High-pressure composite materials
High-pressure composite materials are structural materials which consist of 2 components - a reinforcement material and a thermosetting resin system. The two components are cured under pressure at a high temperature into the finished composite material.
The reinforcement material can be paper, polyester fabric, cotton fabric, glass fabric or glass fibre matting. Reinforcement materials such as carbon fibre, aramide fibre or hybrid materials can also be used.
Resin systems can be based on phenol, melamine, silicone, epoxy, polyester or polyimide.
In the first phase of production, the reinforcement material is impregnated with the selected resin system. The result is an impregnated material, a prepreg. Upon curing under high temperature and high pressure, the individual layers of prepreg are bonded together into a rigid and homogeneous structural material.
Reinforcement materials and resin systems can be combined individually. In this manner materials can be constructed with very specific properties, making it attractive to select high-pressure composite materials in preference to other structural materials.
High-pressure composites have stable geometry at high temperatures and have minimal deformation when subjected to loads. In addition, they have a high strength/weight ratio (the relative weight is approx. 1/5 that of steel and 1/2 that of aluminium) - and also important to note is that they have properties which do not deteriorate with age.
From their original application as insulating materials in electrotechnical designs, modern composites have spread to a large number of other industries, including the transport and aerospace industries.