IN-MOLD PUNCH APPARATUS AND METHODS.

摘要

A mold (19) is provided for forming a continuously-extruded parison into a corrugated pipe. The mold includes a mold housing having a plurality of bores, a mold cavity having a plurality of annular corrugations (26), and a plurality of punches (30). Each punch is disposed in one of the bores and aligned with one of the annular corrugations of the mold cavity. Each punch is also configured to form an aperture in a corrugation of a corrugated pipe in the mold. A continuous extrusion blow molding system and a method are also provided for forming a hollow plastic product and punching a continuously-extruded, blow molded product before it is released from a mold.