Thermoplastic injection molding process for inclusion of additives uses a compounder with a larger free space at the output end which is only filled during injection of compounded melt into a tool

摘要

Additives are mixed into thermoplastic melt in a compounder and the filled melt injected into a tool cavity by a piston injection unit. During compounding the free space at the output area of the compounder is only partly filled with thermoplastic melt and is only completely filled during the period when the molding cavities are filled by the piston. AN Independent claim is included for the process plant including a piston injection unit and a compounder whose output end of the screw has a profile with a greater volume than in the plasticizing and mixing zone.