Marc Alvin Lim – 10813586 March 24, 2011 Section EI CIVMATL CARBON – FIBER REINFORCEMENT I. INTRODUCTION Brief History Carbon-fiber was invented by the famous scientist named Thomas Edison in the late 1800s. Though the early fibers didn’t have the same tensile strength as they do today, he used it as filament for the early light bulbs due to its ability to endure or tolerate heat and was ideal for conducting electricity. Also, unlike the materials used today to make these fibers such as the petroleum-based precursor, Thomas Edison’s fibers were made out of cellulose-based materials such as bamboos, cottons, etc. wherein carbonization takes place when the bamboo that is used is heated and baked to very high-temperatures in a controlled atmosphere. This heating method is known as pyrolysis wherein the products of such methods are capable of resisting fire and enduring high temperatures of heat. (HJ3, 2008) It was around the late 1950s that the high tensile strength of these carbon-fibers was discovered and used. It was later on that the materials used were replaced by polyacrylonitrile (PAN) and pitch which were found to be more effective than the old materials. (HJ3, 2008) The modern type of carbon-fiber is somewhat similar to steel with respect to its tensile strength but weighs a whole lot lighter than that of steel. Carbon-fiber weighs only a fraction of the weight of steel but still retains the same tensile strength of steel or in some cases, even higher strengths. Also, another important attribute of carbon-fiber is its inelasticity wherein it plays an important role in reinforcing rigid structures. (HJ3, 2008) That being said, its elasticity can still be
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Marc Alvin Lim – 10813586 March 24, 2011
Section EI CIVMATL
CARBON – FIBER REINFORCEMENT
I. INTRODUCTION
Brief History
Carbon-fiber was invented by the famous scientist named Thomas Edison in the late 1800s.
Though the early fibers didn’t have the same tensile strength as they do today, he used it as filament for the
early light bulbs due to its ability to endure or tolerate heat and was ideal for conducting electricity. Also,
unlike the materials used today to make these fibers such as the petroleum-based precursor, Thomas
Edison’s fibers were made out of cellulose-based materials such as bamboos, cottons, etc. wherein
carbonization takes place when the bamboo that is used is heated and baked to very high-temperatures in a
controlled atmosphere. This heating method is known as pyrolysis wherein the products of such methods
are capable of resisting fire and enduring high temperatures of heat. (HJ3, 2008)
It was around the late 1950s that the high tensile strength of these carbon-fibers was discovered
and used. It was later on that the materials used were replaced by polyacrylonitrile (PAN) and pitch which
were found to be more effective than the old materials. (HJ3, 2008)
The modern type of carbon-fiber is somewhat similar to steel with respect to its tensile strength
but weighs a whole lot lighter than that of steel. Carbon-fiber weighs only a fraction of the weight of steel
but still retains the same tensile strength of steel or in some cases, even higher strengths. Also, another
important attribute of carbon-fiber is its inelasticity wherein it plays an important role in reinforcing rigid
structures. (HJ3, 2008) That being said, its elasticity can still be changed by making a few adjustments
making the carbon-fiber more elastic or inelastic depending on the desired properties.
General Use/Purpose
Carbon-fibers are derived from two precursor materials: (1) PITCH (2) and PAN.
PITCH based carbon-fibers are stiffer and they also have a higher thermal and electrical
conductivity. Although they are found to be stiffer than that of the PAN based, the PAN based carbon-
fibers are the ones mostly used in the fields of Civil Engineering, Aerospace applications, sporting
equipments, automotive, etc. simply because PITCH based have mechanical properties which are found to
be lower than that of the PAN based. PAN based carbon-fibers have high tensile strength whereas the
PITCH based only have fair to good tensile strength. (Kelly, 2011)
Carbon-fiber is usually used in aerospace, civil engineering, military and motorsports. This is due
to its low density resulting to its light weight, strength similar or even greater than steel, and its low thermal
expansion. It is used in many different purposes since by simply altering its weave patterns and placing in
more layers of carbon-fiber it can be made stronger and stiffer for certain purposes such as safety.
It is also very useful to motorsports such as in F1 racing, kayak racing, bicycle racing, etc. because
of its light weight wherein it uses up less fuel or less energy making it fuel efficient and making it less
heavy thus less energy is needed for the locomotives to move and making them move a whole lot faster.
(Discovery Communications, 2011)
Figure 1.0 – Car made of Carbon fiber components (Discovery Communications, 2011)
Recent studies and experiments now also tell us that it can be used in music instruments such as
the violin, guitar and cello. In the past the music instruments would regularly be made up of wood but in
other foreign countries carbon-fiber is now being used as its main component – the body, knobs, etc
excluding of course the strings which are still made up of their regular components and properties. Other
applications include the use of carbon-fiber in laptops, baseball bats, tennis and badminton racquets, etc.
(Illstreet, 2009)
Figure 1.1 – Sony VAIO Laptop made of Carbon Fiber (HardwareSphere,
2011)
Figure 1.2 – Baseball Bat made of Carbon Fiber (Youtube, 2011)
Figure 1.3 – Cello made of Carbon Fiber (Youtube, 2011)
Generally, carbon-fiber is a very versatile material wherein it can be used in many fields and
purposes depending on how people would use it. The uses of carbon-fiber are not limited to the things
mentioned early. In the future, it will be more widely spread and used and might even replace the steel
material that we use today.
Other Carbon-Fiber Products and Usage:
Types Specifications Major Usage
Filament A yarn constituted of numerous number of
fiber: twisted, untwisted, twisted-and-
untwisted
Resin reinforcement material for CFRP,
CFRTP or C/C composites, having such usage
as Aircraft/Aerospace equipment, sporting
goods and industrial equipment parts
Staple Yarn A yarn made of spinning of staples Heat Insulator, Anti-friction material, C/C
composite parts
Woven
Fabric
A woven sheet made of filament or staple
yarn
Resin reinforcement material for CFRP,
CFRTP or C/C composites, having such usage
as Aircraft/Aerospace equipment, sporting
goods and industrial equipment parts
Braid A braided yarn made of filament or tow Resin reinforcement material particularly
suitable for reinforcement of tubular products
Chopped
Fiber
A chopped fiber made of sized or non-
sized fiber
Compounded into plastics/resins or portland
cement to improve mechanical performances,
abrasion characteristic, electric conductivity
and heat resistance
Milled Powder made by milling fiber in a ball-
mill etc.
Compounded into plastics/resins or rubber to
improve mechanical performances, abrasion
characteristic, electric conductivity and heat
resistance
Felt, Mat A felt or mat made by layering up of staple
by carding etc. then needle-punched or
strengthened by organic binders
Heat insulator, base material for molded heat
insulator, protective layer for heat resistance
and base material for corrosion-resisting filter
Compounds A material for injection moulding etc.
made of mixture of thermo-plastics or
thermo-setting resins added by various
additives and chopped fiber and then being
compounded
Housing etc. of OA equipment taking
advantages of electric conductivity, rigidity
and lightness in weight
Table 1.0 – Carbon Fiber Products and Usage (JCMA, 2009)