Spiral-grooved barrel extrudes faster. (Extrusion).

A new extruder concept developed by Eberhard Gruenschloss at the University of Stuttgart, Germany, has been commercialized for extrusion by Extrudex Kunststoffmaschinen GmbH in Muehlacker, Germany. The Helibar is a single-screw extruder with a barrel that is grooved throughout, with deep spiral grooves in the feed section and shallow axial grooves along the rest of the barrel. A 70-mm-diam., 36:1 L/D Helibar with a screw speed of 150 rpm produces 990 lb/hr of PE vs. 500 lb/br for a comparable smooth-bore extruder. Output of the 70-mm, 36:1 Elelibar is similar to that of a 90-mm, 30:1 conventional extruder. Extrudex has built models of 35, 50, and 70 mm and says they can process HDPE, LLDPE, LDPE, PP, PS, acrylic, PET, PC, nylon 6, flexible PVC, EVA, TPU, and other TPEs.

Helibar technology was co-developed by Soplar in Switzerland. Soplar builds extrusion blow molding machines exclusively for the processor Alpla, which wanted a more compact extruder with higher output. Soplar has delivered over 150 Helibar units for blow molding in the past three years, and Extrudex has built a dozen for extrusion, mostly of pipe. Extrudex has signed an exclusive supply agreement with a European injection machine builder, which will produce Helibar extruders for injection molding. Extrudex is looking to license the technology to a builder of extruders. Tel: [phone], www.extrudex.de