Extrusion Asia Edition 1-2025

27 EXTRUSION & RECYCLING ASIA 1/2025 RECYCLING, FILM EXTRUSION ￭ LDPE/LLDPE lm has existing collection systems in many European countries that have been in place for many years to provide this type of material for recycling. As markets demand recycled content in a broader range of applications, a challenge is to produce clear shrink, stretch or blown lm that maintains properties while incorporating recycled content. In this context, new capacities have been built in Eu - rope and worldwide or existing plants have been retro - tted with improved sorting, washing steps or additional melt ltration systems in order to be able to o er high- quality polyethylene (rPE) streams for recycling. How - ever, even LDPE/LLDPE that has undergone extensive mechanical processing, can be di cult to convert into new lm on conventional production lines, which is why the companies Colines, ExxonMobil Signature Polymers and Gneuss have joined forces in a development project to develop a viable lm production process with potential cost savings. In particular, the so-called gels and black dots are dis - ruptive factors that could be minimized with the appropri - ate materials from ExxonMobil Signature Polymers and a pressure-constant screen changer from Gneuss on a highly exible cast lm line from Colines. ExxonMobil Signature Polymers´s technical experts have conducted trials using PCR material (Post Consumer Recycle) derived from stretch lm in combination with Ex - ceed Tough m 3812 high performance polyethylene and observed a reduction in the size of the larger polymer gels. With most of the commercial PCR grades available on the European market today, extrusion lines often cannot run continuously. Continuous ltration can help to run extru - sion lines for longer production periods. Filtration removes a signi cant proportion of the impurities present in the melt, but not all the gels," says Bart Lauwers, Principal Extrusion Customer & Application Development at ExxonMobil Tech - nology Group. Nevertheless, the project has demonstrated quality and process consistency. All tests carried out demonstrated the ability to consistently produce lm that incorporated 30% PCR content for automatic use with a consistency of 180 to 200% without the need to stop the line, except for routine operations unrelated to recyclate use (e.g. lip die cleaning, chill roll cleaning, resin or format changes). A key component in this process was the patented Gne - uss RSFgenius self-cleaning screen changer. This fully au - tomatic ltration system renewed the screen surface with no measurable pressure uctuations and can be adapted to the material in question, with screen nenesses typically ranging from 30 - 75μm, even during full operation. Colines is a renowned manufacturer of cast and blown lm lines based in Novara, Italy. Colines has demonstrat - ed exceptional exibility in meeting the individual needs of its customers. Not only with the full integration of Gneuss screen changers, but also in terms of fully customizable line set-ups for the production of any type of lm. The collaboration between Colines, Gneuss and Exxon - Mobil Signature Polymers has already led to the creation of several large-scale production lines speci cally dedicated to recycled content incorporation with many more in prog - ress for various global markets. Gneuss Kunststo technik GmbH Moenichhusen 42, 32549 Bad Oeynhausen, Germany www.gneuss.com 欧洲采用 Gneuss RSFgenius 过滤系统的生产线 Production line with Gneuss RSFgenius ltration system in Europe RSFgenius 过滤系统在 Colines 技术中心运行 RSFgenius ltration system in operation at Colines’ technical center