1 year ago

MDA Technologies 2/2016

MDA Technologies 2/2016

Lubricant-free plastic

Lubricant-free plastic ball bearings ensure smooth running of labeling machines MACHINE ELEMENTS In the beverage industry, bottling and labeling always goes hand in hand. Krones AG, based in Germany is an expert manufacturer of packaging and bottling machines for the beverage industry. For its labeling machinery, Krones AG relies on lubrication-free and maintenance-free plastic ball bearings from igus GmbH. 03 Xiros ball bearings from igus are used in the guide rollers of the film storage One step in the overall process during bottling and filling is the labelling of bottles. Krones uses various methods including the stretch and shrink system unique to the “Sleevematic” technology, where pieces of label are unwound from rolls, cut and then attached to the bottles. For the filling process to run as fast as possible, an uninterrupted flow is required here. If a roll of labels is depleted, it About Krones AG Krones AG was founded in 1951 and is headquartered in Neutraubling near Regensburg in Bavaria, Germany. The company manufactures and sells machinery, plants and systems primarily for the beverages and food industry. Besides the main office, the headquarters in Neutraubling houses the construction, distribution and assembly of machines and plants for product filling and other features. Approximately 6,000 employees work at the site Neutraubling, and about 12,200 people work for the company worldwide. Nearly 90 percent of plants that Krones manufactures individually for customers are exported abroad from Germany. MDA Technologies 2/2016

needs to be replaced by a new one without stopping the entire plant. Here the so-called “buffer conveyor” is used as a film storage, in which Krones employs lubrication- and maintenance-free ‘xiros’ plastic ball bearings from igus. The film storage serves to prepare for a roll change: depending on the size of the system up to 36 guide rollers made of aluminium are used here to guide the webs of labels. One half of guide rollers is arranged offset next to each other in a row, which can move up and down on a rail. The other half is firmly installed above. During operation, the rows of rollers move apart vertically, the band of labels is routed one after the other through the system by a lower and an upper guide roller respectively, thereby creating a “buffer” for the ongoing operation. Once a roll with labels is depleted, the moving row with guide rollers moves back to the stationary one, whereby the buffer becomes smaller. Thus the user will have enough time to switch to a new label roll. The plant is somewhat slowed down by it, but this technology ensures an uninterrupted operation. 01 In the film storage, the Sleevematic from Krones prepares the switching to a new label roll Distinct advantage: Smooth running Sören Meissner, designer at the department of inspection and labelling technology at Krones explains “Imperative for us here is the smooth running of the ball bearings in the guide rollers. In the past we have used metallic bearings. However, this was not smooth enough; sometimes making the complete roll stop and the label band would slip over it.” As compared to the metallic bearings used before by Krones, the ‘xiros’ ball bearings from igus have lower mass and therefore ensure smooth running in the guide rollers. Here glass beads are used as rolling elements, which are held by plastic ball races in the bearings. Inner and outer rings of the ball bearings consist of xirodur high-performance plastics, which are distinguished by excellent friction and wear values. “Another advantage is the lubricant-free property of the ball bearings thus eliminating the need for maintenance,” says Meissner. 02 Depending on the size of the system, between 12 and 36 guide rolls are used in the Sleevematic of the film storage. Two xiros ball bearings from igus are used per guide roller Developing a new system solution For the labelling machine “Sleevematic”, igus currently supplies the xiros ball bearings, but the next step is already being planned: “We will soon be using our new system solution as guide rollers” explains Bernhard Hofstetter, field staff at igus. “This system solution consists of a light, clear anodised aluminium tube and two flanged ball bearings.” For these guide rollers, igus also offers on its website a configurator, with which the user can configure their components easily with a few clicks and order online. This complete solution saves considerable installation time, because igus preassembles the guide rollers. “This solution would of course be easier to use, because no holding fixture needs to be manufactured separately and everything is supplied from a single source,” says Hofstetter. This is very interesting for a series application such as the film storage of the Sleevematic from Krones. Virtually the entire range of products in use In the Krones bottling plants almost all products from the range of lubricant-free bearing from igus are used: from drylin linear bearings and iglidur plain bearings up to plastic threaded drive nuts and xiros ball bearings. The freedom from lubricant is a crucial factor, particularly in the food and beverage industry. “Here, a contamination of food with fats or oils must be avoided in all cases,” says Bernhard Hofstetter. “Another plus point is that moisture or chemicals cannot damage our plastic products and thus the cleaning process of machinery and equipment require no special attention.” Photographs: lead photo and 01 Krones AG, 02-04 igus GmbH 04 Sören Meissner (right, Krones AG) and Bernhard Hofstetter (left, igus GmbH) are already planning new projects using lubrication- and maintenance-free plastics About Igus GmbH igus GmbH is a globally leading manufacturer of energy chain systems and polymer plain bearings. The Colognebased family business has offices in 36 countries and employs around 2,700 people around the world. In 2014, igus generated a turnover of 469 million euros with motion plastics, plastic components for moving applications. igus operates the largest test laboratories and factories in its sector to offer customers quick turnaround times on innovative products and solutions tailored to their needs. MDA Technologies 2/2016


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