Extrusion Asia Edition 1-2023

55 Extrusion Asia Edition 1/2023 在真空下在挤出机的多旋转脱挥部分高效可靠地提取水分和纺 丝油。KTDI也对这一参考非常感兴趣。 KTDI认为MRS挤出机的脱挥性能也等同于良好的去污性 能。消费后PET瓶片可以回收用于食品接触应用，符合FDA / EFSA标准。因此，挤出机上制造的颗粒/切片可用于食品接触 应用。 为了完善包装，KTDI还指定了格诺斯RSFgenius熔体过 滤系统。该系统是自清洁的，即使在处理消费后PET瓶片时遇 到的相对较高的污染负荷下，也能提供非常精细的过滤。KT- DI的重点是制造需要精细过滤的高质量纤维的颗粒/切片。格 诺斯RSFgenius熔体过滤系统提供了这种可能性，而不会在过 程中造成干扰，并且滤网片更换间隔较长。 在KTDI将PET回收到纤维级质量的格诺斯生产线引起了 人们的兴趣，并在韩国电视上播放。 K TDI has a large technical centre which is open to the public and for general use. It is especially attractive to small and medium enterprises as they can run trials on the equipment at the KTDI technical centre, without having to invest in the equip- ment themselves. With the increasing emphasis on sustainability, more and more fiber manufacturers are looking for ways of using recycled ma- terial for making fibers, whether it be recycling post-consumer PET bottle flake to high quality yarn, or recycling PET fiber waste from fiber production. For use in its technical centre, KTDI decided to buy a Gneuss MRS 70 Extruder, with dosing feeders, vacuum system, auto- matic Melt Filtration System and Online Viscometer for proces- sing PET waste to pellets, with fiber spinning in mind. With the MRS extruder, it is possible to process PET waste directly to fibers but for a pilot line, the intermediate stage of processing to pel- lets/chip gives more flexibility. KTDI were attracted to the Gneuss MRS extrusion system for several reasons When processing post-consumer PET bottle flake to pellets (chip) for yarn manufacture, the MRS extruder offers the opportunity ➠ Gneuss Kunststofftechnik GmbH Mönichhusen 42, 32549 Bad Oeynhausen, Germany www.gneuss.com to adjust the viscosity of the PET by means of the vacuum. The MRS extruder can be fed with undried PET bottle flake and the moisture is extracted under vacuum in the multi rotation section of the extruder. The depth of the vacuum determines how much moisture is removed and how much effect hydrolysis has on the viscosity of the PET melt as it comes from the extruder. Using the reading from the Online Viscometer, KTDI can adjust the vacuum level to give exactly the required IV which can vary considerably depending on the application of the fibers (textile or technical grades). The automatic viscosity control can even automatically vary the vacuum depth in order to maintain the set viscosity. A consistent viscosity is important when high qua- lity fibers are manufactured. The Gneuss Online Viscometer VIS provides accurate, reliable and repeatable real time measure- ment of the dynamic viscosity. Another feature which influenced KTDI s decision in favour of the Gneuss MRS extruder was the ability to process PET post-in- dustrial fiber waste, which has both a high residual moisture level and is coated with spin finish oils. This fiber waste is noto- riously difficult to recycle. Already in 2011, Mogilev Khimvolokno in Belarus pioneered the processing of agglomerated wet, spin finish oil treated PET in- dustrial fiber waste with the MRS extruder. This very successful application of the MRS extruder showed how both the moisture and the spin finish oils could be efficiently and reliably extracted under vacuum in the multi rotation devolatilising section of the extruder. This reference was also of great interest for KTDI. KTDI saw it as bonus, that the devolatilization performance of the MRS extruder also equates to good decontamination per- formance. Post-consumer PET bottle flake can be recycled for food contact applications to FDA / EFSA standards. Conse- quently, the pellets / chip made on the extruder can be used for food contact applications. To round off the package, KTDI also specified the Gneuss RSF- genius Melt Filtration System. This system is self-cleaning and offers the possibility of very fine filtration even with the relatively high contamination loads which are encountered when proces- sing post-consumer PET bottle flake. The emphasis at KTDI is on manufacturing pellet / chip for high quality fibers, which require fine filtration. The Gneuss RSF genius Melt Filtration System of- fers this possibility without causing disturbances in the process and with long intervals between fil- ter element changes. The Gneuss line for recycling PET to fiber grade quality at KTDI attracted such interest that it was shown on Korean television. 格诺斯MRS挤出系统、旋转过滤系统RSFgenius 和在线粘度计VIS在KTDI实验室生产线中的应用 Gneuss MRS Extrusion System, Rotary Filtra- tion System RSFgenius and Online viscometer VIS in KTDI lab line