BLOWN FILM High specific outputs, excellent mixing and low melt temperatures should be your expectation for blown film extrusion. Building on the largest installed base of PE Barrier screws, further developments of the DSB design are now available. Newly enhanced versions of DSB II and III in addition to specific models for the newest applications in blown film. Superior mixing results through the application of a variety of mixing devices including the traditional maddock mixers, multiple mixers and cavity transfer mixers (CTM). Second Metering First Metering Barrier Lead Primary Lead Barrier Section Barrier Clearance Melt Channel Barrier Flight Solids Channel Primary Flight Feed Section

BARRIER TECHNOLOGY The DSB barrier screw typically consists of feed, barrier and metering sections with a dispersive or distributive mixer. This design introduces an additional flight over the transition section of the screw known as the barrier flight. This is advantageous because: ■ The barrier flight creates a physical barrier between the solid bed and the melt pool, so that the depth of each channel varies independently. ■ The barrier flight is undercut to allow molten material to pass from the solids channel (S/C) to the melt channel (M/C). ■ The melt channel becomes progressively wider...