Extrusion International 6-2020

35 Extrusion International 6/2020 A German extruder manufacturer has optimised the extrusion Screws with a new patented geometry (IF- Screw® technology) for twin-screw extruders with counter-rotating screws bringing a new momentum to the thermoplastics industries. With the so-called helical screws or IF-screws (interference) Weber have developed a new generation of extrusion screw that provides more cost-ef fi cient extrusion for plastics processing companies. This new screw concept is characterised by higher output, reduced raw ma- terial costs and improved product quality. The new screw technology enables processing methods that could not previously have been fully implemented and in somecases not at all using conventional twin-screw extruders with counter rotating screws. The patented screw design also provides new opportunities for pelletising of shear-sensitive mate- rials with high requirements of ho- mogeneity and proper dispersion. A perfect helix for high-capacity twin screw extruders as compared to conventional screw designs in twin- screw extruders, the helical screw channels feature a helical shape cir- cumferentially. This results in a curvi- linear motion of the screw PVC- fi lled C-chamber. Exposed to intermittent load, this plasticising effect gener- ates additional internal friction be- tween the PVC grains and acceler- This has huge potential for energy saving. In general, an extrusion company will notice the bene fi t of savings in terms of the mixing du- ration and feedstock/ energy costs. Customisation right from the start, Weber develops tailored solutions with consideration of the material properties jointly with customers. All the solutions are based on Ger- man engineering ingenuity coupled with extensive experience in the fi eld of production process and machinery. Our family enterprise has been committed to quality and reliability since 1992. Weber offers comprehensive services and focuses on a long term partnerships with customers. Among our main advan- tages are a customised approach, quick response and availability of spare parts, including those for older models which are no longer in our product range. “Our mod- ernisation service includes advising and offering optimised solutions to increase the capacity of the operat- ing Weber machines by retro fi tting. According to our vast experience, modernisation of a production line is way more ef fi cient than replac- ing it. Thus, we adhere to the sus- tainability concept,” concludes Dr. Markus Weber. Hans Weber Maschinenfabrik GmbH Bamberger Str. 20, 96317 Kronach, Germany www.hansweber.de EXTRUSION TECHNOLOGIES New Extrusion Equipment Standards The patented helical screws by Hans Weber Maschinenfabrik offers both performance and economic bene fi ts for plastics processing companies who are focusing on PVC extrusion. These companies face such challenges as new product ideas, consumer resistance to PVC products, and continuing demand for product quality; it is especially true for PVC materials with a high content of fi ller agents and reinforcing materials, ground products, recycled materials, wood-plastic composites, and peroxide cross-linked polyethylene (for example, PEX-a pipes) ates the transfer of more mechanical energy to the polymer material. The performance of this innovative methodwas fi eld-proven repeatedly over the past years. “The point is that screws which are manufactured un- der the IF-Screw technology enable the transfer of 30% of additional energy to the material as compared to using conventional screw design” underlines Dr. Markus Weber, CEO of Hans Weber Maschinenfabrik. The critical advantages of the pat- ented helical IF-Screw® technology are capacity increase, higher prod- uct quality, lower material costs even when materials with a high content of fi ller agents or recycla- tes are used. Besides this, the screw enables capacity increase without increasing the L/D ratio. Both very low and very high screw speeds en- sure good plasticisation. Thus, the extruder utilisation and fl exibility increases. “The prevailing opinion that “longer is better” can now be dispelled. The helical screw chan- nels increase the effective length by approximately 15%, while the L/D ratio remains the same. We man- aged to increase capacity by 25% for PEXa processing,” says Rainer Vießmann, the Senior Process En- gineer responsible for innovations at Weber. Good homogenisation resulting from the screw design also provides high performance for the processing of dry cold mixtures.