The wheel reinvented How BALINIT CROMA PLUS literally keeps the business going …
Without the wheels, rollers and casters made by Blickle, much more than Europe’s postal logistics centers would be at a standstill. There are many other sectors in which the company, ranked third in the world market, keeps business running — including in Blickle’s own injection molding production. And there, the adoption of BALINIT CROMA PLUS has reduced the levels of both maintenance and waste.
A rhythmic booming echoes through the Blickle factory in Rosenfeld, Germany. A wheel is moving through the test process. Firmly secured, it rolls over thresholds on a disc that is turning beneath the specimen. With a load of up to 5 tonnes, the wheel must clear the obstacles successfully many times over to pass the quality test.
As a producer of 20 million wheels, rollers and casters per year, the company manufactures tailor-made products with special properties for a wide range of applications, be it shopping carts or pallet trucks, forklifts or conveyor belts. Over 8,000 items can be ready for shipping across Europe within one day and 12,000 more require only one or two days.
“In terms of vertical range of manufacture, we have the world’s largest center for wheel, roller and caster production right here in Rosenfeld,” says Marketing Manager Werner Herre. “Thanks to this bundled know-how and closely interlinked processes, we can turn standard goods into a special product relatively quickly, even in small quantities.”
A special product made of polyamide and TPU
A good example of the way these special products resolve challenges is the wheel innovation referred to as “POTHS”, on the market since 2019. The name stands for wheel bodies made of unbreakable polyamide and a running surface of thermoplastic polyurethane (TPU) for use in hygienic applications or the food production industry. Like its sister product “POTH”, it has a high load capacity (up to 550 kg) with low rolling resistance and, with its softer running surface, offers better noise damping and ride quality.
Good adhesion, but undesired side effect
During the production process, adhesive permanently bonds the wheel body and running surface. This requires the use of two injection molding machines. The first produces the wheel body, which is automatically transferred to the second machine, where a running surface is injected around the wheel body. “This way, the components adhere to each other better than if the running surface only clings to the wheel body,” explains Frank Binder, designer 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.”
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.
but not during production.
Blickle GmbH & Co. KG