Carbon Fibre and GFRP Flashcards
How is carbon fibre made?
To produce carbon fibre, the carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fibre as the crystal alignment gives the fibre a high strength-to-volume ratio. Several thousand carbon fibre bundles are bonded together. It can then be used by itself or bonded in a fabric. It is about 5-10 micrometers in diameter and composed mostly of carbon atoms.
What are the advantages of carbon fibre?
- High stiffness
- High tensile strength
- Low weight
- High chemical resistance
- High temperature tolerance
- Low thermal expansion
What are the disadvantages of carbon fibre?
- It is relatively expensive when compared with similar fibres like glass fibres or plastic fibres. This is because it is not easily mass produced
- This means in the automotive industry it use is limited to racing cars
What are the uses of carbon fibre?
- Major impact on sports equipment because its strength to weight ratio helps improve performance
- Efficiency of aircraft has been improved because of the weight production.
- bike or cars
- It has been made popular in aerospace, civil engineering, military and motorsports, along with other competition sports
What are the mechanical properties of GFRP?
- Strength - GFRP has tensile, compressive and shear strengths that rival or exceed those of traditional materials like steel. It high strength allows for the design if lightweight yet robust structures.
- Stiffness - GFRP has a high modulus of elasticity, making it exceptionally stiff. This is crucial for maintaining structural integrity and minimising deflection under loads.
- Despite its stiffness it exhibits a degree of flexibility. This can be engineered to suit the specific requirements of different applications.
- Fatigue strength - It shows a good resistance to cyclic loading , meaning it can endure repeated stress cycles without failure.
What are the physical properties of GFRP?
- It is a low density material, which contributes to its lightweight nature .
- It is a poor conductor of heat, which therefore makes it a really good thermal insulator.
- GFRP is an excellent electrical insulator preventing the conduction of electricity making it brilliant for certain applications
- It is generally resistant to water absorption and various chemicals. However long term exposure to certain chemicals or UV radiation can lead degrading of the resin matrix
- GFRP has a low coefficient of thermal expansion compared to metals, meaning it doesn’t expand or contract significantly with temperature changes. This can make it suitable for high precision applications.
- It can be made to be opaque or transparent depending on the application
- The adhesion between fibres can be made strong or weak depending on the intended application
What are the advantages of GFRP?
- It has a high strength-to-weight ratio offering excellent structural performance while still being very light. It allows for innovative and cost effective designs in construction aerospace and other fields.
- Corrosion resistance - this may make it particularly valuable in marine, chemical and coastal environments. The longevity and low maintenance requirements contribute to cost savings over time, as they require fewer repairs and replacements.
- It is a very good electrical insulator making it crucial for electrical enclosures, cable trays, and other applications where preventing electrical conduction is essential.
- It is also a very good thermal insulator, this really helps it regulate temperature making it a good choice for applications where thermal control is essential. This may also increase the efficiency properties by reducing the transfer go heat and cold.
What is the GFRP lay up process?
- First, fabrics or mats are cut to size. The resin ( polyester, vinyl ester or epoxy) is mixed with a catalyst other than hardener.
- The mould is coated with a release agent for easy part removal.
- First a thin resin layer is applied to the mould. Then, layers of glass fibre are added and saturated with resin.
- More glass fibre layers are added, with pressure applied to remove air and ensure full saturation.
- The resin is cured at room temperature or with heat (60°C to 80°C) for several hours to harden
- Once cured the part is removed for the mould and trimmed.
- This part may be sanded, painted or coated to improve the aesthetics
What is Glass Fibre Reinforcement Plastic (GFRP)?
GFRP, can also be called fiberglass, is a composite material made by embedding glass fibres in a plastic resin matrix. These glass fibres provide strength and durability while the plastic resin binds the fibers together and offers shape, flexibility and resistance to environmental factors like corrosion
What are the uses of GFRP?
It can be used for infrastructure, for example with
- bridges
- tunnels and roads
- marine structures
- industrial uses
It is even used for:
- wind turbine blades
- medical facilities
- food processing.
How is GFRP made in mass production? ( not sure if I need to know this)
There is more than one different ways of making GFRP: here is one method:
- Materials must be carefully weighed in exact quantities and thoroughly mixed. More than half the mix is silica sand, which is a basic building block of any glass.
- A pneumatic conveyor sends the mixture to a high temperature (1400°C) furnace for melting. The furnace is typically divided into three sections with channels that aid glass flow. The first section receives the batch where melting occurs and uniformity is increased, ensuring that no bubbles are formed. The high temperature makes sure that the sand and other ingredients dissolve into molten glass. The molten glass then flows into the refiner, where its temperature is reduced to 1370ºC.
- Fiberisation involves a combination of extrusion and attenuation, where the molten glass is drawn out into thin fibres.
- To enhance the adhesion between the glass fibers and the polymer resin matrix, a sizing compound is applied. This compound also serves as a protective layer.
- Finally the diced filaments are collected together into a bundle, forming a glass strand composed of 51 to 1624 filaments. The strand is wound into a drum into a firming package that resembles a spool of thread. The firming package still wet from water cooling and sizing are then dried in an oven. - - - Then they are ready to be packaged and shipped or maybe further processing.
