Extrusion Asia Edition 2-2021

19 Extrusion Asia Edition 2/2021 ➠ Gneuß Kunststofftechnik GmbH www.gneuss.de PET waste for recycling, such as post-in- dustrial fibre waste and to other post- consumer sources of PET, such as ther- moformed pots, tubs and trays. The important difference in recycling these materials is that whereas with PET bottle flake, a certain IV drop extrusion is acceptable, the IV of fibre waste or ther- moformed pots, tubs and trays is at a level that any further IV drop would re- sult in unacceptable mechanical proper- ties. Typically, the only answer is to install a complicated and/or energy intensive li- quid phase or solid state IV boosting pro- cesses downstream of the extruder. The Gneuss MRS extruder for PET offers unparalleled decontamination perfor- mance (and has food contact approval for post-consumer waste without the need for any additional thermal treat- ment of the material). In addition to this, the new MRSjump version of this extrud- er provides a drastically increased surface exchange rate under vacuum so that par- tial polycondensation takes place within the extruder and it is possible to retain the input IV. n 目前，消费后的PET瓶片的回收已 经很成熟，并且已经成为第二次寻求回 收的机会。 越来越多的重点转移到使用其他 PET废料进行回收，例如工业后纤维废 料，以及使用其他PET的消费后废料， 例如热成型罐子，盆子和托盘。 回收这些材料的重要区别在于，对 于PET瓶片而言，一定的IV 降低是可以 接受的，而纤维废料或热成型的罐子， 盆子和托盘的IV的水平应使任何进一步 的IV降低都会导致不可接受的机械性 能。 通常，唯一的答案是在挤出机下游 安装复杂的和/或高能耗的液相或固态IV 增粘工艺。 适用于PET的Gneuss MRS挤出机 具有无与伦比的去污性能（并已获得食 品接触批准用于消费后的废物，而无需 对该材料进行任何额外的热处理。 除 此 之 外 ， 该 挤 出 机 的 新 型 MRSjump版本可在真空下显着提高表 面交换速率，从而在挤出机内发生部分 缩聚反应，并且可以保持输入的IV数 值。 另外，尽管输入材料的残留水分水 平不可避免地发生变化，但仍可以控制 聚合物在真空下强烈的脱挥发分和长时 间的停留时间，以提供一致的输出IV 值。 因此，新型Gneuss MRSjump既可 以对食品接触水平提供净化性能，又可 以在单个挤出加工步骤中保持和控制 PET的IV。 无需在挤出之前处理材料，并且除 了挤出之外，不需要其他的熔融或固相 IV增粘工艺。 结果：更低的能耗，更好的材料质 量，更大的灵活性，更小的机器占地面 积，更低的复杂性，更少的操作员关注 以及使用以前不经济回收的原材料类型 的可能性。 PET Recycling – Decontamination and IV Control in One Step n Currently, the recycling of post-con- sumer PET Bottle Flake is well established and it has become a sought after sec- ondary meantime. Increasingly, the focus is shifting toward using other sources of PET 回收 – 一步完成净化和IV值控制 Additionally, the intense devolatilisation and long residence time of the polymer under vacuum can be controlled to pro- vide a consistent output IV in spite of the inevitable variations in the residual mois- ture level of the input material. The new Gneuss MRSjump therefore of- fers both decontamination performance to food contact levels and the ability to maintain and control the IV of the PET in one single extrusion processing step. There is no need to treat the material prior to extrusion and no need for an ad- ditional melt or solid phase IV boosting process in addition to extrusion. The result: lower energy consumption, better material quality, greater flexibility, smaller machine footprint, lower com- plexity, less operator attention and the possibility of using types of raw material which were previously uneconomic to re- cycle.