Hygienic linear bearings for innovative vegetable packers without plastic

Profile

• What was needed: drylin SLW linear modules, with drylin plain bearing liner and flex shaft
• Requirements: For the numerous format adjustments, simple automated systems were needed that work without lubricants and, as far as possible, without maintenance.
• 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 slim design of the machine. The system meets all requirements and satisfies the decision-makers and machine operators.

In the video: the process for packaging fruits and vegetables in cardboard boxes. (german video)

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Problem

In the future, Reichenau-Gemüse, a producer organisation, will pack its tomatoes and apples in cardboard trays without any film and thus without any plastic. An S-shaped viewing slit allows a clear view of the product (see Fig. 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 of development was the wish of a corrugated board manufacturer to dispense with the usual flow packaging and the use of plastic film. The company launched a competition for ideas, which Michael Baur won. Challenge: bonding without counter pressure 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 special challenges here was to glue the printed packaging to the top after manually filling it with vine tomatoes: the gluing had to be durable. During the gluing process, however, counter pressure is not possible and, of course, pressure on the sensitive tomatoes must be avoided. An intelligent detailed design was the solution to this problem. The gluing points are applied with a hot glue station, but other processes such as sealing are also conceivable. A station for printing and applying labels has also been integrated into the system. When developing the prototype, Michael Baur attached great importance to flexibility and ease of use. This can be seen immediately from the numerous semi-automatic format adjustments (Fig. 2).

Solution

For the numerous format adjustments (see Fig. 3 below), Baur uses the lubrication-free drylin SLW linear modules (Fig. 4). They have a torsionally rigid aluminium double shaft profile combined with a trapezoidal thread. The carriage travels on drylin liners with incorporated lubrication - a solution widely used in food processing and packaging because no external lubrication is required therefore contamination is avoided. Baur uses SLW 1040 drylin linear units in different lengths with hand wheel, position indicator and lead screw clamping (Fig. 4). They enable the operating personnel to quickly reconfigure the packaging system for other package sizes and formats.
The complete system has a modular design and can operate either in an interlinked overall system or independently. The compact, slim design includes the synchronous drive in the folding and positioning units for both sides of the box. It is implemented with a flexible shaft, which is much easier than electronic coupling. All feeds move synchronously with the belt speed.
Both the decision-makers and the machine operators were completely satisfied with initial system operation in actual practice. It meets all the relevant requirements.
And the sustainable packaging does not have to be limited to fresh products. The system can also be used for packaging tools, incandescent lamps, and so on, in a plastic-free, environmentally friendly alternative to blister packaging.

Fig. 1: This packaging machine completely dispenses with plastic film.

Fig. 2: The compact machine packages fresh products such as vine tomatoes without film – gently and with a clear view of the goods.

Fig. 3: The wide range of options for format adjustment is an important prerequisite for flexible system use.

Fig. 4: Lubrication-free drylin SLW linear units are used for format adjustment on various axes.