United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S2-82-103  Mar. 1983
Project Summary
Status, Trends and
Implications  of Carbon
Fiber  Material  Use
Benjamin L Blaney
  This study estimates the future usage
of carbon fiber composite materials in
both consumer and industrial products,
and the resultant economic impact of
the disposal of these products and indus-
trial  scrap in both the municipal and
industrial waste streams. The technical
and economic substitutability of carbon
fiber composite materials for materials
now in use is analyzed, and the major
uses of this material forecasted. Poten-
tial problems relating to the disposal of
products containing carbon fiber mate-
rials are analyzed, and estimates  are
made of the economic impacts of the
disposal of these products for alterna-
tive scenarios that cover a wide range of
disposal technologies.  The economic
impact of the disposal of products and
industrial scrap containing carbon fiber
composite materials is found to be
small for all of the scenarios investi-
gated.

  This Project Summary was developed
by EPA's Industrial Environmental Re-
search Laboratory, Cincinnati^ OH, to
announce key findings of the research
project that is  fully documented in a
separate report of the same title (see
Project Report ordering information at
back).

Introduction
  Carbon fiber is produced by subjecting
polyacrylonitrile or petroleum pitch fibers
to high temperature and pressure. The
resultant fibers  have a graphitic molec-
ular structure which makes them high in
tensile strength, light in weight, and
resistant to corrosion. Fibers are also
good electrical conductors and do not
readily oxidize except at high temper-
atures. Carbon fiber composite materials
are made  by binding the fibers in a
thermosetting or thermoplastic resin ma-
trix. Currently, composites are predomi-
nately used in the transportation sector
(e.g. for aircraft parts). They are also used
for the construction of prostheses and
other consumer goods such as golf clubs
and tennis racquets. Because of some of
the carbon fibers, properties of their
release into the atmosphere could result
in unfavorable environmental impacts.
The objective of this study was to deter-
mine whether the disposal of consumer
goods or industrial products  containing
carbon fiber reinforced plastics ("carbon
fiber composite materials") would result
in environmental  impacts of economic
consequence.
  This study investigated the economic
and technical incentives for the  use of
carbon fiber materials, projecting demand
to 1990. It identified the life cycle of
different categories of carbon fiber prod-
ucts and determined the disposal paths
for each. Since the useful lives of these
products range from five to 10 years  for
sports equipment to 20 or more years  for
aerospace items, most of the carbon fiber
produced in 1990 will not enter the waste
stream until  the  early  2000s.  It can
therefore be assumed that the carbon
fiber disposal rate will be equal to or less
than the 1990 production rate for 10 to 15
years after 1990. This period is referred to
in the report as "post-1990." The study
projected the annual economic impact of
carbon fibers released from waste dis-
posal during this time.

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  For the purpose of this study, carbon
fiber  refuse was aggregated into two
groups: that  which entered  municipal
waste streams and that which was dis-
posed of in  industrial waste streams.
Points of release to the environment were
identified and estimates were made  of
annual fiber release rates for each of the
waste streams. With the use of previously
published risk assessments which deter-
mined the impacts of carbon fibers in the
environment as a function of fiber
release, estimates were made of the cost
(in dollars) arising during the disposal of
carbon fiber composites.
  Because  carbon fibers are good elec-
trical conductors and are very light weight,
they may be dispersed over a  large area
and  could damage electrical equipment.
The  study  therefore  focused the cost
analysis on electrical failures arising from
carbon fibers released during disposal.
  Only the impacts of incinerating carbon
fiber composite material were addressed.
Those associated with incinerating raw
carbon  fiber  or preimpregnated  carbon
fiber materials were  not  analyzed, be-
cause manufacturers were found to  be
aware of potential  hazards associated
with incinerating these materials and to
use  other  disposal techniques. Also,
because of the high cost of carbon fiber,
steps have been taken to minimize the
amount of scrap from these materials.
  Health hazards from carbon fiber re-
lease were not considered in this study
because the  extant health effects data
when the  study  was performed were
insufficient for the derivation  of risk
functions.
  The results of this report are based on
calculations which use  a  number of
engineering  estimates. Besides  projec-
tions of future demand for carbon fiber
composite materials, estimates were
made of scrap disposal pathways, incin-
erator release rates, pollution  control
equipment efficiencies,  and electrical
damage functions.  Conservatively high
estimates of  carbon fiber  use, and fiber
release rates were used to indicate  an
upper limit  to potential  impacts. Ten
disposal scenarios  were  considered to
account for varying percentages of com-
posite scrap recycled, landfilled, or incin-
erated.

 Findings and Conclusions

 Future Composite Use
   There are  many current and potential
 applications for carbon fiber composites
 in both consumer and industrial  sectors.
 The extent to which  composites  will be
substituted for conventional  structural
materials will be determined by their cost
effectiveness, which varies from applica-
tion to application.  Composites  will be
used in consumer goods when the buyer
is willing to pay the extra cost (often twice
the current price of alternative materials)
for durability  and  light weight. In the
transportation  sector, composites will be
used because they are corrosion resistant
and because their high strength-to-weight
and stiffness-to-weight ratios can result
In fuel savings.
  Table 1  shows projected  carbon fiber
demand for various  industrial  sectors to
1990. It can be  seen that  in  the near-
term, the aerospace industry will be the
principal user  of composites, while  to-
wards the end of the 1980s, demand in
the automobile industry is  expected to
increase substantially. Demand for fibers
in sporting goods and for miscellaneous
applications is not expected to grow as
rapidly.
  Three principal benefits  result from
using carbon fiber  in the transportation
sector. First, production costs are reduced
because of design simplification. Second-
ly, carbon fiber composites have a longer
life   in  many applications  and
therefore reduce  maintenance costs.
Thirdly  and most  importantly,  carbon
fiber use saves fuel. If graphite springs
are  used  for  double-axle  trucks, it  is
estimated that body  weight  would be
reduced by 272 pounds, resulting m pre-
tax profits in the range of $100 to $800
pertruck. If graphite sidewalls, partitions,
celling and stowage bins are used in a
fleet of 1,383 three-engine Boeing 767s,
it is estimated that $60 million would be
saved from  reduced  fuel  consumption
during the lifetime of the fleet. (Note that
the carbon fiber used in this fleet is 2
percent of the total  estimated industrial
fiber use in 1990; the use of carbon fiber
in other transportation vehicles should
further increase fuel savings.)
 Table 1.
                                     Disposal of Composite
                                     Materials
                                       Carbon  fiber entering the  municipa
                                     waste stream is expected to be composec
                                     primarily of discarded consumer products
                                     (In  this study, automobile disposal is
                                     considered under industrial waste streams.
                                     Most sports  equipment manufacturer;
                                     produce little composite scrap (in the 1 tc
                                     5 percent  range), because composit*
                                     costs are high and manufacturers attemp
                                     to minimize waste by designing efficiently
                                     and by turning  scrap  into marketabk
                                     items.  The same appears to be  true fo
                                     manufacturers of other consumer goods
                                     Therefore, the contribution from consum
                                     er goods  manufacturers to municipa
                                     waste  is essentially negligible. Approxi
                                     mately 5OO kg of carbon fiber composit*
                                     enter the municipal waste stream annu
                                     ally from the disposal of consumer goods
                                       Industrial scrappage,  used  industria
                                     products, and oversized consumer prod
                                     ucts enter the industrial waste  stream
                                     The quantity of fiber consumed (and thus
                                     disposed of) throughout the  industria
                                     sector  is much larger than  that  used ir
                                     consumer  goods.  Nine  percent of  th«
                                     carbon fiber produced in 1980 was fabri
                                     cation scrap and thus entered the indus
                                     trial waste stream immediately, while 6^
                                     percent was used in industrial products
                                     The remainder went to consumer goods
                                     Thus about 73 percent of the fiber pro
                                     duced will eventually enter the industria
                                     solid waste stream. It is estimated tha
                                     approximately 82 percent of the carbor
                                     fiber produced  in  1990 (about 720(
                                     tonnes) will eventually enter the indus
                                     trial refuse stream.


                                     Waste Disposal Paths
                                       The method of disposal  of municipa
                                     and  industrial waste is an importam
                                     determinant of the likelihood  that fibei
                                     will be released and thus that the envi-
                                     ronment will be affected. As of 1980 the
        U.S. Carbon Fiber Demand Projections Through 1390, 1000 Kilograms
        11000 Pounds)*
Demand                                     Year
 Sector                1980           1983            1985          1990
Aerospace
Sporting Goods
Automobile
Other Industries
Totals
182 (400)
141 (310)
6(141
87(192)
416(916)
591 (1300)
227 (500)
45(100)
159 (350)
1022(2250)
WOO (2200)
318(700)
91 (200)
227 (500)
1636(3600)
2273 (5000)
591 (1300)
4545 (10000.
409 (900)
7818(17200,
 'Source: Composite Market Reports. Inc., "Annual Market Estimate for Graphite, Prepreg am
        Fiber, 1979 through 1985," (1980), and personal communications.

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disposition of municipal  waste was as
follows:
  • 89 percent landfill
  • 4 percent incinerated without recov-
    ery
  • 1 percentincmeratedforenergyrecov-
    ery
  • 6 percent source separation
  Many pressures, including increases in
energy costs, shortages in land available
for landfill, and environmental concerns
favor changing this mix in the future.
These pressures  were  accounted for
when environmental impacts were pro-
jected in terms of  several different sce-
narios for future municipal waste dispos-
al.
  The manufacturers of  fiber tend to
recycle,  reuse or otherwise  limit  the
amount of scrap produced. Many recycle
the carbon fiber scrap by chopping it up.
When disposal is necessary, some type of
container is used to segregate the fiber
from other industrial wastes. Subsequent-
ly, the containers  are usually  placed in
landfills, although  they are occasionally
stored. It was  estimated that only  0.5
percent  of the carbon  fiber used  by
industry now enters the industrial  waste
stream. Future incineration trends  are
reflected in five industrial waste disposal
scenarios in the full report.
  Most carbon manufacturers and pre-
impregnators are conscientious in  advis-
ing their customers about handling car-
bon fiber material. Some attach  labels
stating acceptable disposal procedures,
whereas others recommend recycling.
  In general, the aerospace industry
takes appropriate precautions when dis-
posi ng of carbon fiber scrap. The firms are
knowledgeable about the properties of
carbon fiber and composites. Many aero-
space firms generate a substantial amount
of scrap but have not instituted recycling
programs. Most scrap is segregated and
landfilled. Some companies cure their
scrap into blocks, whereas others put the
scrap into 55 gallon drums.
  The amount of scrap produced by the
remaining users of carbon fiber is small.
Many of these companies are in  the
research and development stage and use
very little carbon fiber. Companies already
producing carbon fiber generally landfill
the scrap.
  Industrially used products containing
carbon fiber range  from loom shuttles to
both structural and non-structural parts
of commercial aircraft. Disposal of these
products varies, depending on the appli-
cation. Because of the  tight  manifest
control system maintained for all military
and commercial airplane parts  in this
country,  disposal  is generally through
landfilling, not incineration. Automobiles
are scrapped  and  non-recyclable parts
such as those made of carbon fiber are
landfilled. In the future, approximately 10
percent  of  the  carbon  fiber used in
automobiles  may  reach  the municipal
waste  stream after being discarded by
repair  shops, specialty body shops, and
the like.  Carbon fiber products used in
non-transportation industries will be dis-
carded with other industrial waste.

Release Mechanisms and
Cost  Impacts
  Carbon fibers are released during dis-
posal principally from incinerators.  Be-
cause  carbon fibers are oxidized only at
high temperatures (above 1000°C), the
composite matnx(e.g.,athermosetresin)
is rapidly destroyed  during combustion
and fibers may be  entrained in combus-
tion gases and emitted from the stack of
the incinerator
  Two other potential fiber release mech-
anisms were shown to be insignificant.
One was from fires in landfills and the
other  was due to explosions  in waste
shredding operations. A third release
mechanism,  paniculate emissions from
waste shredding  operations,  is being
investigated further by the U.S. EPA.
  Estimated fiber release  rates from
municipal mass-fired incinerators  with
various pollution control and waste heat
recovery equipment are shown in Table 2.
The fiber release rate from incinerators is
affected by the type of incinerator, pollu-
tion control  equipment, and waste heat
recovery equipment employed. The re-
lease rates were calculated assuming a
conservatively high upper bound to the
uncontrolled fiber  release of 4 percent
(i.e. 4 kg of fibers released per  100 kg of
composite incinerated).
  The estimated annual average econom-
ic impact arising  from the  disposal of
Ttble 2-    Fiber Release Rates for Municipal
           Incinerators with Various Forms
           of Paniculate Control
                         Stack Release
    Particle Control         of Free Fibers
       System                 (%)

No Active System (Cyclone)       3.6
Bag House                    0.04
Wet Scrubber                  1.2
Electrostatic Precipitator         0.8
  (ESP)
Heat Recovery and ESP          0.24
carbon fiber in municipal waste streams
is very small, as shown fn Table 3. The
upper bound case—Scenario 5—assumes
that all municipal waste would be incin-
erated,  requiring  over 900  new, large
incinerators. This incineration  rate is
unlikely in the 1990s.
  Industrial incineration will take place
predominately in multi-chamberandstarved-
air units, with lesser use of fluidized bed,
multi-hearth, rotary kiln and single cham-
ber incinerators. Release rates for both
multi-chamber and starved-air units were
estimated to be 0.12  percent and 0.36
percent, with and without waste  heat
recovery units.
  A much larger volume  of composite
material may enter the waste stream at a
manufacturing plant or may be discarded
as part of the transportation equipment
waste stream. Table 4 shows the econom-
ic impacts obtained from  the  five sce-
narios for type and volume of industrial
waste disposal. The most  likely upper
bound to fiber release is represented by
Scenario D,  in which  10 percent of the
composite  material in  automobiles is
incinerated along with all industrial waste
from non-aerospace industries. This sce-
nario  also reflects the  incinerator mix
likely to be used by industry in the 1990s
and shows a very small economic impact
from carbon fiber disposal.
Table 3.   Comparison of Scenarios Considered for Composite Disposal in Municipal Sector




1.
2.
3.
4.

5.



Scenario
Baseline Case
Near Future Case
Far Future Case
Intensive Energy
Recovery Case
Upper Bound Case
Total
Number
of
Incinerators
41
51
39

487
989
Percent
of
Refuse
Burned
4
5
a

60
100
Carbon
Fiber
Burned
(Kg/Day)
80
100
160

1.200
2.000


Annual
Cost
$ 1.693
$ 1.828
$ 1.197

$ 6.795
$27.306

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   To determine an extreme upper bound
 to economic impacts of carbon  fiber
 disposal in the industrial waste stream, it
 was assumed in Scenario E that  all
 carbon fiber used in industry was incin-
 erated and  that incineration occurred
 using the  least efficient incinerators
 considered in this study (i.e. municipal
 incinerators with no active controls). The
 resultant annual cost of  approximately
 two million dollars is still low compared to
 benefits of carbon fiber (e.g. fuel savings).
 In any case, it is highly unlikely that all
 carbon fiber composite used in industry
 will be disposed of through  incineration
 or that incinerators with such high emis-
 sion rates will be used.
      Table 4. '  Comparison of Scenarios in Industrial Sector

A
B



C




D




E

Scenarios
Baseline Case
Future Trend
Case


Current Upper
Bound



Future Upper
Bound



Worst Possible
Case
Disposal
Practices
Current'
Current



Aerospace Scrap
Landfilled
J 0% A utomobile + 1 00%
All Other Industrial
Waste Incinerated
Aerospace Scrap
Landfilled
1 0% A utomobile + ; 00%
A II Other Industrial
Waste Incinerated
All Industrial
Waste Incinerated
Incinerator
Population
Current
No Single Chamber



Current




No Single Chamber




Least Efficient
Type (Municipal)
Paniculate
Control
None
With Heat
Recovery
(+Wet
Scrubbers)
None




With Heat
Recovery
t+Wet
Scrubbers)

None

Cost Pei
Year ($)
5,250
466



131.351




11.660




1,907.999

                                         BAs of 1980.
    This Project Summary was prepared by staff of Econ, Inc., Princeton, NJ 08540;
     the EPA author Benjamin L. Blaney (also the EPA Project Officer, see below) is
     with the Industrial Environmental Research Laboratory. Cincinnati, OH 45268.
    The complete report, entitled "Status,  Trends and Implications of Carbon Fiber
     Material Use," (Order No. PB 83-147 751; Cost: $ 16.00, subject to change) will
     be available only from:
           National Technical Information Service
           5285 Port Royal Road
           Springfield, VA 22161
           Telephone: 703-487-4650
    The EPA Project Officer can be contacted at:
           Industrial Environmental Research Laboratory
           U.S. Environmental Protection Agency
           Cincinnati, OH 45268
                      UU.S. Government Printing Office.  1983-659-017/7025
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
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Fees Paid
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EPA 335
Official Business
Penalty for Private Use $300

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