Extrusion International 5-2021

PREVIEW 56 Extrusion International 5/2021 At Fakuma, plastics distributor DREYPLAS will showcase innovative application possibilities for the ultra-high- molecular-weight polyethylene (UHMWPE) LUBMER™ from Mitsui Chemicals. Compared with conventional sin- tered semi- fi nished products, this offers possibilities for considerable cost savings in the production of moulded parts and pro fi les that also boast excellent surface slip properties. This advantage comes from the thermoplastic processability by injection moulding and extrusion. In this way, it is no problem with Lubmer to produce parts with narrow tolerances and very low depths of roughness. As a result, the amount of time required is signi fi cantly re- duced, and the large quantities of costly, non-reusable production scrap from the machining of semi- fi nished products are no longer produced. In current sampling tri- als at customers, Lubmer has also proved that the product is suitable for 3D printing. The difference between the various UHMWPE types lies in the length of the molecule chains. With conventional types, they are so long that they cannot bemeltedbut have to be sintered into the semi- fi nished products. Compared with that, the molecular weight of the Lubmer types sup- plied in granule form is reduced by just enough for pro- cessing to be possible on conventional injection moulding machines and extruders. As a result, it provides greater DREYPLAS GmbH www.dreyplas.com DREYPLAS B1-1004 design freedom than with the machining of semi- fi nished products and, furthermore, the production scrap – which is less anyway – can be melted again and returned to the process in an environmentally friendly manner. Despite the reduced molecular weight, Lubmer offers, with smooth friction partners such as steel, equally good tribological properties as components made of a sintered semi- fi nished product. This and its recyclability in the polyole fi n stream make it in many applications a sustain- able alternative to engineering plastics such PPS, POM, PA or PBT. Lubmer can be used in applications at long- term temperatures down to –200°C, and its chemical re- sistance, heat resistance and (low-temperature) impact strength are the same as those of UHMWPE semi- fi nished products. It complies with all the REACH regulations and is approved to FDA and EU10/2011 for food-contact ap- plications. Alongside the basic types, namely Lubmer L3000 with the highest fl owability, L4000, and L5000, which is also suitable for extrusion and has the highest abrasion resis- tance, DREYPLAS also markets the higher temperature- resistant Alloy LS4140, which, thanks to its polyamide modi fi cation, combines elevated temperature resistance with good fl ow properties. Lubmer can be used both with hot runner systems and with traditional tunnel gates. The light and opaque intrinsic colour facilitates the use of colour masterbatches. Other functional additives can also be incorporated via the conventional metering systems. Lubmer offers very good sound insulation and better elec- trical insulation properties than most other polyole fi ns. The combination of low sliding friction and high abra- sion resistance also make it an effective alternative for applications such as bearings that are subjected to high stresses, and generally also for technical components that are subjected to sliding friction during use. At the same time, extruded guide elements and pro fi les also offer the typical bene fi ts of UHMWPE. UHMWPE for Injection Moulding, Extrusion and 3D Printing: UHMWPE types in the DREYPLAS portfolio that are suitable for injection moulding, extrusion and 3D printing allow considerable cost savings compared with the machining of semi- fi nished products (© Dreyplas)