An article in Kunstoffe International industry magazine outlines the potential for recycling of PIN flame retardant plastics in the Circular Economy and presents results of recycling tests on glass fibre reinforced polyamide (PA6 and PA66) containing phosphorus flame retardants (mainly aluminium diethylphosphinate with phosphoric synergists). Such compounds are widely used for performance applications, e.g. in E&E (electrical and electronics) and automobile. Five recycling cycles were tested (granulation, drying, extrusion, accelerated ageing at 120°C, granulation). Results show that the repeated recycling reduces the length of the glass fibres, so impacting mechanical properties (E-modulus and tensile strength) whereas the presence of the PIN flame retardant had no negative impact on mechanical properties in multiple processing. Also, the fire performance of UL94 V-0 was maintained.
“Secondary raw materials of the future. Recycling halogen-free flame-retardant plastics. Example: polyamide”, C. Schultheis & E. Metzsch-Zilligen, Fraunhofer LBF, Kustoffe International 8/2018. Article online at https://www.flameretardants-online.com/news/?showid=18452 The testing presented is part of the PIN FR recycling project developed by pinfa (see pinfa Newsletters n°s 60 and 88).