Lubrication-free without contamination: Bearing technology for labelling machines
Dry-operating high-performance polymers in format adjustment of Krones labelling systems
Up to 50,000 containers per hour can be labelled with just one unit – this number alone says enough about the newly developed Sleevematic TS from Krones AG. The company has succeeded in doubling the performance of the system compared to the predecessor series. One major reason for this is that instead of the classic cutting of the sleeves they are now micro-perforated. A large number of lubrication-free plain bearing components, which have proven their worth at Krones for many years, are also used.Profile
- What was needed: iglidur J flanged lead screw nuts, drylin R linear bearings, drylin W profile guides, drylin SLW lead screw modules, drylin N low-profile linear guide, xiros polymer ball bearings
- Requirements: For the bearing points, completely finished system solutions were needed that work without lubrication and maintenance.
- Industry: Beverages sector, labelling technology
- Success for the customer: Our bearing technology is used in a lot of places ranging from the belt station and the sleeve brush and the inlet and outlet sensor up to the manual adjustment in the pre-shrink and the height adjustment of the deflection rollers. It operates completely lubrication-free and maintenance-free and reduces downtimes to a minimum.
Problem
Krones AG manufactures and sells machinery, plants and systems primarily for the beverage and liquid food industry and considers itself to be a systems provider rather than a pure machine supplier. The turn-key systems cover all processes, from beverage production, packaging and labelling through to inspections and palletisation. There are various methods for labelling; one of those used by Krones is the stretch or shrink technology of the Sleevematic series.Here, Krones now offers an advanced technology with the Sleevematic TS. The TS stands for Top Speed, because with it, it is possible to label up to 50,000 containers per hour with just one unit. Before the individual sleeves are applied to (shot onto) the bottles, cans or other containers, they are no longer cut individually from the roll, but the sleeve is now micro-perforated. It is thus possible to allow continuous movement of the sleeves. Instead of cutting blades, the Sleevematic TS uses two rotating perforation cutters. In addition to the increased output, a further advantage is the significantly longer service life of the cutters. While the four cutting blades required in the past can be used for approximately five million cuts, the present two perforation knives are designed for up to 70 million cuts.
Rotary and linear bearing solutions are used at the various stations of the labeller.
Since highest safety standards for the protection of consumers are applicable to beverage and food technology, it is important for designers to be able to rely on products that do not require external lubrication, thus eliminating the possibility of contamination of the food or beverage.
Based on the modular concept of Krones, the Sleevematic TS also made use of existing components. The company continues to rely on our lubrication-free plastic solutions for various adjustable parts and other movable components.
Solution
Transverse and height adjustment of belt station (Picture 1 below):The transverse adjustment of the belt station is ensured by an iglidur J trapezoidal thread flange nut, which is insensitive to dirt and lubrication-free. For the height adjustment, iglidur J flange nuts and FJUMT adapters are used for easy installation in combination with the sheet metal bending parts.
Height adjustment of the sleeve brush (Picture 2):
The height adjustment of the sleeve brush is ensured by a trapezoidal lead screw nut in combination with drylin R solid plastic plain bearings. This made it possible to work very compactly and cost-effectively.
Transverse and height adjustment of pre-shrink unit (pictures 3 and 4):
The height adjustment of the pre-shrink unit was implemented with a drylin SLW-1040 lead screw module including clamping, position indicator and crank for format adjustment. The compact design allows for easy integration. The transverse adjustment can also be precisely adjusted in width with a hand crank.
Height adjustment of the down-holder (picture 5):
A lead screw module of the type SLW-2080 is used in the height adjustment of the down-holder. It enables a simple and user-friendly operation of the machine. In addition, plastic energy chains undertake the guidance of the cables.
Adjustment of inlet and outlet sensor (pictures 6 and 7):
Both the inlet and outlet sensors are adjusted with a WS-1040 profile rail and a carriage including a manual clamp. By the individual weighing, the adjustment could be made very compact and flexible.
Height adjustment of guide roller (picture 8):
A drylin SLW-1040 lead screw module including angle drive and accessories is used for the height adjustment of the guide pulley. It was possible to make the compact adjustment unit more user-friendly by deploying the angular drive. The adjustable roller determines the position of the additional perforation on the label.
Film accumulator with guide rollers (picture 8):
Previously used metal bearings in the guide rollers did not run easily enough and the complete roller partially stopped. Today, they each consist of two smooth-running xiros polymer ball bearings and an anodised aluminium tube. Depending on the size of the system, up to 36 guide rollers are used. The xirodur high-performance plastic in the ball bearings also enables very good coefficients of friction and wear.
Adjustment of the safety door (picture 9):
Finally, the adjustment of the safety door is ensured via the drylin N-27 series. The extremely flat guidance could be accommodated in a narrow space and secured with the Plexiglas protection door in front of the access into the perforation.
Josef Mayer, Head of Product Management Inspection and Labelling Technology at Krones AG
25 years of partnership.
Krones and igus now have more than 25 years of partnership. "The collaboration is great," concludes Josef Mayer. "The support right here on site works very well. You look sometimes in the catalogue somewhere else and thinks that the concerned product might roughly fit. At igus, however, you have a personal contact and always receive straightforward and suitable solutions immediately, even during prototyping." However, igus is also benefiting from the cooperation - new ideas and initiatives of the customers are also creating new products, whereby the flow of innovation always remains in motion.
