Using carbon fiber as the material for car body panels could reduce energy consumption and CO2 emissions. Analysis shows the current materials, steel and aluminum alloys, account for 67.87% of material energy use and 75.38% of CO2 emissions. Replacing them with carbon fiber for the car body, which makes up 20% of vehicle weight, could reduce total energy use by 9.6% and CO2 emissions by 9.7% according to calculations. However, carbon fiber is more expensive to produce initially and is not currently recyclable. A new design would also be required to implement this material change.

1. 0
The Effectiveness of Using Carbon Fiber as the Material for Cars’ Body
Panel
Ahmad Alkhathami
University of St. Thomas
May 4, 2011
Sustainability Proposal
Materials Engineering
ETLS 771
Spring 2011

2. 1
Abstract
The objective of this paper is to search for a substitute material for the existent car body
material. Therefore, the reduction of energy consumption and CO2 footprint will occur. The
paper addresses analysis of the current material energy consumption and CO2 footprint by using
CES EduPack. Then, a proposal was developed of using carbon fiber as the new material of the
car body. The analysis of the Energy consumption and CO2 footprint shows that there is a great
saving with the new material. However, the higher cost of the carbon fiber could continue to be a
barrier for the industry.
There is a rapid growth in the demand on transportation vehicles caused by the high growth in
population and the increase in living standards in the world in general and many of the
developing countries in particular. This increase in the transportation demand has caused
increase in energy demand. As a result, more energy is consumed and more emission of carbon
dioxide has released to the environment. Governments today put pressure more than any time
before on the automobile manufacturers to produce cars that are more efficient in term of energy
saving and reduction of carbon dioxide emission.
The purpose of this proposal is to look for new materials to be used in the family car to reduce
the energy consumption and the carbon dioxide footprint. The focus will be on the two areas of
high energy and carbon footprint rate which are the material and use phases of the product life
cycle which is show in the diagrams below from the CES EduPack.
Hopefully, this proposal will come up with new material to be used that will reduce the
energy consumption and CO2 footprint. In addition, it will reduce the cost while increasing the
life time of the product.
For long time, the materials used in making cars have been a source of concern for cars’
manufacturers. The percentage of the Aluminum materials used in the car has growing as a
substitute of Steel. However, despite its light weight and the saving of energy and CO2 in
transportation, aluminum still has limited applications due to the high price and the high energy
of making the material.

3. 2
Current case
The report below shows a summary about the energy and the CO2 footprint of the family car1
Energy Analysis
Phase Energy (J) Energy (%) CO2 (kg) CO2 (%)
Material 1.1734E+011 12.15 6127.1783 9.11
Manufacture 1.1164E+010 1.16 872.1888 1.30
Transport 0.0000 0.00 0.0000 0.00
Use 9.0143E+011 93.32 64001.1750 95.12
End of life -6.3935E+010 -6.62 -3719.3309 -5.53
Total 9.6599E+011 100 67281.2113 100
1 CES EduPack 2010.

4. 3
The diagrams and the table above show that making the material is accountable of
12.15% of the energy, and 9.11% of the CO2. The use phase of the product is accountable of
93.32% of energy consumption and the release of 95.12% of the total CO2. It appears clearly
that most of the energy and CO2 come from the material and use phases. As a result, the focus in
this project will be in finding the material that will best reduce the energy and the CO2 in these
two areas. The analysis will be on the data that are related to these two phases.
The table above breaks down the product into its major materials showing the energy for making
them, and the total mass.
Component Material
Recycle
content
Material
Embodied
Energy *
(J/kg)
Total
Mass
(kg)
Energy (J) %
Steel content
Low alloy
steel
Typical
%
2.434E+007 850.000 2.069E+010 17.63
Aluminium
content
Cast Al-
alloys
Typical
%
1.346E+008 438.000 5.895E+010 50.24
Thermoplastic
content (PU
&PVC)
Polyurethane
(tpPUR)
Virgin
(0%)
1.188E+008 148.000 1.759E+010 14.99
Thermoset
content
Polyester
Virgin
(0%)
8.839E+007 93.000 8.220E+009 7.01
Elastomer
content
Butyl rubber
(IIR)
Virgin
(0%)
1.068E+008 40.000 4.271E+009 3.64
Glass content
Borosilicate
glass
Typical
%
2.217E+007 40.000 8.867E+008 0.76
Other metal
content
Copper
Typical
%
4.812E+007 61.000 2.935E+009 2.50
Textile
content
Polyethylene
(PE)
Virgin
(0%)
8.085E+007 47.000 3.800E+009 3.24
Total 1717.000 1.173E+011 100

5. 4
As we see, Steel and Aluminum alloys are the two major materials that consume about
67.87% of the total material energy. Also, they both hold about 75% of the total mass. Steel by
itself is accountable of about half of the total weight of the product (49.5%).
Energy consumed during the use phase:
Mode Energy (J) %
Static 0.000
Mobile 9.014E+011 100.00
Total 9.014E+011 100
CO2 Footprint analysis
1.57
Total 1717.000 6127.178 100
Textile content Polyethylene (PE) Virgin (0%) 2.052 47.000 96.459
0.78
Other metal content Copper Typical % 3.553 61.000 216.738 3.54
Glass content Borosilicate glass Typical % 1.195 40.000 47.783
4.32
Elastomer content Butyl rubber (IIR) Virgin (0%) 3.888 40.000 155.538 2.54
Thermoset content Polyester Virgin (0%) 2.846 93.000 264.683
54.88
Thermoplastic content (PU &PVC) Polyurethane (tpPUR) Virgin (0%) 4.912 148.000 727.004 11.87
Aluminium content Cast Al-alloys Typical % 7.677 438.000 3362.597
%
Steel content Low alloy steel Typical % 1.478 850.000 1256.377 20.50
Component Material Recycle
content
Material CO2
Footprint *
Total Mass
(kg)
CO2
Footprint
By narrowing our analysis to the two phases (material and use) and to the two materials (Steel
and Aluminum), Steel and Aluminum release most of the CO2, 75.38%, which confirms to us
that those two materials are what should we address to reduce the energy and CO2 impact.
The use phase:
Mode CO2 Footprint (kg) %
Static 0.000
Mobile 64001.175 100.00
Total 64001.175 100

6. 5
Material and product for the analysis
From the analysis above, we see that we have two targets the Steel alloys and Aluminum
alloys. Aluminum alloys is used mostly for pistons and cylinder lines because of its good thermal
conductivity and low expansion. The low alloy steel is used for the car engine and the
transmission components.
However, the area of the analysis will be in the materials used for the car body, for many
reasons such as that car body contributes 20% to the total weight of the car.2 Also, car body does
not need high properties as those used in the engine or the transmission.
The materials that are used in the car body are low alloy steel and Cast-aluminum alloy. Since
it is hard to know the exact percentage of each of them, I assumed that 50% of the car body
materials are made of low alloy steel and 50% is made of Cast-aluminum alloy.
The substitute material for the car body will be the carbon fiber. Further analysis of using
carbon fiber as the material for the car body panel is provided below.
The table below compares some of the important properties of the existing materials with the
Carbon Fiber reinforced composites.3
Property Low alloy steel Cast Al-alloys Fiber carbon Results (good-bad)
Price $/kg 0.8 1.91 44.1
Expensive, yet high
volume per Kg
comparing to Steel &
AL
Yield Strength 1.5 MPa 0.33 MPa 1.05 MPa Good
Tensile strength 1.7 MPa 0.38 MPa 1.05 MPa Good
Hardness 6.79 MPa 1.47 MPa 0.211 MPa Good
stiffness4
High High High
Fatigue strength 0.7 MPa 0.157 MPa 0.3 MPa Good
Embodied energy J/kg 3.8 e7 2.38 e8 2.86 e8
Bad (in primary
production)
CO2 footprint kg/kg 2.3 13.1 18.5
Bad(in primary
production)
Recyclability Yes Yes No Bad
Production process
Casting, forming,
Machining, welding,
soldering
Casting, forming,
Machining, welding,
soldering
Molding-
machining
good
2
CarleD., Blount G. The suitability of Aluminiumas an Alternative Materialfor Car Bodies.
3 CES EduPack 2010.
4
Jambor A., Beyer M. New Cars-New Materials.

7. 6
The table shows that Carbon Fiber reinforced composites is a strong material that can be
substituted in the car body. The material results for the embodied energy and CO2 footprint are
not satisfactory. However, that only for the primary production, as the material is light it is
expected to save more energy during the use phase of the product.
Calculation of the energy and CO2 for using Carbon Fiber in the car body
A study showed that using carbon fiber can reduce the weight of the car up to 50%.5 6
Therefore, this percentage will be used in the calculation for the 20% of the total weight of the
car which is dedicated for the body. Then, a new report from the CES EduPack will be produced
with the amount of the materials needed to get the new results when carbon fiber is the material
used for the car body panel instead of Steel and Alum.
The total body weight= 20% * 1717 kg= 343.4 kg.
The new weight of the body due to using the new material = 50% * 343.4= 171.7 kg
We assume that the 50% reduction in the weigh half of it from the steel and half from the Al.
The new results for using Carbon fiber reinforcement composites in the car body are showing
below:
5 Reinforced Plastics.Faster production of carbon fibrecar parts.
6 Jambor A., Beyer M. New Cars-New Materials.

8. 7
Phase Energy (J)
Energy
(%)
CO2 (kg) CO2 (%)
Material 1.0370E+011 11.88 5341.1998 8.80
Manufacture 1.0653E+010 1.22 835.4550 1.38
Transport 0.0000 0.00 0.0000 0.00
Use 8.1128E+011 92.96 57601.0575 94.91
End of life -
5.2948E+010
-6.07 -3088.3454 -5.09
Total 8.7268E+011 100 60689.3670 100
By comparing the total energy and the CO2 footprint we find the following
The old material The new material
Total energy J 9.6599E+011 8.7268 e11
CO2 Kg 67281.2113 60689.367
The table shows that the carbon fiber has achieved reduction in energy by 9.6%. It also achieved
a reduction in CO2 by 9.7%.

9. 8
Material Analysis:
Component Material
Recycl
e
conte
nt
Material
Embodie
d Energy
* (J/kg)
Total
Mass
(kg)
Energy
(J)
%
Total
Mass
(kg)
Steel
content
Low alloy
steel
Typical
%
2.434E+0
07
764.15
0
1.860E+0
10
17.9
4
764.15
Aluminium
content
Cast Al-
alloys
Typical
%
1.346E+0
08
352.15
0
4.740E+0
10
45.7
1
352.15
Thermoplas
tic content
(PU &PVC)
Polyuretha
ne (tpPUR)
Virgin
(0%)
1.188E+0
08
148.00
0
1.759E+0
10
16.9
6
148.00
0
Thermoset
content
Polyester
Virgin
(0%)
8.839E+0
07
93.000
8.220E+0
09
7.93
93
Elastomer
content
Butyl
rubber
(IIR)
Virgin
(0%)
1.068E+0
08
40.000
4.271E+0
09
4.12
40
Glass
content
Borosilicat
e glass
Typical
%
2.217E+0
07
40.000
8.867E+0
08
0.86
40
Other metal
content
Copper
Typical
%
4.812E+0
07
61.000
2.935E+0
09
2.83
61
Textile
content
Polyethyle
ne (PE)
Virgin
(0%)
8.085E+0
07
47.000
3.800E+0
09
3.66
47
Total
1545.3
00
1.037E+0
11
100
1545.3
The material diagram above shows that the overall energy used for material production reduced
by 11%, while there is a reduction in the product mass by 10%.
Energy consumed during the use phase:
Mode Energy (J) %
Static 0.000
Mobile 8.113E+011 100.00
Total 8.113E+011 100
The reduction of energy during the use phase is about 10%. Furthermore, the new material
reduces the manufacturing energy by 4.56%. However, at the end of life for the product, the
saving in energy is less than the saving using the old materials by 17.2%. This is due to the fact
that carbon fiber is not recyclable, at least till these days.

10. 9
CO2 Footprint analysis
The material phase analysis
Component Material
Recycle
content
Material
CO2
Footprint
* (kg/kg)
Total
Mass
(kg)
CO2
Footprint
(kg)
%
Steel content
Low alloy
steel
Typical
%
1.478 764.150 1129.483 21.15
Aluminium
content
Cast Al-alloys
Typical
%
7.677 352.150 2703.513 50.62
Thermoplastic
content (PU
&PVC)
Polyurethane
(tpPUR)
Virgin
(0%)
4.912 148.000 727.004 13.61
Thermoset
content
Polyester
Virgin
(0%)
2.846 93.000 264.683 4.96
Elastomer
content
Butyl rubber
(IIR)
Virgin
(0%)
3.888 40.000 155.538 2.91
Glass content
Borosilicate
glass
Typical
%
1.195 40.000 47.783 0.89
Other metal
content
Copper
Typical
%
3.553 61.000 216.738 4.06
Textile content
Polyethylene
(PE)
Virgin
(0%)
2.052 47.000 96.459 1.81
Total 1545.300 5341.200 100
The CO2 footprint has been reduced by using the Carbon fiber 12.8% only in the material phase.
In the use phase
Mode CO2 Footprint (kg) %
Static 0.000
Mobile 57601.058 100.00
Total 57601.058 100
The Carbon Fiber material reduces the CO2 footprint by 10%.

11. 10
Constraints:
- The new design should not exceed the current weight of the product.
- The new design should meet the current safety standers.
- It should meet the current specifications of strength, stiffness and crash resistance
Objectives:
- Achieving reduction in material, energy consumption, and CO2 emissions, while
maintaining the production costs.
- Achieving durability.
- Achieving recyclability.
From the above analysis, it appears that there are great benefits from using the carbon fiber in the
car body. Further analysis for the cost is showing below
Costs calculations
1) the body material’s cost:
In the old product the cost of the materials according to our estimation of the total weight and
percentage of low alloy steel and cast Al-alloys, and using the price rate of the materials from
CES EduPack:
Cost of steel: 171.7 kg*0.844= $145
Cost of Al: 171.7 kg*1.91=$328. Therefore, the total cost of the body materials is $473
Using the new Materials (carbon fiber) with total weight of 171.7 after the reduction of 50%:
Total cost of body material= 171.7*44.1= $7572
As a result, using the carbon fiber as a body panel material will end up spending $7099 more
than using the old materials.
2) The energy cost
Using carbon fiber will result in total reduction of energy by 9.6%, 9.331 × 1010
Joule.

12. 11
To calculate the energy saving throughout the product life cycle we assume that all the saved
energy are from the use phase, which is in term of gas saving. Therefore, by converting the
energy from Joule to gallon, the cost of saving in gas for 9.331 × 1010
Joule will be about
708.1815422 gallon US.
The saving in dollars according to the recent oil price of $3.99 per gallon:
708.1815422 × 3.99 = $282536
Therefore, the spending on the new material comparing to the old one will be
7099 − 2825.64 = $ 4273
There are still many other factors that will result in further reduction of the gap between the two
costs. For instance the cost of saving in labor since the molding process of carbon fiber is less
expensive than the cost in case of steel or Al. Also, the cost of saving in the CO2 footprint and
the saving of the manufacturing and transportation of the product will reduce the gap further. The
calculation of those factors may need further research in that scope in particular.
The new materials:
The cost of using the new material is higher than the current one. That may explain the reason
why carbon fiber has not been used in a wide application of mass production in automobile
manufacturing. It has only few applications such as in the race cars. Despite the high costs of the
carbon fiber, there are many advantages that make the carbon fiber the best material for the
future cars. Some of its advantages are
- Carbon fiber consumes less energy and release less CO2, which benefits the environment
and save energy resources.
- It is a corrosion resistance
- Carbon fiber improve performance
- It is Flexible, light, and strong
- It improves fuel efficiency
- Durable which results in a longer and more reliable vehicle lifetime.

13. 12
- It is more easily molded with complex shapes, therefore, Less material and few number
of parts can be used
- It needs lower labor
Carbon Fiber has some disadvantages that work as barriers from using this material
- The most obvious disadvantage is the higher cost of the material comparing to the cost
of steel and Aluminum alloys.
- Also, Carbon Fiber is not a recyclable material, which makes the material ends up in the
land filled at the end of the product life. However, new programs of recycling Carbon
fiber have started. For instance, Trek Bicycle has implemented a recycling program for
its carbon fiber. They now recycle all of its scrap carbon fiber material.7 With the
demand of using the material in wide range of industries such as aerospace, Medical,
and automobile, I expect that recycling of the material will be more applicable with the
increase of the volume.
Conclusion
Despite the challenges, carbon fiber is the focus of the car manufacturers in the last few years.
A lot of researches are taking place. With the increase of the applications and finding more
economical ways of producing the material through the economies of scales, the material could
rapidly access the market through mass production in the following years.
Based on the research of the properties and advantages of carbon fiber, it is a good solution for
the automobile industry. The material provides more benefit to the manufacturers in term of
using simple molding process that can meet even the complex shapes, which could result in more
creative car designs in the future.
Currently, it is not economic beneficial to use carbon fiber as a car body material comparing to
the current materials. It is more economically to use the current materials for the cars’ bodies.
However, with the increase for the need to develop new cars that will result in reduction of
energy consumption and CO2 footprint, governments with the automobile industry and the
research center should continue the effort to find more efficient ways to produce the carbon fiber
7 Reinforced Plastics.Trek BicycleImplements Carbon Fiber RecyclingProgramme

14. 13
economically that could results in saving of products cost while enhancing the properties of the
products.
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- Carle D., Blount G. (1999). The suitability of aluminium as an alternative materialfor car
bodies. Materials and Design 20, 267-272
- Jambor A., Beyer M. (1997). New cars-new materials. Materials & Design,Vol. 18, Nos.
4r6, pp. 203-209.
- Li Y., Lin Z., Jiang A., Chen G. (2003). Use of high strength steel sheet for lightweight
and crashworthy car body. School of Mechanical Engineering, Shanghai Jiao Tong
University, p.177-182.
- Reinforced Plastics. (2004). Faster production of carbon fibre car parts. Elsevier Ltd.
Volume 48, Issue 9, 18-18
- Reinforced Plastics (2003). Carbon car panels a cost effective reality. Elsevier Science
Ltd. Volume 47, Issue 8, September 2003, Pages 40-42
- Reinforced Plastics. (2011, May). Trek Bicycle Implements Carbon Fiber Recycling
Programme. Elsevier Ltd. Retrieved from the internet.
- Yan X. (2009). Energy demand and greenhouse gas emissions during the production of a
passenger car in China. Energy Conversion and Management, 50, 2964–2966