INJECTION MOLDING OF POLYCARBONATE THICK-WALLED PARTS USING A TOOL WITH VARIOUSLY DESIGNED GATE INSERTS

Injection molding is an advantageous technology for the mass production of plastic parts without the necessity for additional procedures. The applicability of this method is still partially limited by the required properties of the manufactured parts. Especially in the field of optics, there is a need to produce thick-walled parts while maintaining their transparency. This paper reports on how various shapes of gating systems affected the process parameters and cavity filling during the injection molding of polycarbonate thick-walled specimens. These outcomes demonstrated that film gates and their alternatives are more suitable for the standard injection molding of thick-walled optical products than the triple-edge gating systems. Favorable results were observed particularly in the uniformity of cavity filling, size of shrinkage, and in the occurrence of defects such as voids or sink marks.