Uberdruck-Aussenkalibriervorrichtung

摘要

An overpressure external sizing tool for extruded hollow profiles of thermoplastic material is described which consists of a sizing bushing which is cooled by a liquid and firmly mounted on the front side, facing the extruder, of a cooling trough, and of draw plates arranged on guiding means within the cooling trough so that they can be longitudinally shifted. The draw plates are provided with individual connections for a cooling liquid and with bores opening into enlarged cross-sections of the draw plate apertures for allowing the cooling liquid to immediately contact the hollow profile as it proceeds through the sizing arrangement. The arrangement permits to fully use the throughput capacity of modern extruders while enabling easy access to the individual stations while starting up the extrusion.