DEVICE FOR PRODUCING PLASTIC PIPES

摘要

A plastic pipe die head is followed by a calibrating station(3) with a calibrating die comprising groups of lamellae(40) spaced around the periphery of the extruded pipe in the production direction. Gaps between the adjacent lamellae rims(42) of one lamellae group contacting the pipe are covered by the offset rims(43) of the following group of lamellae. An Independent claim is made for a plastic pipe producing plant with a variable extrusion die head at the outlet of which is a vacuum suction cover for controlling the pipe wall thickness. The pipe diameter is accurately controlled at the following calibration station(3) and in a vacuum calibration bath the pipe is cooled and solidified before leaving the bath via a vacuum seal which automatically adjusts to the pipe diameter.