Smart Molding International 2-2023

34 smart_molding international 2/2023 molding technology three ENGEL easix articulated robots for preparing large quantities of metal inserts and for handling the thermoplastic sheet, an ENGEL viper 90 linear robot and an ENGEL IR oven. The double-shell structure made it possible to integrate the air ducts directly into the carrier structure. The two half-shells are produced in a one-shot process. To do this, the two thermoplastic sheets are simultaneously heated in the IR oven, and then inserted into the mould, where they are formed and functionalised. Innovative recycling for fibre composite parts Recycling fibre-reinforced composite parts is another development focus at the ENGEL Technology Centre for Lightweight Composites. "In the future, we expect automotive recycling to play a role in returning many fibre- reinforced parts made of polyamide and polypropylene to the material cycles in a single grade process. However, the glass fibres are shortened when the parts are shredded. To again produce high-quality fibre composite parts from the returned materials, new fibre material does need to be admixed during processing of the recycled materials," as Fischer explained. "We are working on a solution here that lets us tune the material properties in a very efficient way." The basis is the new Two-stage process which ENGEL presented at the K show 2022. To be able to integrate a melt filter and a degassing unit, the production cell brakes down plasticising and injection into two independent, but mutually tuned, process steps. Thanks to this strategy, plastic waste can be processed as flakes in injection moulding directly after grinding to achieve excellent quality. Since a complete processing step, repelletising, is eliminated, the Two-stage process saves a huge amount of energy and work compared to legacy recycling. In order to be able to reprocess shredded fibre-reinforced plastic composite parts to create vehicle parts capable of withstanding high mechanical loads, ENGEL is now integrating a glass fibre feed into the production cell solution in addition to the melt filter. The fresh long glass fibres are admixed before injecting the melt. "We are in the trial phase here," said Fischer. "Initial trials are very promising." Fuel cells drive innovation Alternative drive technologies are also opening up new potential for the injection moulding industry. "Hydrogen technology is currently being promoted particularly strongly in Europe, especially in the truck sector," as Fischer reported. "The Cellcentric joint venture sees Daimler Truck and the Volvo Group bundle their experience in the development and production of fuel cell systems, and they have chosen ENGEL as one of their technology suppliers." New mobility applications sometimes require particularly large injection moulding machines. ENGEL builds mega machines with clamping forces of more than 10,000 tonnes