What are Composites?

Composite materials comprise fibres held together
by a polymer resin .....

..... creating a combination which is
greater than the sum of the two parts!

Thermoplastic composites showing variety of weave patterns and fibre types, giving rise to range of properties.

Foam core cut-out used to enhance sound attenuation and sectional stiffness.

Thermoset and thermoplastic

All composites consist of fibres, which are may be carbon, glass or Kevlar®, plus a polymer matrix which bond the fibres together. There two two main groups of polymer - thermoset and thermoplastic. Thermoset cure and harden with the application of heat whilst thermoplastic soften and become pliable on the application of heat.

In general thermoset composites are used for components with a complex shape and where the production volume is low. Thermoplastic composites are generally suited to simple shapes and high volume with fully automatic production methods. Thermoplastic composites can be re-cycled by grinding to be reused for injection moulding. Therefore there is no material scrap.

At C2 Composites, we use prepreg materials. These consist of fibres which are pre impregnated with a resin system, which means that the overall quality and performance is highly controlled and consistent.

Fibre choices

It is the fibres which provide strength and stiffness and dominate the physical characteristics of the composite. The fibres may be laid up in varying directions within a component, to control the stiffness and rigidity. By changing and combining the type of fibre, direction and quantity, it is possible to control material characteristics very precisely with excellent reproducibility.

The choice of fibre type is governed by such factors as strength, stiffness, impact resistance and cost.

Polymer matrix choices

All composite materials are lightweight due to the intrinsicc properties of the fibres and polymers being used. Different polymers further enhance the basic properties of strength, thermal and electrical conductivity and sound insulation. Most are totally inert and so are ideal for adverse environmental conditions, such as seawater, oil and corrosive fluids. Resins may be optimised to withstand a wide range of operating temperatures, from cryogenic to a practical maximum of 250°C.

Thermoset material suppliers

Thermoplastic material suppliers

Maintained by Mr. Andrew Commander © 2001.