Extrusion International 6-2022

54 Extrusion International 6/2022 UNDERWATER PELLETIZING SYSTEM Better Performance and Optimized Workflows for TPE Production Key factors in upgrading the Maag underwater strand pelletizing system at HEXPOL TPE's site in Germany were the possibility of incorporating higher amounts of recycled content and making workflows much simpler. The resulting improvements will boost the corporate sustainability strategy and improve potential in production. "It's a must-have," comments process engineering manager Dominik Fehn. H EXPOL TPE GmbH, based in Lichtenfels, Germany, specializes in the production of thermoplastic polymers (TPEs): rubber, thermoplas- tics, and elastomers. Certified to ISO 9001, ISO 14001 and ISO 50001, the company's product portfolio includes thermoplastic elastomers as well as soft PVCs, TPE compounds with TPS, TPO, TPV and TPU, additives, and mas- terbatches. Looking to the future, HEXPOL TPE GmbH managing director Jochen Schneider says: "More recycledmaterial and bio-based compounds will play an increasingly important role for us." He and his colleagues are also keen to see a general improvement in performance in the plastics industry. So managing director Schneider, process engineer- ing manager Dominik Fehn and opera- tions manager Markus Schirrmacher set out to find solutions to optimize the productivity of their existing lines. They focused on the challenge of producing high-performance, high-quality com- pounds meeting the specific needs of customers in demanding sectors. An innovative pelletizing system to meet all requirements HEXPOL TPE's search for high-per- formance solutions to meet its re- quirements didn't take long. It has had close links with Maag for a number of years. The vendor of pelletizing sys- tems for polymer and compound pro- duction is a long-established supplier to the polymer manufacturer. Maag pelletizers have been running suc- cessfully on several lines at the plant in Lichtenfels for some time. So the cooperation between the two part- ners is built on deep-rooted trust and experience. HEXPOL TPE uses Maag dry-cut strand pelletizing systems for numerous pellets in its compounding operations, as well as its traditional- design underwater pelletizers. And the long-standing customer is always interested in new develop- ments that will improve performance, make production more flexible, and so equip it to meet the growing de- mands of the market. So when Maag launched PEARLO, HEXPOL TPE and its engineering expert were keen to find out more. The underwater pel - letizing system is designed to process a wide range of polymers and ther- moplastics, promising profitable pro - duction with throughputs of up to 42,000 kilograms per hour. Underwater pelletizing with PEARLO The key element of the PEARLO sys- tem is the cutting chamber. The knife configuration is basedon a turbine; the water inflow and outflow are tangen - tial. This means the product is advanc- ing as it rotates. This cutting chamber geometry developed by Maag enables extruded plastics to be cooled and cut so that much higher outputs are pos- sible with the same water quantities and the same input and output dimen- sions. The smart knife configuration also means that more knives operate simultaneously. The cut rate is also higher, so increasing throughput. The specific output limit has been greatly increased as a result. "We had initial discussions about the new system at the K-Show back in 2016 when PEARLO was first launched, after which trials were run at Maag's technical center in Xanten," recalls process engineering man- ager Dominik Fehn. His colleagues were also quickly convinced of the machine's capabilities, as operations manager Markus Schirrmacher con- firms: "We saw the benefits of the system right away, so we decided to buy a PEARLO in 2017." The system's performance in prac- tice proved them correct: "We've HEXPOL TPE GmbH based in Lichtenfels, Germany, specializes in the production of thermoplastic polymers (TPEs) (All pictures, source: HEXPOL TPE GmbH)