Extrusion Asia Edition 1-2021

available in six sizes, from the MAS 24 laboratory extruder with an hourly output of 10 kg PE up to the high-performance ex- truder with an output of more than 2,000 kg/h. The range is supplemented by the CDF-melt-filters with very efficient, rotat- ing disc filters and the DRD-centrifugal-cleaners for the pre- treatment of input materials, especially for drying and the wa- terless separation of solids. Based on the co-rotating screws, the conical MAS-extruders of- fer a specific property profile that makes them ideal for com- plex recycling and compounding tasks. Outstanding is the very uniform plasticization at a comparatively low to medium pres- sure and shear level, documented by measurements of the phy- sical product characteristics. Their analysis show that the quali- ties of the input material stay at maximum after processing which is of decisive importance for both recycling applications and compounding tasks. Thanks to their modular structure, the screws can be easily and quickly fine-tuned to a specific task by exchanging individual screw-segments. Another advantage is the system-specific large feed opening on the extruder, which favors the feeding in of material with a low bulk density, such as recycling flakes or fibrous and powdery additives in compounding technology. MAS-ES compounder for multi-stage melt cleaning by means of degassing High up on the Pan Era Group's project specification was the ability to produce in an one-stage-process a particle-free HDPE in different colors, suitable for producing new high quality pa- ckaging films or various bottles for detergents or other house- hold chemicals. The area sales manager of MAS, Juergen Morosz comments: “The challenge was to correctly assess the input material in terms of its composition and degree of soiling and the system design required for processing. In close cooperation with the customer, after a series of representative material tests, we have found a process technology solution that optimally uses the potential of the MAS extruder. The ideal solution was, re- spectively is, a system concept derived from our ES compound- er extruder cascade. It consists of a single-screw extruder for melting and plasticizing the washed and dried PE flakes and a subsequent CDF 500-D twin disc filter unit from our supply pro- gram, where particles with a fineness of 130 μ m are retained and segregated. The thus cleaned material stream is then fed to the conical MAS twin-screw extruder by side-feeding in the area of the feed zone. But that was not enough cleaning. There were still printing ink residues and odor emissions in the melt. In order to remove these contaminations we have added a va- cuum unit to the specifically large intake opening of the twin- screw-extruder and converted it into a degassing zone, where the volatile melt components can be sucked off efficiently. From there the polymer melt is conveyed further, compressed gently and homogenized until it finally reaches a second degas- sing zone for second cleansing (Picture 5). Passing an MFI-mea- suring station, it finally reaches the granulating unit.” As an additional bonus, the system concept also offers the compounding ability which actually is used to achieve high de- gree of homogenization of the recycled resin. As it is the core property of the ES-compounder systems, there is the intention to use it for extending the scope of materials to compounded materials for technical applications. To do this, the feed zone of the MAS twin screw extruder only needs to be combined with a vacuum lock through which powdered additives such as talc or calcium carbonate can be added without the need for addi- tional side feeder units. This means that Pan Era Group has every opportunity to expand the r-HDPE range to include mate- rial variants for technical applications. 图4：Pan Era集团使用至少80％的r-HDPE制成的产品示例 （图片：Pan Era） Picture 4: Examples of product of Pan Era Group made from at least 80% r-HDPE (Photo: Pan Era) 图5：MAS的回收设备是由单螺杆挤出机（用于增塑预清洁的 PE薄片）（左）与双螺杆挤出机（用于有效排气）以及通过 与添加剂混合使回收产品更具升值潜力的成套设备 （图片：MAS） Picture 5: The MAS recycling plant is the combination of a single-screw extruder for plasticizing the pre-cleaned PE-flakes (left) and a twin-screw extruder for efficient degassing and the potential for up-cycling through compounding with additives (Photo: MAS) ➠ MAS Maschinen- und Anlagen Schulz GmbH A-4055 Pucking, Austria Juergen Morosz – MAS -Area Sales Manager E-j.morosz@mas-austria.com , www.mas-austria.com ➠ Author: Reinhard Bauer - TECHNOKOMM office@technokomm.at 20 回收利用 Extrusion Asia Edition 1/2021