spritzgiessabdichtungsring with a central axis with the hot top

摘要

This invention relates to a hot tip gated injection molding apparatus having a heated manifold (10) to distribute melt to a number of spaced gates (34). An unheated sealing and conductive member (38) is mounted directly between the heated manifold (10) and the cooled cavity plate (14) in alignment with each gate. The sealing and conductive member (38) has an elongated hot tip shaft (54) which is connected to extend centrally through the bore (56) of an outer collar portion (52) by a number of spaced spiral blades (58). The collar portion (52) bridges an insulative air space (50) between the hot manifold (10) and cooled cavity plate (14) to prevent melt leaking into it. Heat received through the rear end of the collar portion (52) which abuts directly against the heated manifold (10) is transferred through the blades (58) and the hot tip shaft (54) to the gate area which is aligned with the pointed forward end (70) of the hot tip shaft (54). The rear end (68) of the hot tip shaft (54) extends rearwardly into a branch of the melt passage (20) to pick up heat from the surrounding melt. The hot tip shaft (54) has a highly conductive inner portion (72) inside an abrasion resistant outer portion (74) to conduct heat to and away from the gate area during different parts of the injection cycle. The spiral blades (58) impart a swirling motion to the melt which flows between them. IMAGE