Hygienic linear bearings for innovative vegetable packers without plastic

• What was needed: drylin® SLW linear modules, with drylin® plain bearing film and flex shaft
• Requirements: For the numerous format adjustments, simple automated systems were needed that work without lubricants and are as maintenance-free as possible.
• Industry: Packaging technology
• Success for the customer: The drylin® linear bearing solutions enable lubrication-free operation of the system. They contribute to the compact and lean design of the machine. The system fulfils all requirements to the satisfaction of the decision-makers and machine operators.

In future, the producer organisation Reichenau-Gemüse will pack its tomatoes and apples in cardboard trays without film and therefore without any plastic. An S-shaped viewing slit allows a clear view of the product (see image 1 below).
This innovation is made possible by the development work of Dipl.-Ing. Michael Baur. His company is active as a development service provider for special machine construction.
The starting point for the development was the wish of a corrugated cardboard manufacturer to dispense with the usual flow-wrapping and thus the use of plastic foil. The company launched a tender for an ideas competition, which Michael Baur won. The challenge: gluing without backing and without pressure on the product. In the next step, Michael Baur and his team built a prototype of the newly designed machine. One of the particular challenges here was to glue the printed packaging to the top after it had been manually filled with vine tomatoes: The bonding must be durable. During the gluing process, however, it is not possible to apply any pressure to the sensitive tomatoes. This task was solved by an intelligent detailed design. The glue dots are applied using a hot glue station, but other methods such as sealing are also conceivable. A station for printing and applying the labels is also integrated into the system. When developing the prototype, Michael Baur placed great emphasis on flexibility and ease of operation. This can be recognised at first glance by the numerous semi-automatic format adjustments (Fig. 2).

Baur uses the lubrication-free drylin® SLW linear modules(Fig. 4) for the numerous format adjustments(see Fig. 3 below). They combine a torsion-resistant aluminium double-shaft profile with a trapezoidal thread. The carriage travels on drylin® sliding films with integrated lubrication - a solution widely used in food processing and packaging, as no external lubrication is required and product contamination is therefore avoided. Baur uses linear units of the type drylin® SLW 1040 in various lengths with hand wheel, position indicator and spindle clamping(Fig. 4). They enable the operating personnel to quickly change over the packaging system to other pack sizes and formats.
The complete system has a modular design and can work in an interlinked overall system or independently. The compact and slim design also includes the synchronised drive of the folding and positioning units for both sides of the carton. It is realised with a flexible shaft: This is much simpler than an electronic coupling. All feeds move in synchronisation with the belt speed.
Both the decision-makers and the machine operators were completely satisfied with the first practical operation: The system fulfils all the relevant requirements.
And the use of the new sustainable packaging does not have to be limited to fresh products. The system can also be used for packaging tools, light bulbs etc. - as a plastic-free and environmentally friendly alternative to blister packaging.