Filling line for yogurt: Hygienically designed with plastic plain bearings

Michael Rothdach GmbH in the Allgäu region is a renowned machine and plant manufacturer specialising in the processing, filling and packaging of food - with a focus on dairy products. The European market leader develops mixing systems for fruit yoghurt and bucket filling systems for foods such as yoghurt, mustard, ketchup and sauces under the brand name miromatic. The filling systems are customised on the basis of customer requirements, whereby the designers can draw on a modular system of individual standard stations. For example, there are functional units for the process steps of empty container provision, filling process (with weighing or inline flow measurement), lid provision and separation, lidding, sealing and labelling. All these modules vary and are therefore interlinked according to customer requirements.
The developers have to fulfil high availability requirements for all systems: 24/7 operation is the rule rather than the exception. Very high hygiene requirements also apply: Dairy products are particularly critical in this respect. This is why miromatic has developed various hygiene and sterile concepts, such as a line for the aseptic filling of dairy products under sterile air blanketing. All systems are designed to withstand at least daily cleaning with the usual methods (more or less aggressive cleaning agents, hot steam, high pressure). In addition, the exposed drive elements are lubricant-free to prevent contamination, and the components and materials used are FDA-approved.

Our plain bearings made from high-performance polymers fit this requirement profile. They are maintenance-free and wear-free and form a good friction pairing with aluminium and stainless steel. There are also polymer materials that have been developed specifically for food processing machinery and have the corresponding approvals. For these reasons, miromatic designers have been using a wide range of our plain bearings for more than ten years.
A few examples: On various guide and adjustment elements, bearings made of iglidur ensure precise guidance of rotary and linear movements (see Figure 1 below). Depending on the application, housing bearings, such as the drylin R linear guide here, are also used and simplify both production and assembly (Fig. 2). In ball screw drives, igubal spherical bearings compensate for misalignments (Figures 3 and 4). And the easy-to-operate format adjustment at the sealing stations is realised with iglidur J plain bearings (Fig. 5). Last but not least, our energy chains are also used to bring energy and signals to the moving axes of the mixing and filling systems (also Figure 5).
Which material from the iglidur program is used depends on the application. In addition to the 'all-rounder' iglidur J, the bearings must also fulfil special requirements, for example in terms of temperature, resistance to cleaning media or moisture absorption. Special iglidur polymers are available for this purpose.