Purging mixture for extruder

Abstract

This thesis work focuses on compounding a mechanical purge mixture for extruders. The base resin for making the purge mixture is recycled High Density Polyethylene chosen for its high density and good processing temperature. The additives are mainly clay and sili-con dioxide added as filler and scrubbing materials respectively. The purge mixture was produced by mixing the base resin and additives in percentage ratios into five places la-beled A, B, C, D, and E. the mixtures were extruded and tested for purging effect in comparison to a commercial purge compound, it was observed that the performance of specimen E which contained 87% recycled HDPE, 8.7% clay and 4.3% silicon dioxide had performance near that of the commercial purge compound. The synthesized purge mixture can be applied in extruders for removing resins like Acetal, ASA blends, Fluoro-polymers, Nylon, Polybutylene terephthalate, polycarbonates, Acrylonitrile butadiene sty-rene, PEI, PET, polyester alloys, polyolefins, PPS, PVC and TPE as well as effect color changes in these resins. Although the purge mixture can be used in extruders for purging resins and colors, its effect in other molding machines have not been tested.