METHODS FOR MAKING FIBER REINFORCED POLYSTYRENE COMPOSITES

摘要

The present invention is directed generally processes for making fiber reinforced polystyrene compositions including from 5 to 50 wt% organic fiber, and from 0 to 60 wt% inorganic filler in a matrix of an atactic polystyrene based polymer. The process includes extrusion compounding the atactic polystyrene based polymer, the organic fiber, and the inorganic filler to form a fiber reinforced polystyrene resin, which is subsequently molded to form an article with a flexural modulus of at least 350,000 psi, and that exhibits ductility during instrumented impact testing. Extrusion compounding processes whereby the organic fiber is continuously fed to the extruder hopper by unwinding from one or more spools, and uniformly dispersing the fiber in the composites via twin screws having a combination of conveying and kneading elements are also disclosed. The extrusion compounding process and the molding process may also be fluidly coupled to provide an in-line compounding and molding process for producing the fiber reinforced polystyrene composites. Colored fiber may also be optionally incorporated into the process to yield articles with a cloth-like appearance. The processes for making fiber reinforced polystyrene compositions are suitable for making molded articles including, but not limited to, household appliances, automotive parts, and boat hulls.