| 摘要 |
The invention relates to a process and an apparatus for covering bar structures, such as frames, with heat-shrinkable film of plastic. Bar structures covered on both sides are subjected at opposite points to a stream of hot gas, the kinetic energy of which presses the film, which has been transformed into a viscous state, together in the region of the windows between the bars of the bar structure, so that an integral bond is obtained. This allows permanent sheathings of bar structures with plastic film to be produced. The invention envisages in particular the processing of frame-like bar structures in a continuous process, the latter taking along an endless film web which is drawn off two film supply rolls arranged on both sides of bar structures conveyed away. After this, they are subjected to the streams of hot gas on both sides and, following cooling, during further conveyance, the welded-together film webs can be cut between two bar structures in each case and the bar structures can then be further conveyed individually.
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