For almost 45 years, Hans Zipperle Antriebstechnik, based in Renningen, Germany, has specialized in the manufacture of plastic drive components, producing these parts exclusively by means of injection molding. The process enables Zipperle to produce tight-tolerance, precisely engineered products, which, in some cases, are finished using conventional machining processes. Next to the products created according to customer specification, the company delivers a standard range of thermoplastic drive components, including cylindrical gears, bevel gears, gear racks, sprocket wheels, small bevel-gear systems, and planetary gears, typically made from polyamide (PA) and polyacetal (POM) materials.
Now, however, the company has added to its product range a series of highly wear-resistant gears for the machinery, equipment, and precision mechanics industries, comprised of standard and custom parts made with extremely high accuracy in various geometries. For these products, a material was required with enhanced wear-resistance properties. Ultimately, the choice fell on Akrotech PK, an aliphatic polyketone compound produced by German compounder Akro-Plastic GmbH, based in Niederzissen in the Rhineland-Palatinate region of Germany. Characterized by outstanding mechanical properties, aliphatic polyketone compounds exhibit excellent wear breakage, chemical resistance, toughness on impact loading, and extremely high abrasion resistance.
"The particularly favorable mechanical properties make this new material extremely interesting for our products," said Hans Zipperle, Managing Director of Zipperle Antriebstechnik. "Its exceptionally high abrasion resistance and very good tribological properties make gears manufactured with polyketone suitable for significantly higher power transmissions than the gear materials typically used."
The company has now added cylindrical gears and bevel gears made of polyketone to its product line-up. These have already undergone extensive testing by Hans Zipperle Antriebstechnik on in-house developed test rigs, which included wear testing conducted on similar gear pairs using a bevel-gear system. These tests clearly showed the benefits of using Akrotek PK: The service life of bevel gears made from this material was found to be significantly longer than that of those made from the more traditional materials, PA and POM. Inspection of the POM and PA bevel gears on completing the test revealed extreme signs of wear, while the bevel gears made from polyketone were found to be virtually wear-free. Using the aliphatic polyketone compound, therefore, could extend the useful life of the gearboxes, in addition to decreasing downtime for repair and maintenance work. Moreover, the mechanical properties of the material have made it possible to expand the list of potential applications for various gears.
Hans Zipperle summed it up neatly: "Polyketone has become our go-to material for use in the gear sector and provides a superb alternative in our material profile."