Krauss Maffei Extrusion, represented in Oceania by HBM Packaging & Plastics Technologies , worked with Wavin to develop a new 36D twin-screw, single venting extruder, which is engineered to process PVC pipe formulations efficiently. The new 36D twin-screw extruder with High Performance Geometry (HPG) reduces process fluctuations during the manufacturing process.
By eliminating atmospheric venting in the extruder, the engineers can use the 36 L/D length of the processing unit for optimal plasticising and homogenising of the PVC resin. The long preheating zone means flexibility for processing a range of formulations.
The process stability is increased by the long metering zone, which provides the capability to build pressure and optimal control of the melt temperature over the whole output zone. The long mixing zone together with optimised element geometry produces homogenous melt and better optical pipe quality. It also improves dispersal of additives and the blowing agent in the melt.The new 36D single-venting technology delivers higher performance in processing U-PVC, M-PVC, foamcore PVC pipe and pipe formulations that call for a high proportion of the chalk filler.