Vacuum cups are preferred components in the packaging industry for the gentle handling of goods. For economic reasons, short set-up intervals and fewer tool changes are required. The handling processes should run continuously and without interruptions that lead to expensive downtimes of the entire packaging line.

For this reason, all components for handling the goods must be reliable and as durable as possible. What's more, the mostly sensitive products, for example in the food industry, must be moved gently to avoid damage. High throughput also requires short cycle times.

In addition to the design of vacuum cups, the material determines the properties of the suction pads. Long service life and durability can be achieved with wear-resistant suction cup materials. Vacuum cups must be able to be positioned quickly but gently and evacuated quickly in order to achieve short cycle times. The wear-resistant composite material Varioflex meets the requirements of the packaging industry; its remarkable restoring force enables rapid mounting and removal in packaging systems with short cycle times. The suction cups achieve positioning accuracy in highly dynamic applications thanks to the dimensionally stable body. The soft, low-pressure sealing lip adapts flexibly to the product being handled and ensures minimal leakage even on uneven product surfaces.

The packaging industry and the food sector are increasingly confronted with individualized packaging sizes and packaging types. Different dimensions within a series or a batch require frequent format changes on the machines. Added to this is the wide variety of packaging. Innovative handling solutions must be able to cope with curved, uneven and flexible product surfaces. Bellows suction cups made of wear-resistant vinyl can grip sagging or curved goods with low leakage thanks to their flexible suction cup material. Vinyl is an excellent material with a long service life, even on abrasive product surfaces such as cardboard.

Robust rectangular suction cups made of FDA-compliant silicone are used for the gentle handling of film-wrapped goods that are difficult to move. Mounted side by side on a base plate, they can be used to create large vacuum grippers that can also handle product layers in film outer packaging with process reliability. With detectable suction cups, it is possible to recognize at an early stage whether suction cup components have entered the food to be packaged. The suction cup material used is a special mixture that can be detected by metal detectors and then separated out; this provides protection against contamination.

In addition to the handling task, the application and ambient conditions, the weight, dimensions and surface properties of the workpiece are decisive for the system design. Particular attention must be paid to the acceleration and forces acting under different load cases.

A distinction is made between flat suction cups, bellows suction cups and oval suction cups. Due to their geometry, flat suction cups are stable during suction and can be positioned accurately during placement. Additional support ribs in the suction cup increase lateral stability. Above all, they prevent flexible products from being sucked in and the suction cup from slipping during high acceleration.

Bellows suction cups are ideal for handling sensitive materials and for workpieces with uneven surfaces. Height and angle compensation is easy to implement. The workpiece is lifted by the lifting height of the vacuum cup as soon as the vacuum is switched on. Bellows suction cups are available in various designs with different numbers of folds. The more folds, the greater the lifting movements possible. However, lateral stability is then rather low, which is why bellows suction cups are suitable for purely vertical handling tasks. If a bellows suction cup is not suitable for stroke or height compensation, spring plungers are the right choice.

Oval suction cups are suitable for handling elongated or cylindrical workpieces such as strips, profiles, tubes or bolts. They also pick up curved workpieces and products with webs. In comparison, they have a higher suction force than round vacuum cups of the same width.

In addition to vacuum suction cups, there are also other load handling devices for packaging applications, such as area gripping systems and suction cup carpets. Bag pack grippers and area grippers handle individual workpieces or entire layers without changing grippers and regardless of the position of the workpiece. Bag pack grippers enable the reliable handling of dimensionally stable packs and shrink-wrap packaging. If the suction cell is completely covered, they can also pick up other packs. Area grippers prove their worth in repackaging systems for heavy cardboard packaging, for example. Suction carpets enable the suction of variable product geometries. pb