Pre-preg

Pre-preg is a term for "pre-impregnated" composite fibres where a material, such as epoxy is already present. These usually take the form of a weave or are uni-directional. They already contain an amount of the matrix material used to bond them together and to other components during manufacture. The resin is only partially cured to allow easy handling, this is call B-Stage material and requires cold storage to prevent complete curing. B-Stage pre-preg is always stored in cooled areas since complete polymerization is most commonly done by heat. Hence, composite structures built of pre-pregs will mostly require an oven or autoclave to finish the complete polymerization.