Multiple injection moulding unit

Abstract

An injection moulding unit includes at least two injection moulds for manufacturing disc-like objects. The injection moulds each further include two mould parts which are mutually displaceable between a closed position in which they bound a mould cavity and an opened position in which the disc-like object can be removed. The mould cavity is connected to a pressure line for carrying heated plastic into the mould cavity. A punching means is provided for punching a central hole through the disc-like object. The punching means includes a cylindrical part forming a portion of one of the mould parts and has a leading peripheral edge. The respective pressure lines of the injection moulds are branches of a feed line and together therewith form part of a collective multiple hot runner. The outlet zone of each feed line is configured to couple to an infeed of an injection bush. An outfeed of the injection bush debouches directly into the mould cavity. The hot runner is coupled by a spring device to a connecting piece of thermally conductive material. The connecting piece is fixedly connected to the respective injection bushes. A tempering device is provided to hold the temperature of the connecting piece within predetermined limits.