Extrusion International 5-2021

26 Extrusion International 5/2021 PROCESSING temperature to initiate the crystalli- zation process. In this way a degree of crystallization of 30% to 40% is achieved. In the crystallization chan- nel, the pellets are conveyed further by gentle vibration andmixed to pre- vent sticking during crystallization. Dominik Neumann (Team Leader R&D) mentions, “A high degree of crystallization is necessary to avoid agglomeration, which occurs with amorphous PET during the end use of the pellets (injection moulding). By using the ECON Crystallization System, a pre-drying of the pellets is no longer necessary. The system uses the intrinsic heat of the pellets for crystallization and is therefore one of the most ef fi cient methods of crystallizing PET.” In summary the ECON PET-Edition makes it possible to fi lter, pelletize and crystallize PET in just one-step, and using an underwater pelletiz- ing system instead of a conventional strand pelletizing system provides major advantages: - pelletizing, drying and crystallizing in only one production step - no vacuoles – high-quality pellets - high throughput – little space re- quirements - high process stability – consistent pellet quality - simple and safe start-up process After pelletizing, the PET recyclate is sent to a deep cleaning reactor. This process puri fi es the pellets so they can be reused for packaging in the food sector. At this point, the bottle- to-bottle loop comes to an end. Another important area in PET re- cycling is increasing the intrinsic vis- cosity (IV). For this purpose, various approaches are available on themar- ket: • SSP process: In the Solid State Polycondensation process (SSP), PETpelletsorPET fl akes are kept in a vacuum or inert gas for a few hours at temperatures of 200 °C to 240 °C. In this way, the molecu- lar chains are lengthened, and harm- ful components are removed. As the name suggests, the process is carried out in the solid state of PET. • LSP process: In the Liquid State Polycondensation process (LSP), the PET is condensed in the liquid state under vacuum to lengthen the molecular chains. This increases the IV value and removes harmful chemicals from the recyclate so that it can be used again in the food sector. The continuous process means that – in contrast to the SSP process – the desired IV can be kept constant and the process saves time and energy. Besides the equipment mentioned above, ECON offers air pelletizing systems, hybrid pelletizing systems and pyrolysis furnaces. Visitors to this year’s Fakuma have the opportunity to experience the unique ECON Pel- letizing Technology in a live demon- stration in Hall A6, Booth 6107. On display will be an EUP 10 Advanced, whichhas beendesigned tomeet the requirements of a 24/7 production. Due to the simple operation and the use of the ECON Thermal Insulation Technology this machine is ideal for small throughputs. Furthermore, the ECON Pyrolysis Furnace for Screws (EPOS) will be exhibited, which has been developed for an environmen- tally friendly cleaning of extruder screws. ECON GmbH – Fakuma Hall/Stand No. A6-6107, October 12 – 16 2021, Friedrichshafen, Germany www.econ.eu Dominik Neumann (Team Leader R&D) Gerhard Hemetsberger (Head of Sales) ECON Pyrolysis Furnace for Screws, EPOS Underwater Pelletizer EUP 10 Advanced