The Benefits of Engineered Fibre Composites
Fibre composites can consist of either glass reinforced plastic (GRP) or Fibre Reinforced Plastic materials such as carbon, aramids (of which one type is Kevlar) or more exotic materials such as boron, or thermoplastic.
The fibres are mixed with a resin which may be polyester, vinylestic, phenobic epoxy or polyveethare depending largely on the mechanical, chemical and temperature properties required.
With this inherent flexibility, fibre composites can be used creatively to provide a range of benefits over mere “traditional” materials. These include:
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Strength to Weight Ratio :
The following table gives a comparison of the material properties of fibre composites and common metals. The higher values of the fibre composites can be exploited to give a structure with the same strength but for lighter. This may be in the order of 3-5 times that of metal.
|
Material Type |
Tensile Modulus
(GPa) |
Tensile Strength
(MPa) |
Density
(g/cm3) |
| Carbon Fibre |
High Strength |
160-270 |
3500 |
1.8 |
|
Intermediate Modulus |
270-325 |
5300 |
1.8 |
|
High Modulus |
325-440 |
3500 |
1.8 |
|
Ultra High Modulus |
440-600 |
2000 |
2.0 |
Kevlar
(Aramid) |
Low Modulus |
60 |
3600 |
1.45 |
|
High Modulus |
120 |
3100 |
1.45 |
|
Ultra High Modulus |
180 |
3400 |
1.47 |
| Glass Fibre |
E-glass |
69 |
2400 |
2.5 |
|
S-glass |
86 |
3450 |
2.5 |
| Aluminium |
|
72 |
400 |
2.7 |
| Titanium |
|
110 |
950 |
4.8 |
| Steel |
Mild |
200 |
450 |
7.2 |
|
High Strength |
200 |
1200 |
7.2 |
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Weight Saving :
By incorporating light weight cores in a structure with the inherent advantages of superior strength to weight of the fibres, designers can achieve significant weight savings in nearly all areas of manufacture. Increasingly fibre composites is gaining popularity in automobiles, caravans, motorhomes, watercraft and aircraft where better performance and reduced fuel consumption is being relised.
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Corrosion Resistance : Resin can be chasen to meet a wide range of chemical resistance requirements and will therefore perform far better than most metak in applications where corrosion is an issue.
Fibre composites have proven to perform extremely well in areas such as chemical storage, processing, salt water environments and fuel storage.
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Form and Function : Because of the ability to form fibre composites in purpose–designed moulds, the materials that can be applied is, 3D shapes where curves, soft corners and aesthetic form is desired. This largely eliminates the need for post machining that normally applies to metals.
Applications can range from airodynamic , hydrodynamic, ergonomic to purely eye-pleasing.
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Low Thermal Conductivity : Composites are good insulators, and make excellent choice for doors, panels and containers that need to keep heat or cold either in or out.
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Low Distortion : Composites have the ability to maintain their shape under varying temperature and humidity. This is particularly important where a tight fit between components is important, such as in an aircraft that regularly endures the effect of high and low altitudes. |
Non-conductive : Fibre composites are inherently non-conductive which opens up an important section of possible markets where electrical safety / insulation is paramount. Conversely, where conductivity is required, additives can be mixed with the resin to give selective conductivity .
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Non Magnetic and EMI Transparent:
Fibre composites are non-magnetic and aectromagnetically transparent. This means that their use is ideal applications where sensitave electrical and computer equipment is needed, eg radar covers in aircraft and ships.
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Radar Transparent : Composites allow radar signal to pass straight through which is one reason the US Air Force is making use of composites in such aircraft as the stealth bomber, or on the ground where radar equipment is operating.
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Part Consolidation : By using a single composite part rather than many metal parts joined together in an assembly, production costs can be greatly reduced, together with the cost of maintenance over the life of the article. |
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