New screw design enhances pipe extrusion

The new 36D twin-screw, single-venting extruders developed by KraussMaffei Berstorff are tailored for the processing of PVC pipe formulations more efficiently. The high performance geometry (HPG) screw concept provides customers many advantages. By removing atmospheric venting in the parallel twin-screw extruders, the company's engineers were allowed to use the complete 36 L/D length of the processing unit for optimal plasticising and homogenising of the PVC resin. The new extruder design, in relation to the customised HPG screw concept, provides processors significant benefits. The longer effective pre-heating zone gives more flexibility for processing many formulations. Throughput achieves 10% higher compared to double-venting extruders. A longer metering zone means a more stable process because of the improved capability to build pressure and optimal control of the melt temperature over the whole output zone. The longer mixing zone, along with optimised mixing element geometry creates a more homogenous melt and excellent optical pipe quality. It also enhances dispersal of additives and blowing agent in the melt. KraussMaffei Berstorff GmbH Tel: +49-511 5702 397 Fax: +49-511 5702 416 E-mail: rehmetp@berstorff.de Website: www.berstorff.deNike Tiempo Legend