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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