Small-scale heat-treatment of rayon precursors for stress-graphitization

Abstract

A method for the routine stabilization and heat-treatment of rayons to prepare them for carbonization and graphitization has been developed. After treatment by this method, which employs either air or pure oxygen, the yarn is suitable for fast, continuous stress-carbonization and stress-graphitization. Routine processing conditions yield “carbon fibres” with a filament modulus of fifty million psi. This procedure, which produces a carbon yield between 16 and 21 %, has been successfully applied to rayons produced by five different manufacturers. The steps necessary to accommodate the process to different sources of precursor materials are discussed, and the final product properties obtained are presented.