PRODUCTION OF ACRYLIC CARBON FIBER BUNDLE HAVING IMPROVED PROPERTIES

摘要

PURPOSE:To obtain an acrylic carbon fibre bundle having improved mechanical properties, especially tensile strength and elongation, by converting an acrylic fiber bundle to give an oxidized yarn bundle, heating it in an inert atmosphere until it reaches a particular specific gravity. CONSTITUTION:An acrylonitrile polymer fiber bundle is heated in an oxidizing atmosphere at 210-300 deg.C, and converted into an oxidized fibre bundle having =2.8g/d tensile strength, =10% tensile elongation, 1.25-1.38 specific gravity, 3.5-7% equilibrium water content, and low degree of oxidation. This oxidized fiber bundle is heated in an inert atmosphere of nitrogen, argon, etc. having the maximum temperature of =1,200 deg.C at 50-300 deg.C set rate of heating until the specific gravity of the fiber reaches 1.45, it is then heated further in the inert atmosphere so that the specific gravity reaches =1.75, to give the desired acrylic carbon fiber bundle.