Development of a pneumatic spreading system for Kevlar-based SiC-precursor carbon fibre tows

A novel spreading system based upon the Venturi principle was designed and constructed. The system was used to spread Kevlar-based carbon fibres and to maintain that spread for sufficient time to facilitate chemical vapour deposition of an SiC coating. The Kevlar-based carbon fibres were shown to possess excellent thermal stability and a combination of properties that make them an ideal silicon carbide precursor fibre. Through a combination of pinch-rollers and two distinct axial Venturi spreaders, a highly chaotic and effective spread was achieved and maintained. This work provides a novel process for producing potentially excellent silicon carbide precursor fibres as well as providing a novel use for a high-performance polymer.