Vacuum handling systems from Schmalz rationalise and humanise production processes by permitting ergonomic and efficient handling of goods. The example of a Black Forest textile company demonstrates impressively how the widespread use of flexible vacuum tube lifter systems in the commissioning department makes work more economic and, at the same time, improves the motivation and performance of the employees.

The family-owned company STW Schwarzwälder Textil-Werke Heinrich Kautzmann GmbH in D-77773 Schenkenzell was founded in 1919 and today manufactures fibre fillers and chopped fibres. The firm currently employs 92 persons in production, logistics and administration and produces and sells various fibre products which are used in such areas as the building industry (in plaster, filling compounds, paints and reinforced concrete), the automotive industry (in friction pads, instrument panels, plastics and toothed belts) and in the paper industry. Depending on their texture and the quantities ordered, the fibre materials are delivered either in sacks or in cardboard boxes, as specified by the customers. The sacks generally weigh about 30 kg, while the weights of the cardboard boxes vary between 5 and 40 kg. From the very start, the responsible persons at STW paid attention to the health and motivation of their employees and purchased handling devices for the commissioning department - several vacuum tube lifters manufactured by the vacuum and handling specialist J. Schmalz GmbH in D-72293 Glatten with which the plastic sacks and cardboard boxes could be lifted and moved. For many years, the company was very satisfied with these vacuum tube lifters as aids to the material flow and this was why the new production hall was equipped with vacuum handling systems from Schmalz.

Complete material-flow solutions from the
modular range of standard components

However, the requirements in the new hall were greater than for the old systems. STW wished to provide a seamless connection between the production and commissioning areas with the aid of a crane equipped with two different vacuum tube lifters with different gripper system.

For this, the application engineers at Schmalz planned an aluminium crane system which extended over the entire hall, from the individual machines to the commissioning area. The two vacuum tube lifters can be moved from one end of the hall to the other, and from side to side, covering an area of 27 x 4.5 metres, which means that they can be used very flexibly on all machines.

The one handling system consists of a vacuum tube lifter JumboSprint with an integrated bow-type operator handle to permit precise gripping and safe movement of the heavy and unwieldy loads. This device is equipped with a vacuum gripper designed specifically for the handling of sacks. The second handling system comprises a vacuum tube lifter JumboErgo with a long movable bow handle matched to the application and a multiple gripper Compact for handling of cardboard boxes. As already mentioned, the sacks of fibre fillers can weigh up to 30 kg each, while the cardboard boxes may weigh up to 40 kg each. The process and handling sequences are very similar for both sacks and cardboard boxes. The raw materials are delivered as bulk goods and are then milled and the resulting chopped fibres are deposited in sacks held in metal frames. When the sacks have been filled and sealed, they are first placed on the floor, from where they are lifted with the vacuum tube lifter and placed in large shipping crates. For this purpose, the vacuum tube lifter has a longer tube cylinder so that it can reach to the bottom of the crates to permit easier positioning of the sacks.

Ergonomics and motivation for more
safety and productivity

In order to meet the varying requirements of their customers, STW also has a second production line which packs the fibres in cardboard boxes. Customers who purchase large quantities in sacks normally empty these upon receipt and all of the fibre material enters the production process. Customers who need only smaller quantities prefer the cardboard boxes, since they can remove the required amount of fibre and then seal the box and return it to storage. In this second production line, therefore, the milled fibres fall into cardboard boxes of various sizes which are then sealed with adhesive tape and placed on one side, ready for removal. The vacuum tube lifter with the multiple gripper Compact is used to lift the boxes, whose tops are often convex, and to place them on the waiting pallets. The vacuum tube lifter is equipped, as mentioned above, with a long and movable operator handle to permit stacking of the boxes to any desired height on the pallets. The multiple vacuum gripper Compact is designed to permit flexible and, above all, safe gripping of boxes of various sizes, some of which may be soft, made of various types of cardboard.

It should also be mentioned that the vacuum tube lifters are used in single-shift operation by unskilled female employees after a short training period. At each milling station, these employees move over 50 sacks or boxes with a total weight of about 1500 kg per day. The fact that they do this easily, safely and, above all, with no risk to their health is primarily due to combined material-flow and vacuum handling solution supplied by Schmalz. Special dust filters ensure reliable operation of the lifters by protecting the powerful vacuum blowers against the very fine fibre dust which results from the milling operations. Special silencer boxes, mounted under the roof of the hall to save space, reduce the noise generated by the blowers to a minimum.