Glass Fibre made by ‘laying up’.

Glass is spun to produce a fibre, then coated to aid bonding to the resin.

The fibres of glass are available in a variety of thicknesses (from coarse to very thin).

The Polyester Resin is quite brittle on its own, Glass fibres are relatively useless without the resin. 

The composite material is called Glass Reinforced Plastic or GRP.

A mould is required for GRP and these can be produced quite cheaply but their surface can often affect the final quality of the GRP shell.

Carbon Fibre Reinforced Polymer (CFRP) became popular in the production of F1 car bodies, tennis racquets and other performance equipment. One more usable example is medicine - prostheses.

Carbon fibres are woven into a matt which is cut to shape. This is what gives carbon fibre its distinctive (individual) look.

This is then placed in a mould where it is impregnated (saturated) with resin and forced into shape.

The mould parts are then baked at 170 degrees Celsius for up to 8 hours to promote the rigid cross links in the resin.

Kevlar is a mixture of aromatic and aramid (Nylon-like) molecules melted together and spun into fibres. 

This material has a very high strength and, weight for weight, is five times stronger than Steel but half the density of Fibreglass. It has high chemical resistance and high cut resistance as well as being flame resistant.

It has various uses:

• body protection, armour and helmets.

• sports equipment

• sails for windsurfing

• run flat tyres that will not damage the rim

• gloves for use with glass and sheet metal.

Concrete is made up of materials known as aggregates, like sand and cement. Concrete is mixed when dry, water is then added and it is mixed thoroughly. Concrete reinforced with glass fibres to make glass reinforced concrete (GRC). This also allows it to be cast into more complex shapes as the glass fibres replace the need for aggregate such as gravel and stone.

It has various properties:

• Can be moulded into complex shapes.

• Similar properties to stone.

• Components are more readily (easily) extracted than stone.

• It has excellent compressive strength, it is good in building and for their foundations.

• However, it is poor in tension making it necessary to reinforce the concrete beams with metal rods when spanning large distances.

Cermets are a mixture of both metal and ceramic particles. The ceramic Tungsten combined with the metal Cobalt. This material is used extensively for cutting tools as it keeps its edge well.

Another cermet is aluminium oxide and cobalt used in jet engines.

Cermets are resistant to high temperatures and are very tough and shock resistant.

An example of this is ALU composite. This material is a laminate of around 0.3 mm Aluminium sheet sandwiching a Polyethylene core. The overall thickness is about 3mm.

This results in a lightweight material that has excellent rigidity along with good impact resistance. It can be drilled, sawn and can be rolled or bent into shape. It is used in vehicle skins for its reduced weight and noise reduction. It is also used for partitions and in boats.