About Composites

The Composite Advantage

Composites materials offer the designer an exciting new opportunity in engineering and the aesthetic.

Composites offer:

• Low weight leading to high specific stiffness and strength.
• Fibres oriented with the direction of principle stresses for optimal performance.
• Excellent environmental and corrosion resistanceVery low thermal expansion.
• Vibration damping properties.
• Fatigue resistance.
• Complex shapes and one off structures are easily manufactured.
• Simple repair procedures.

The Prepreg Advantage

A prepreg consists of a reinforcement (glass, carbon, aramid etc. in woven, multi-axial or unidirectional form) pre-impregnated with a resin matrix in a controlled ratio and supplied in rolls. Prepregs are fully formulated, reactive systems (no handling or mixing of potentially dangerous chemicals); simply cut it from the roll and laminate.

Prepreg can be easily and accurately positioned on the mould giving a high level of fibre orientation control with no risk of movement, fibre wash out or the development of resin rich areas during subsequent processing which lead to loss of performance.

Cored structures (foam, honeycomb, etc.) are easily produced using complementary film adhesive systems. Much easier and cleaner to handle than wet pastes adhesive films give controlled and consistent bond lines.

Once laminated a prepreg laminate requires:

• Pressure to consolidate.
• Heat to bring about the curing reaction.

Storage

Prepregs should be stored, wrapped and sealed in polythene, at -18°C (0°F) for maximum shelf life. The material must be fully thawed before breaking the polythene seal in order to avoid moisture contamination.

All prepregs have a clearly defined room temperature working life referred to as the out life.

Health and Safety

Prepregs are low-risk in terms of handling hazards However, gloves and protective clothing must be worn when handling them in the workshop.