Process for making fluoropolymer composites

摘要

A process for the production of structural and semi-structural composites formed by compressing planar layers of nonwoven preform materials formed from aqueous blends of reinforcing fibers and thin thermoplastic fluoropolymer flake. The flakes have an irregular periphery with microfibrils extending therefrom, having a Canadian Standard Freeness of from 800 to 883. The planar layers which are unconstrained in the in-plane direction are preconsolidated by heating the layer to above the melting point of the fluoropolymer, the applying pressure normal to the plane of the layer causing the fluoropolymer to flow thus orienting the fibers in the plane of the layer. The composites are useful in applications which require higher strength and/or modulus, and where chemical and/or heat resistance is needed, as in chemical processing.