Smart Molding International 3-2021

materials 47 www.smart-molding.com I n addition to the automotive indus - try, the electrical and electronics (E&E) industry is the most impor - tant field of application for the LANXESS thermoplastic compounds Durethan (polyamide 6 and 66) and Pocan (poly - butylene terephthalate). The specialty chemicals company is expecting a sharp rise in demand for the flame-retardant variants of these plastics due to factors such as increasing electric mobility and digitalization in all areas of life. Proces - sors of these plastics are being support - ed with an extensive range of technical services such as demolding and flow property analyses. LANXESS has recent - ly expanded its service offering in this area. An experimental injection mold for an application-focused part was developed in the company’s own tech - nical lab for polymer processing at the Dormagen plant. The mold reflects the typical challenges encountered during injection-molding of flame-retardant polyamide and polyester compounds. “We want to use this mold for the realistic analysis of new flame-retar - dant as well as hydrolysis-stabilized materials. First, our aim is to identify their special processing characteristics ahead of time so that we can adapt the formulations, where required, al - ready during the product development stage,” explains Katharina Schütz, a project engineer at the polymer pro - cessing lab of the High Performance Materials (HPM) business unit. “Sec - ond, we want to give processors of our flame-retardant plastics specific processing recommendations for se - rial production.” Reproducing and addressing customer challenges in a practice-based manner Most flame-retardant thermoplastics have a narrower processing window than standard products due to the ad - ditives that are used. If the process pa - rameters are not chosen ideally, this can result in deposits on themold or surface defects on the component. Non-ideal processing can also often impair theme - chanical properties of the compounds. Schütz: “This experimental mold allows us to reproduce these challenges in a practice-based manner and find ways for improvement.” The injection mold developed by the HPM plastics experts is a highly func - tional, housing-like demonstrator part integrating numerous aspects from dif - ferent areas of application. Its complex geometry exhibits sudden changes in wall thickness, openings, larger planar sections, ribs and rough “imitations” of plug connections. Snap fits with differ - ent geometries – similar to those on e.g. terminal blocks – have also been integrated along with screw bosses of varying diameters. Material analysis tests on the component “The palm-sized part can also be used for mechanical, electrical and flame- retardant testing to evaluate the per - formance of a material depending on various process parameters and practi - cal geometry,” explains Sarah Luers, an expert in E&E application development at HPM. The tests that HPM performs among others at its part testing center include drop tests, tracking resistance measurements in accordance with UL 746A or glow-wire tests in accordance with IEC 60695-2-11 to -13. Analysis of stress cracks in overmolded metal parts HPM is constantly expanding its pro - cessing toolbox so that it can continue to provide effective support for its cus - tomers in the E&E industry. An experi - mental mold for plastic-metal hybrid parts will also be brought into opera - tion in the future. “Plastic components featuring overmoldedmetal inserts can be susceptible to stress cracks when they are exposed to large temperature fluctuations. We want to use the new hybrid mold to investigate and improve the crack resistance of materials that we are specially developing for these appli - cations,” says Luers. The business unit is also planning to use the mold to vali - date a simulation model for predicting stress cracks depending on factors such as the material, component geometry and processing parameters. LANXESS www.lanxess.com LANXESS expands customer service for the electrical and electronics industry The specialty chemicals company is expecting a sharp rise in demand for the flame-retardant variants of these plastics due to increasing electric mobility and digitalization in all areas of life. Picture: LANXESS