In-line Compounding of Long-fiber Thermoplastics for Injection Molding

A new process has been developed for in-line compounding and injection molding in a single operation. Selected short- to long-fiber-reinforced thermoplastic mixtures are created and fed directly into the injection molding barrel while still hot. Compositions containing glass fibers of 3-12 mm in length have been molded successfully on a 230-ton injection press. The new processing system is adaptable to the existing injection molding machines. This novel technology permits molded articles to be produced at cost levels that are less expensive than those incurred when molding parts from the conventional long- and short-fiber-reinforced thermoplastic compounded pellets.