BEYOND SURFACES

of injection molding tools. An additive in the TPU ensures particularly good adhesion between the rim and tire. Adhesive residues in the machine and hot runner This adhesion is also the source of an undesirable side effect: The synthetic material adheres stubbornly to the injection molds as well. Demolding is made more difficult, and the material residues in the mold are nearly impossible to remove. After only a few hundred shots, the mold must be cleaned — a removal and reinstallation procedure that lasts 2.5 to 3 hours. The machine and the hot runner must also be cleared of TPU with every more lengthy shutdown, says Binder: “The melted material only has a pot life of around 15 minutes, then it decomposes.” BAlInIT ® CRomA plUS against sticking Blickle was looking for a suitable tool coating to get the sticking under control and to reduce the considerable amount of work as well as the volume of residue — and found it in BALINIT CROMA PLUS. The CrN-based, extremely hard multilayer coating protects tools from abrasion and scratches and reduces adhesion of the plastic melt due to its ceramic-like properties. The formation of residues was greatly reduced and deposits could usually be removed manually using simple means without dismantling the tool. The result: significantly longer maintenance intervals and less scrap. The positive outcome didn’t even require much time: “Inquiry, tests and implementation — it all took just a few months,” says Ronald Baumhöfer, Key Account Manager, Plastic at Oerlikon Balzers. Blickle gmbh & Co. Kg › Founded in 1953 › Over 1,000 employees Leading manufacturer of wheels, rollers and casters with more than 17 sales companies in Europe, America and Asia as well as representatives in 120 countries. www.blickle.de Solutions Sticks the way it should — but not during production. Beyond SURFACeS 02|2020 35