Extrusion International 6-2019

61 Extrusion International 6/2019 Gneuss Kunststofftechnik GmbH gneuss.com nection and is thus not a field bus. IO- Link is manufacturer-independent and is becoming more and more widespread in industrial automation engineering. Most renowned con- troller manufacturers offer IO-Link masters, which are either directly fit- ted as an assembly in the controller or installed in the field and connect- ed via a bus system. The traditional melt pressure sensor with an analogue output knows sig- nificantly more than just the process pressure. The signal preparation on its inside has been digitised long ago, and as a result, it is in a position to provide valuable information that simplifies maintenance, increases safety and improves availability. Pre- ventive maintenance and condition monitoring can minimise downtimes and optimise process safety. The melt pressure sensor could make a sub- stantial contribution in this regard, if it could divulge its knowledge. But unfortunately, its communications facilities are limited to one direction and one measurement value. The Gneuss IO-Link sensor offers the possibility to access all those informa- tion. Its proven sensor technology, in combination with intelligent, digital communication not only offers moni- toring of the electronics tempera- ture, but also records the operating hours in different load ranges. Thus, the user can make out, during ongo- ing operation, when the electronics head is subject to high heat radia- tion due to its installation location, or the sensor is continuously working at the upper limit of its measurement range. In addition, Gneuss’ Measurement Technology division will present its complete line of pressure transduc- ers and transmitters, temperature sensors and accessories. Thanks to this design, the devola- tilizing performance is approx. 50 times greater than that of a conven- tional vented single screw extruder – and this at a vacuum of only 25 to 40 mbar. While other dryerless technologies are promoting at least partial pre-drying in the meantime, the MRS extruder can process R-PET with up to 1 % moisture content. By avoiding the need for a deep vacuum system and pre-drying, the MRS is an economically efficient alternative to conventional technologies. Further arguments in its favor besides en- ergy savings are the simple and rug- ged design, small footprint, its ease of operation and low maintenance, processing flexibility and last but not least its excellent melt quality and homogeneity. A Letter of Non Objec- tion (LNO) from the FDA, EFSA con- formity and several local approvals in Latin America confirm the decon- tamination efficiency of this technol- ogy. The days of analogue measurement value transmission in polymer tech- nology are numbered. With the re- quirements for flexibility, availability and safety of the machines and sys- tems becoming more and more strin- gent, there is a need for new, digital solutions. IO-Link is a worldwide standardised technology for digital linking of sen- sors and actuators. Communication takes place over a point-to-point con- interplastica 2020: 02 2B20 the reprocessing of highly contami- nated materials without pre-drying, especially bulky PET waste such as post-consumer bottle flakes and in- dustrial waste from fiber and film manufacture as well as polystyrene, nylon and other hydrophil polymers. A Gneuss Processing Unit consists of a Gneuss MRS extruder with its un- matched devolatilization and decon- tamination performance in combina- tion with a highly-efficient Gneuss Rotary Filtration System and an on- line viscometer VIS for intelligent dy- namic viscosity control. The MRS extruder itself has been improved considerably over the last decade and at the interplastica the second generation design will be on display. The enhanced drive de- sign is more robust to handle even more demanding recycling environ- ments. Thanks to several changes in the MRS drum and screw design the already unmatched IV retention has been further improved, while continuing to forgo pre-drying. The MRS extruder permits the process- ing of PET without pre-drying by us- ing a simple water ring vacuum sys- tem to process the material directly to high quality end products such as packaging sheet, strapping tape or filaments. This is achieved by means of its unique and patented process- ing section. Based on a conventional single screw extruder, the Multi Ro- tation Section is a drum containing eight satellite single screws, driven by a ring gear and pinion transmis- sion. The “barrels” cut into the drum are approximately 30 % open and pro- vide optimum ex- posure of the melt.