Plain bearings for beverage filling machines

Heavy loads in breweries
Star wheels are under a heavy load in their day-to-day use in breweries. In large high-capacity breweries, up to 66,000 bottles pass along the lines per hour, which means there are 66,000 opening and closing processes per hour as well. To increase the service life of the rollers, numerous tests were carried out with a series of materials. “We had contacted different plastic suppliers at first,” remembers Jürgen Steimmer. “But the results were not satisfactory. Either the rollers wore even more quickly, or the rotating axis did. It was only when we decided to work with igus® that we gradually arrived at a solution to the problem. ” Bernhard Hofstetter, the technical sales consultant responsible at igus®, continues: “At that time, Krones knew us as a specialist for plastic bearings, but not for rollers. This application was a great chance for us to highlight other aspects of our portfolio. “

Tribological optimization
The two-component bearing was tested for almost a year before it was installed in the first Krones lines. Whereas the color orange was chosen first for the TPU outer sheath, this is now delivered in the company’s blue color. “We were able to kill two birds with one stone in this case,” Jürgen Steimmer explains. “Firstly, blue matches our machines better, and secondly, the blue dye has RoHS approval, which is why these rollers have now been being installed since summer 2009. .” The tribo-optimized plastic rollers are supplied in six different sizes. This is related to the size of the bottles and thus the clamps’ opening angle. The rollers are available for bottle diameters from 50 mm to 110 mm. “The opening angle for a 3 liter Cola bottle, for example, which is a standard size on the American market, has to be large enough for effective handling,” Steimmer explains. On account of their size and weight, these bottling lines can “only” handle 20,000 bottles an hour using the multi-purpose star wheel.

Special solution increases service lives

New two-component polymer bearing for star wheels in drinks bottling equipment
The demand for packed drinks is increasing. To ensure the fast and reliable handling of different sized glass and PET bottles, so-called star wheels play a major role in complex drinks bottling equipment. They are exposed to very large loads, particularly in the high-performance range. Their service lives have almost been doubled since they have been equipped with two-component plastic rollers.

Since being founded in 1951, Krones has evolved far beyond its original role as a mere producer of machinery and bottling lines. The company has become an “all-round partner” for its customers. creating harmonious, optimized synergies of mechanical engineering, line-related know-how, process technology, microbiology and information technology. Today, Krones is synonymous for “systems engineering”.

There are interesting e.g. for lines in large breweries or mineral water filling plates that have to handle many different bottle sizes. Since a star wheel compensates a diameter tolerance of 20 mm, one star wheel is not required for each individual bottle size. This means they do not have to be exchanged, thus saving filling plants set-up time and costs. “The wheels are in permanent use in the machines. Before, their service lives were limited,” says Jürgen Steimmer. “Which is why we had to urgently remedy the situation.” “