Abstract: When packing articles, particularly sheet stacks, such as computer lists, for transportation and dispatch purposes in a film, thick stacks should be tightly enveloped with a shrink film envelope, so as to increase their transportation stability, whereas the envelope of thin stacks is to remain unshrunk, so as not to deform the stack. It is proposed that both types of articles be passed in the packing line through the shrinkage tunnel, but in the case of articles not to be shrunk by increasing the passage speed and/or decreasing the circulating air speed, the heat transfer conditions are reduced in such a way that no shrinkage occurs. It is also proposed to so control the welding dies or jaws of a longitudinal welding station as a function of the thickness of the articles that thinner packs are more tightly enveloped than thicker packs.

Abstract: The welding frame (3) of a film-welding device (2) is at the start of its pivoting movement motor-driven in positive manner over a few radians and is then released from the drive, so that only on the basis of its flywheel energy and weight force is it moved on to the locked closed position. Thus, accident risks can be avoided without separate control means, because for stopping the welding frame (5) it is essentially only necessary to dissipate the relatively low flywheel energy.

Abstract: In an apparatus for treating plate-shaped articles in a liquid medium including a bath containing the liquid medium with gap-like inlet and outlet openings arranged beneath the liquid level and a conveying device for conveying the plate-shaped articles along a substantially flat path of conveyance through the inlet and outlet openings and through the liquid medium in the bath, in order to reduce the loss of liquid from the bath, it is proposed that the inlet and outlet openings comprise sealing elements which are movable from a closed to an open position as the plate-shaped articles pass through them and which are furthermore of such design that the gap created by the sealing elements in their open position is substantially adaptable in height and width to the cross-section of the articles passing through it.

Abstract: A shrinkage tunnel (11) for heat treatment of shrinkable films has a hot air unit, which can be inserted as a standard unit in a tunnel wall and contains a radial fan (22), which is surrounded by a fan casing (26) formed from two sheet metal half-shells (27, 28). Between them they form a ring nozzle (30) with an axial outflow direction with respect to fan shaft (25), while air return flow opening (32) is centrally and directly positioned below the fan wheel (22). The heating system is integrated into the fan casing, so that the complete hot air unit (20) is an independently functional and preassemblable component.