Composites Flashcards
Describe the manufacturing process of glass reinforced plastic products.
Mould is checked for any defects
Polished with wax to give it a smooth and glossy finish
Thin layer of release agent is added to the mould
Gel coat is applied to the mould – a mixture of resin, pigment and catalyst
When the gel has cured, a layer of glass fibres is laid inside the mould and another layer of polyester resin with a catalyst, which is rolled onto the reinforcing layer
Repeated until the ideal thickness is achieved
Wait for it to fully cure and then remove it from the mould
Tidy it up (sanding edges etc)
What resin is used in the manufacture of composites?
Polyester or Epoxy resin.
GRP Advantages
Corrosion resistant
High strength to weight ratio
Possible to shape into complex forms
Can be finished in a range of colours
GRP Disadvantages
Brittle
Prone to osmosis (water seeps between layers and causes it to delaminate)
Not easy to repair
GRP Uses
Boats, baths, ponds
CFRP Advantages
Corrosion resistant
High strength to weight ratio
Possible to shape into complex forms
Can be finished in a range of colours
Lighter than GRP
CFRP Disadvantages
Brittle (less than GRP)
Prone to osmosis (water seeps between layers and causes it to delaminate)
Not easy to repair
More expensive than GRP
CFRP Uses
Aircraft, boat hulls, car body panels, sports equipment
Kevlar Advantages
High tensile strength
Lightweight
Can be woven - flexible
High toughness
Good shock absorption
Kevlar Disadvantages
Not waterproof
Not UV stable
Kevlar Uses
Body armour, bullet proof jackets
Nomex Advantages
Flame resistant
High thermal stability
Abrasion resistant
High chemical resistance
Electrical insulator
Nomex Disadvantages
More expensive than other flame-resistant fabrics
Nomex Uses
Electrical motors, fire suits
