Look and feel are the two senses which determine the high quality of furniture components made of expensive wood. Before the components are assembled, however, they have to be handled and worked by many different craftsmen. This also applies to a company known only to a few insiders -- Lufthansa Technik AG in Hamburg – which, amongst other things, is responsible for the exclusive to luxurious internal fittings in aircraft. Although this sounds more like a traditional craft, it is in fact a mixture of craftsmanship and high technology, since the internal fittings of an aircraft must comply with weight limits and stringent safety requirements in spite of all their luxury features. For this reason, light and fire-resistant sandwich elements with top-quality veneers are being used more and more. In additional to craftsmanship, the working of these elements demands great care in the handling of the parts in order to avoid damage to the veneered surfaces. Joiners and furniture builders receive effective support in this respect from the vacuum specialist J. Schmalz GmbH in 72293 Glatten, in the form of vacuum workbenches of the type PVT and paint-drying trolleys of the LWZ series.

Careful and secure clamping of
veneered furniture parts

More than 30 vacuum workbenches are used in the Lufthansa workshops to carefully grip and hold the sheets and other parts for working of their top surface and all edges. Clamping with vacuum has the great advantage that this method does not compress the surface or damage the cellular structure of the sandwich elements. Clamping with large suction pads leaves the top surface and all four edges of the part accessible for work such as grinding, drilling, application of edges, mounting of hinges and other fittings and final finishing. The vacuum workbenches of the type PVT-2 used here each have two suction plates with the dimensions 100 x 300 mm, sensing valves for activation of the vacuum and a height-adjustment feature. The main beam can be turned through 180° and engaged at angles in steps of 45°, permitting the worker to find an ideal working position. Each vacuum workbench has its own ejector to generate the vacuum and a foot-operated valve for gripping and releasing the workpiece. The vacuum workbenches PVT from Schmalz hold the workpieces securely under all conditions: with a vacuum of  60%, the holding force is about 90 kg. The suction plates can be moved and tilted to adapt them to the shape and size of the workpiece and thus to ensure secure gripping.

Storage and transport

In order to transport the (partially) finished workpieces carefully from one work position to the next, Lufthansa Technik AG uses so-called paint-drying trolleys from Schmalz. These can be loaded and unloaded from both sides, can carry loads of up to 300 kg and have adjustable supports in the form of telescopic rods. These rods can be inserted in any of the many holes in the frame, permitting varying shelf heights, and are held securely in order to provide a flat support for the workpieces. The trolleys are very stable in use. The Lufthansa workshops use these flexible trolleys for storing and transporting the sheets and components, and they thus form the connecting link in the flow of materials in the course of production.

The people at Lufthansa Technik AG were so pleased with the vacuum workbenches and paint drying trolleys that they have gradually phased out all of their conventional benches and transport trolleys. Furthermore, the Lufthansa engineers took advantage of the vacuum expertise from Schmalz to build their own "sanding bench", which is naturally constructed from vacuum components supplied by J. Schmalz GmbH. The special feature of this sanding bench is that the resulting dust, which can cause health problems, is removed by an extractor system mounted directly above the bench and collected in a filter system. This bench also allows sanding of the top surface and all four edges without repositioning the workpiece.