Extrusion International 5-2018

PREVIEW 40 Extrusion International 5/2018 Due to their high molecular mass and the resulting viscos- ity, ultra-high molecular weight polyethylenes (UHMW- PE) can only be processed mechanically with a high de- gree of expense. However, the Japanese company Mitsui Chemicals has developed a special UHMW-PE as a granu- late – brand name: LUBMER – which can be turned into a flowing form and can therefore be directly processed in injection moulding or extrusion processes. Costly rework- ing and deburring operations are no longer necessary. Various new applications for UHMW-PE have already been developed in cooperation with the distribution partner DREYPLAS GmbH. The product variants retain their ultra-high-molecular properties even after process- ing and, due to their mouldability, allow for the produc- tion of finished parts in large series. All LUBMER variants will be presented by DREYPLAS at FAKUMA in Friedrich- shafen. “Ultra-high-molecular-weight polyethylene as a powder must first be pressed before the desired components can be mechanically worked out from blocks or ring moulds, all at great expense,” explains Dipl.-Ing. Norbert Hodrius, Product Manager at DREYPLAS GmbH. “Due to their high molecular mass and the resulting high viscosity, these polyethylenes are unsuitable for injection moulding and extrusion in principle.” This is now possible with the LUB- MER-type UHMW-PE: Through changes in the polymer structure, the plastic is adapted in such a way that very good flow properties are achieved. This ensures an even distribution in the injection mould and prevents defects such as surface roughness. However, the basic proper- ties of the plastic, such as its sliding capacity, abrasion resistance and heat deflection temperature, remain un- changed. Thanks to the improved sliding properties, more finished parts can be produced in series from this durable plastic: Several components can be injection moulded from one mould with short cycle times using multi-cavity tools. Post-processing or chippings, as is the case when using UHMW-PE semi-finished products, are eliminated. De- spite the special production process, the variants L3000, L4000 and L5000 have a very high wear resistance and im- pact durability, whereby the L5000 is especially suitable for extrusion. They also behave like standard polyolefins, which is evident in their favourable chemical resistance and electrical properties. “We offer comprehensive tech- nical advice as well as laboratory analyses prior to project planning,” adds Hodrius. The customers benefit from the distributor’s experience. DREYPLAS offers its customers not only logistics and quality-tested goods but also just- in-time delivery and worldwide access to high-perfor- mance polymers and additives. DREYPLAS Unique UHMW-PE can be processed directly in injection moulding and extrusion DREYPLAS GmbH www.dreyplas.com Hall B1, Booth 1004 There is now a UHMW-PE suitable for injection moulding thanks to LUBMER: The ultra-high molecular properties of the plastic as well as its abrasion resistance and heat deflection temperature are comparable to those of conventional UHMW-PE