Temporary and Permanent Fiber-Friction Increases Induced by Corona Treatment

Abstract

"Frictionizing" textile fibers by corona treatment produces larger effects than conventional chemical methods. A marked increase in wool fiber friction occurs, both with and against the scales. For wool, the increase in with-scale fric tion decays slowly with time after treatment; against-scale friction does not. Initial cohesiveness of air-corona treated wool roving increases 230%, but then, reflecting the decay of with-scale single-fiber friction, decreases slowly with time toa residual cohesiveness 32% above that of untreated roving. Residual cohesiveness is responsible for improved wool yarn spinnability and tensile strength. Untreated mohair fiber friction is much less than that of untreated wool, but after corona treatment the friction values become comparable. However, treated mohair differs from treated wool in that its with-scale friction after treatment does not decrease. Increased mohair fiber cohesiveness improves yarn tensile strength 31% Injection of dilute chlorine gas into the reactor greatly reduces the required corona treatment time and indicates the feasihility of high-speed corona processing of mohair. Cotton roving cohesiveness is increased initially by chlorine-corona treatment to four times its original value, but then its cohesiveness diminishes much more rapidly than in the case of wool. The residual cohesiveness increases cotton yarn tensile strength by 24%. It appears that the very high cohesiveness of wool and cotton roving immediately after treat ment, if followed by immediate processing, can be used to further improve spinning beyond that achieved when treatment is followed by delayed processing.