reclaim. R.A. (N.Y.) 52: pp. 397-98
(1943) (C.A., 37:1897).
General Electric Co., Reclaimed silicone rubber. Brit. Pat.
760,004 (Oct. 31,1956). (R.A., 35:84).
Ghez, H.C. Reclaim compounds with no crude rubber;
Nervastral processes. I.R.W., 106: pp. 14245 (May 1942).
(C.A., 36:6047).
Goyert, M. Swelling behavior of synthetic rubber reclaim in
organic substances, (abstract only) Kaut. u. Gummi, 12:
No. 6, p. WT168 (1959) (R.A., 37:450). Perbunan reclaim.
Green, J. and Sverdrup, E.F. Carboxylic rubbers from scrap
vulcanized rubber. Rev. Gen. Caout., 34: pp. 25-32 (1957).
(R.A., 35:215).
Koepp & Co). (R.A., 36:232). Alternatively the scrap may
be dissolved in hot polyisocyanate and the polyester added.
Griffin, W.R. USP 329,1761 Reclaiming Viton
via acetone, acetic acid and permanganate.
Reclaims
Gummiwerke Odgewald GmbH. Reclaim. Ger. Pat.
1,170,621 (May 21, 1964); Ger. Pat. Abstr., 4 (25): 2
(1964). (R.A.,42:536).
Guzzetta, G. Castellanza, F.S. and Gechele, G.B. Depoly -
merization of styrene in the presence of free radical
generating substances. U.S. Pat. 3,143,536 (Aug. 6, 1964).
(To Montecatini).
Hill, N.C. Reclaiming rubber U.S. Pat. 2,806,821 (Sept. 17,
1957). (To C.P. Hall Co.). (C.A., 52:1966); (R.A., 36:160).
Natural rubber and GR-S.
Hoover, C.F. Butyl reclaim. Rubber Age, 76: p. 725
(1955). (C.A., 49:9315; R.A., 33:209).
Hurley, R.T. Method for reclaiming scrap polyurethane
resins U.S. Pat. 3,143,515 (Aug. 4, 1964). (To Reeves
Bros., Inc.).
Ikuta, S., Tsuzuki, Y., and Takaoka, Y. Mixing GR-I and
GR-S reclaim with natural rubber. J. Soc. Rubber Ind.,
Japan, 22: pp. 100-06 (1949). (C.A., 46:379-; R.A.,
30:289).
Khodkevich, L. Production of colored reclaim by means of
chemical accelerators of reclaiming. Leka. Prom., 8: No. 5,
pp. 26-27 (1959). (R.A., 38:383). The cost about the same
as black reclaim.
Kirby, W.G., and Elliott, P.M. Process of reclaiming waste
polychloroprenes. U.S. Pat. 2,343,558 (March 7, 1944) and
Can. Pat. 431,501 (Nov. 27, 1945). (To U.S. Rubber).
(C.A., 41:4952;S.C.L., 25:207).
Konig, W. Foamed materials from scrap-expanded polyure -
thanes. German Pat. 962,649 (April 25, 1957). (To R.
LeBeau, D.S. Powdered reclaim. Rubber Age, 73:
785-91(1953). (C.A., 48:1045; R.A., 31:163,507).
pp.
Lipetz, S. and Lipetz, A. Reclaiming nylon scrap. Brit. Pat.
936,828 (Sept. 11, 1963). (R.A., 42:55).
McCowan, W.A. Reclaiming polymeric siloxane scrap. Brit.
Pat. 716,024 (Sept. 29, 1954). (To Dunlop). (R.A., 33:31).
Rubber scrap is heated in oxygen-free atmosphere.
Metallgesellishaft, A.-G., Rhenania Ossag., and Mineral -
olwereke, A.-G. Mixtures of rubber, rubberlike substances,
synthetic rubber and synthetic resins. French Pat. 889,110
(S.C.L., 23:235; Rev. Gen. Caout., 21:42).
Metalurgical International, Inc. Chem. Engr. News, 45, no.
38, Sept. 67, p. 36, Impact Process Reclaims PTFE scrap.
Coldstream process for teflon and halon.
Midland Silicones, Ltd. Reclaiming siloxame elastomers.
Brit. Pat. 752,860 (July 18, 1956). (R.A., 34:502).
Anhydrous hydrogen chloride.
Mishustin, I.U. Production of reclaimed rubber containing
fibers. Kauchuk i Rezina, No. 7, pp. 24-28 (1940). (C.A.,
34:8335). From all synthetic rubber containing 20-25%
vegetable fibers.
Moore, D.V., and Thompson, H.H. Reclaiming method.
Can. Pat. 429,743 (Aug. 28,1945) and U.S. Pat. 2,386,707
(Oct. 9, 1945). (To Wingfoot Corp.) (C.A., 39:5121;
40:763). Reclaiming a cured butadiene copolymer with
styrene or acrylonitrile by heating with a swelling agent
which contains ethyl alcohol as a plasticizer.
Nezval, F. Production of reclaim from natural or synthetic
rubber Czechoslovakian Pat. 83,763 (Jan. 3, 1955). (R.A.,
35:586). Leather scrap is subjected to the process of
reclaim along with the comminuted rubber.
Osipovskii, B.Y. and Mamontov, B.V. Reclaiming sodium-
butadiene rubber. Kauchuk i Rezina, No. 4, pp. 61-67
(1940). (C.A., 34:7658).
Pacevitz, H.A. Recovery process for chlorinated rubber.
U.S. Pat. 2,396,000 (Mar. 12, 1946). (To Wingfoot Corp.).
(C.A., 40:3640; S.C.L., 24:281).
Pellison, J. Reclaiming crepe sole scrap.
983,030 (June 18, 1951). (R.A., 30:54).
French Pat.
Phoenix Gummi-Werke. A.—G. Regenerated rubber. Ger.
Pat. 1,132,328 (June 28, 1962): Ger. Pat. Abstr. 2 (30), 2
(1962). (R.A., 40,492). Heating ground vulcanized scrap
rubber which contains nitrogen-containing rubber aux -
ilaries, e.g. antioxidants such phenyl-B-naphthylamine with
methylol compounds of phenol produces compounds which
are insoluble and no longer diffusible in rubber; the reclaim
is colorless or only slightly colored.
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Polyplast Gesellschaft Fur Kautschukchemi m.b.H. Regen -
eration of scrap rubber. Brit. Pat. 761,478 (Nov. 14, 1956).
(R.A., 35:114). Balata and gutta-percha is reclaimed by
mixing with an oxidized extract of a mineral lubricating oil.
Proell, W.A. Thiosulfenyl chlorides and bromides and
polymers made therefrom U.S. Pat. 2,684,952 (July 27,
1954). (To Standard Oil Co.). (R.A., 33:73). Polysulfide
rubbers reclaimed by reacting with chlorine.
Quinn, N.G. Vulcanizing of ebonite; controlled curing of
natural and synthetic rubber ebonites of large cross-section.
I.R.J., 105: pp. 62-63 (July 17, 1943). (C.A., 37:6494).
Repr. in Rubber Chem. Tech. 17: pp. 192-93 (1944).
R.D.L. Bib Reclaiming Foam Mails Vol. Mar. Yr. 60 Ln. 2
Rub. Div. Lib.
Regeneration of S.K. Kauchuk i Rezina, No. 11: pp. 63-73
(1939). (I.R.W., 109,479).
Riolfo, R. "Reversion" method for reclaiming silicone
elastomer scraps Rev. Gen. Caout., 34: pp. 352-54(1957).
(R.A., 35:444).
Rothermel, E.M. Natural and reclaimed rubbers. Rubber
World 135: pp. 892-94 (1957). (R.A., 35:260). Method of
preparing smoked sheet and pale crepe and nine reasons for
using reclaim.
Rubber Reclaiming Co. B.P. 1009592 Recovery of nylon
from tyre scrap. Using 60-75% aqueous formic acid.
Santholzer, R.Reclaiming silicone rubber. Plastics Design
Process 3 (5): 11 (1963). (R.A., 41:486). Four methods are
given.
Sarada, M. Regenerated rubber. Japanese Pat. 177,783
(Feb. 15, 1949). (C.A., 45:9910; R.A., 30:110). Mixed
with waste liquor from sulfite pulp.
Semperit Gummiwerk G.P. 1218715. Reclaimed Rubber,
Pretreat rubber with aldehydes in presence of dil. H2SO.
This type can be used in contact with white or light-colored
PVC without discoloration.
Shokhin, I. Rubber Reclaim Stocks Vol. 18 No. 3 Page 34
Yr 59 Ln 6 Sov. Rub. T.
Slobodin, Y.M. and Matusevich, N.I. Polymerization and
depolymerization. I Depolymerization of rubberlike poly -
mers of isobutylene. J. Gen. Chem. (U.S.S.R.) 16: pp.
2077-82 (1947). (C.A., 41:7803, S.C.L., 26:108).
Societe des Usines Chimiques Rhone-Poulenc. Process for
the reclaim of organopolysioxane elastomers. French Pat.
1,169,639 (Dec. 31, 1958). (Rev. Gen. Caout., 36:370;
R.A., 37:344) by heating in suitable atmosphere at a
temperature between 150 to 350°C.
Stover, A.M. Method of preparing aqueous dispersion of
reclaimed rubber. U.S. Pat. 2,377,052 (May 29, 1945). (To
Goodrich). (C.A., 39:3968; S.C.L., 23:306). Admixing with
the reclaimed rubber not more than 30 parts of carbon
black per 100 parts of reclaimed rubber and thereafter
adding a saponaceous dispersing agent.
Svensson, 0. Dissolving vulcanized rubber waste. Swedish
Pat. 104,698 (1946). (C.A., 40:7692; S.C.L. 25:367).
Sverdrup, E.F., and Elgin J.C. Reclaiming rubber. U.S. Pat.
2,415,449 (Feb. 11, 1947). (To U.S. Rubber Reclaiming
Co.). (C.A., 41:3660; S.C.L., 25:291). Vulcanized conju -
gated diolefin polymer compositions reclaimed.
Sverdrup, E.F. Reclaiming of rubber and production of
hard rubber products. U.S. Pat. 2,809,944 (Oct. 15,1957).
(To U.S. Rubber Reclaiming Co.). (C.A., 52:3392; R.A.,
36:209). Free sulfur and continuously kneading.
Sverdrup, E.F. Reclaimed rubber in discrete particle form.
U.S. Pat. 2,800,462 (July 23, 1957). (To U.S. Rubber
Reclaiming Co). (C.A., 51: 15988; R.A., 36:110). A
method of reclaiming neoprene and butyl rubber.
Sverdrup, E.F. Reclaiming vulcanized rubber in the pres -
ence of unvulcanized high styrene polymeric material U.S.
Pat. 2,845,395 (July 29, 1958). (To U.S. Rubber Re -
claiming Co.). (C.A., 52:19230; R.A., 37:66). Natural
GR-S, nitrile and butyl rubber can be reclaimed.
Ten Broeck, T.R. and Peabody, D.W. Method for reclaiming
cured cellular polyurethane, U.S. Pat. 2,937,151 (May 17,
1960). (To Goodyear). (R.A., 38:637; C.A., 54:19005).
Can be used for foams.
Thompson, H.H. Depigmentizing reclaimed rubber. U.S.
Pat. 2,365,662 (Dec. 26, 1944). (To Wingfoot Corp.).
(C.A., 39:3968; S.C.L., 23:150). Mixing bentonite with the
stock and then extracting with a rubber solvent while the
bentonite inhibits removal of the carbon black by the
solvent.
Thompson, H.H. Rubber reclaim. U.S. Pat. 2,407,193
(Sept. 3, 1946): (To Wingfoot Corp.). (C.A., 41310; S.C.L.,
24:561). Process for preparing non-staining reclaimed rub -
ber.
Torrence, M.F., and Schwertz, H.G. Compounding reclaim
with new elastomers for high quality at low cost. Rubber
Age, 71: pp. 357-60 (1952). (C.A., 46:10672; R.A.,
30:366).
Treves, A. Rubber waste processing. Can. Pat. 426,411
(March 27, 1945). A product, reduced by the process of
Can. Pat. 426,401, which is soluble in crude rubber
solvents.
Tsvetaeva E.M. Kauch i Rezina, 26, no. 6, June 1967, p. 37.
Reclaiming of SKD vulcanzates (Stereoregular butadiene
rubber) reclaimed with fatty acid, plasticizer, and shale-oil.
United States Rubber Co. Polyamide polymer. Belgian Pat.
636,422 (Feb. 28,1964).
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United States Rubber Co. Reclaiming scrap containing
vulcanized copolymers of 1,3 butadiene and monovinyl
compounds: reclaiming waste polychloroprenes Brt. Pat.
575,545 (1946). (C.A., 41:6766; S.C.L, 24:252,253,257).
Vanbreen, A.W. Thermoplastic rubbers Vol. 20 No. 9 Page
373 Sept. 1967 len. 9 Lang. Out. Plastica.
Verein, Glazstoff-Fabrik, A.-G. depolymerization of poly -
ethylene terephthalate. Ger. Pat. 1,143,193 (Feb. 7,1963).
(C.A., 59:7435).
Wallace, E.H. Some notes of reclaim rubber compounds.
I.R.J., 103; pp. 633-35 638 (1942) (S.C.L., 20:411).
Warren, S.F., and U.S. Rubber Reclaiming Co., Inc.
Reclaiming natural and synthetic rubber. British Pat.
610,901 (S.C.L., 27: 158). Organic disulfide.
Wendrow, B.R., and Spalding, D.P. Silicone rubber reclaim.
Rubber World 138: pp. 73842 (1958). (C.A., 52:21205;
R.A., 35:502; 36:502). Silicone rubber can be reclaimed.
Wingfoot Corp. Regenerating copolymers. British Pat.
615,865. (C.A., 45:1378; S.C.L., 27:324). Mix rubber with
coal tar distillate and heat.
Winkelmann, H.A. Reclaiming neoprene.
2,313,693 (Mar. 9,1943). (C.A, 37:5284).
U.S. Pat.
Zakharov, N.D., Bogdanovich, N.A. and Volkova, M.I.
Reclaim of butadiene-nitrile rubber. Izy, Vyssh. Uchebn.
Zaved. Khim. i Khlm Tekhn., 3: No. 3, pp; 527-33 (1960).
(R.A., 38:637; C.A., 54:23397) Used in brake lining.
Waste From Rubber Industry
Heap, Morrell, Journal App. Chem. vol. 18, no. 7 p. 189
Microbiological Deterioration of Rubber and Plastics. Fil -
lers more susceptible to microbe destruction.
Heinisch, K.F. and Nadarajah, M. Disposal of factory
effluents from crepe and sheet producing factories. I.II.
Rubber Res. Inst. Ceylon Quart. J., 39 (1-2): 32:37 (1963).
(R.A., 41:551). The main effluent is rubber serum (acid in
reaction) diluted with water, which can be rendered
innocuous by passage through a series of tanks, one of
which contains limestone.
Lewis, S.C. Reclaimed rubber. Waste Trades Manual and
Directory pp. 61,63,65 (1948). (S.C.L., 27:348).
Rostenback, R.E. Synthetic rubber wastes. Sewage & Ind.
Wastes, 24: pp. 113843 (1952). (C.A., 46:11752; R.A.,
31:455).
Rostler, F., and Mehner-Wilson, V. Reclaim from vul -
canized rubber scrap. German Pat. 909,041 (March 4,
1954). (To Metallgesellschaft Aktienges. Naftolen Ges.
m.b.H.). (R.A., 33:59). Refinery wastes.
Rubber Raw Materials, Ltd. Diversity of rubber scrap.
Rubber Age & Synthetics, 33: p. 137. (1952). (R.A.,
30:310).
Ruchhoft, C.C., Placak, O.R., and DeMartini, F.E. Investi -
gations disclose successful disposal methods for synthetic
rubber waste. Civil Eng., 17: No. 2, pp. 59-60 (1947).'
(C.A., 41:7806, 7807; S.C.L., 26:104). Coagulation, oza -
onation, addition of activated carbon, breakpoint chlorina -
tion and aeration.
United Kingdom Ministry of Supply. Utilization of syn -
thetic and natural rubber waste. Advisory Service on
Rubber, Circular No. G-4 (May, 1946). (S.C.L., 24:350).
Wilson, A.W.G. Junk and industrial wastes. Can. Chem.
Process Ind., 25: pp. 163-67 (Apr. 1941). Importance of
scrap.
Zigmund, V.A., and Petroy,
Kauchuk i Rezina No. 7:
24:444,1.R.W., 114:374).
M.V. Crude rubber waste.
pp. 50-51 (1940). (S.C.L.,
Waflet, F.E. Reclaimed rubber. A little publicized domestic
source of supply. Chemical industries, 47: No. 1, pp. 27-29
(July 1940). Review of American facilities.
Yasunkskaya, F. Problems in the economics of using
reclaim Kauchuk i Rezina, 18: No. 1, p. 54 (1959). (R.A.,
37:428), A plea is made for a more extensive use of
reclaim.
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