Composites Flashcards
What is a composite
When two or more materials are bonded together to improve functional, aesthetic and mechanical properties such as better strength to weight ratio
What are Glass re-enforced plastic and where they used?
Polyester + Epoxy Resin + glass fibres to strengthen in matting
Glass fibres create a basic structure as the resin bonds the fibres together
Resin is hardened by catalyst
One side is rough ( glass matting) and one side is smooth due to gel coat
Boats, blades on wind turbines
What are the advantages of glass re-enforced plastics?
What are the disadvantages of glass re-enforced plastics?
Has a strong tensile and compressive strength Extremely lightweight Waster proof Resists corrosion Repaired easily Variety of colours Very expensive High quality mould needed Specialised manufacturing process required
What is carbon fibre and where they used?
Strands of carbon fibre filament are criss-crossed over each other
Several layers increases strength in compression
Layer of resin on top to provide good finish and helps to support fibres
Sports equiptment, car body panels
What are the advantages of carbon fibre?
What are the disadvantages of carbon fibre?
Good strength to eight ratio Good tensile strength Can be formed into many shapes Stronger than most metals Extremely expensive Cannot be easily repaired Only available in black Specialised manufacturing process involved Mould needed Cannot be easily recycled
What is MDF and where they used?
It is medium density fibre board
When waste soft woods are cut into wood chips
These are put through heat and pressure to soften fibres
Pulp is created and mixed with a resin adhesive which bond fibres
Cooled, trimmed and sanded to give a smooth finish
Flat pack furniture
What are the advantages MDF?
What are the disadvantages of MDF?
No grain to work with- won’t split and consistent strength
Less expensive
Makes use of waste wood
Available in large sheets
Heavy due to resin
Swells and breaks when waterlogged
Will dull blade than any other wood
Will warp or expand
Requires a specific surface finish to seal fibres
Extremely damaging to health due to amount of dust can cause irritation and respiratory equipment is needed
