On-Line Surface Modification of Polypropylene Fibers by Corona Treatment During Melt-Spinning

Abstract

On-line corona treatment of polypropylene (PP) fibers during melt-spinning is studied. After extrusion of pp filaments, collected fiber tow is subjected to corona treatment prior to drawing, crimping, and cutting into staple fibers, and wettability, antistatic, and friction properties of treated fibers are characterized. Corona treatment results in an average decrease of 5-10° in the advancing contact angle and of 10-25° in the receding contact angle for water on fibers. With amounts of spin finish lower than 0.2% by weight of fiber, treated fibers have considerably better antistatic properties than untreated fibers. Treated fibers have an order of magnitude lower electrical resistance and about 50% less static charge build-up during carding than untreated fibers. In addition, there is a sharp change in wetting and friction properties of fibers with corona treatment when the amount of spin finish is between 0.12 and 0.13 wt %. These effects are attributed to improved wetting of the treated fibers by spin finishes, leading to a more uniform spreading of finish agents on the fiber surface.