composites

Composite material

A material made from two or more materials combined to produce improved properties.

Bonding in composites

There is no chemical bonds; the materials interact physically to give better performance.

CFRP (Carbon Fibre Reinforced Plastic)

A composite made of carbon fibres and a polymer resin. Used in high-performance sports equipment, cars, and aircraft because it is strong and lightweight.

GRP (Glass Reinforced Plastic)

A composite made of glass fibres and a plastic resin. Used in boats, water slides, and large liquid containers because it is lightweight and waterproof.

Kevlar

A composite made from strong polymer fibres. Extremely tough and impact resistant; used in bulletproof vests, helmets, and protective panels.

Why composites are used

They combine the best properties of each material to make stronger, lighter, or more durable products.

what are composites mostly made out of

matrix - binds or surrounds
reinforcement - the fibre

disadvantages with composites

very difficult of even impossible to recycle

can be expensive to manufacture

modern composites

Carbon fibre reinforced polymers (CFRP)
Glass-fibre reinforced polymer (GRP)
Aramid products (Kevlar)

early composites

combining mud with plant material

advantages of carbon-fibre reinforced polymers (CFRP)

excellent strength to weight ratio
very stiff but light
resistant to corrosion

diadvantages of carbon-fibre reinforced polymers (CFRP)

very expensive compared to other modern composites

features of carbon-fibre reinforced polymers

high tensile carbon fibres as reinforcement
polymer resin as matrix
high heat resistance

where are carbon-fibre reinforced polymers (CFRP) used?

aerospace industry (high heat resistance)
marine, automotive, defence, high performance sports, leisure

advantages of glass-fibre reinforced polymers (GRP)

lightweight but fragile
impermeable and non-corroding to water

what is glass-fibre reinforced polymer also known as

fibreglass

features of glass-fibre reinforced polymer

strands of glass are reinforcement
polyester resin is the matrix

how is glass-fibre reinforced polymer (GRP) made?

glass woven fabric laid into a mould, resin added in layers and left to cure.

where is glass-fibre reinforced polymer (GRP) used?

car bodies, water tanks, swimming pool slides, canoes, boat hulls

advantages of aramid products (kevlar)

stronger than steel
very touch and stiff, does not snap easily
impact resistance, not easily pierced by knives or bullets

features of aramid products (kevlar)

aromatic polyamide threads is reinforcement
resin is matrix

how are aramid products (kevlar) made

chemical reaction when woven into thread

where can aramid products (kevlar) be used

bullet proof vests, personal protective equipment