Format adjustment in labellers with robust and cost-effective linear bearing technology

• What was needed: drylin linear bearing technology such as lead screw linear tables, plastic energy chains
• Requirements: Linear bearings with a hygienic design and resistance to aggressive cleaning agents were required for a wide variety of format adjustments. They had to be completely lubrication- and corrosion-free and at the same time offer favourable costs and a low weight.
• Industry: Labelling machines, packaging technology
• Success for the customer: The plastic bearings are completely lubrication-free, chemical-resistant, lightweight, dirt-resistant and corrosion-free. They are cost-effective and weight-optimised, while at the same time increasing the rigidity of the liner modules.

In this container transport module of a labelling machine from Krones AG, linear bearing systems, lead screw nuts and plain bearing bushings are used for various format adjustments. Specifically, these are used in this application in the parallel and height adjustment of the belt guide, the transverse and height adjustment of the sleeve brush and in the transverse and height adjustment for pre-shrinking. Here, the modules are adjusted in height and width to suit the various container sizes and formats, thus enabling a flexible labelling process.
Machines in the beverage industry in particular have high hygiene requirements. This means that all components have to be cleaned very aggressively and must also be completely free of lubrication and corrosion. The bearings must have a hygienic design and be open and flushable. They must always function perfectly, even in systems contaminated with drinks and glass. Finally, the container transport module should also be optimised in terms of cost and weight.

Today, drylin linear systems such as linear units with lead screw drives as well as plastic energy chains can be found in the various assemblies of the labelling machine from Krones. By using plastic bearings, completely lubrication-free, chemical-resistant, lightweight, dirt-resistant and corrosion-free solutions have been found from a single source. The components are also cost-effective and have a standardised design. By redesigning the components to bent sheet metal parts, it was possible to further reduce costs and weight while increasing their rigidity (milled steel parts could be omitted and replaced by laser-cut sheet metal parts). It was also possible to switch to a soft and favourable material for the shafts, as no hardened surfaces were required for the plain bearings. The freely available CAD data and the predictable service life of the bearings also proved to be advantageous for Krones during the design process.