Experimental Studies for Optimizing Screw and Die Design When Compounding Fiberglass Strand on the Co-Rotating Twin Screw Extruder

Compounding fiberglass strand on a co-rotating twin screw extruder re quires a balance in process (screw and die) design. Certain physical mechanical proper ties, such as notched Izod, mirror preserved glass length while flexural properties are a function of preserved glass length as well as fiber-matrix adhesion. Reduction in glass attrition requires a very mild screw configuration and minimal average shear rate in the extruder and die, while good adhesion is promoted by complete glass wetting requiring an effective mixing screw and die restriction. This article will present the results of a designed experiment and the application of computer-aided modelling techniques in defin ing an optimum twin screw process configuration for fiberglass compounding.