| 摘要 |
In this method, hot air at a particular temperature is blown onto lands (25, 26) for welding films (19, 21, 22, etc) two by two with transverse pressure (P) applied to the sheets to press them together, after which cold air is blown onto the welding lands. The machine welds a cellular block (18) of sheets (19, 21, 22) stacked by means of their mutual contact lands, the sheets delimiting horizontal cells (27, 28) between them. The machine comprises two batteries (23) of horizontal tubes (24) mobile horizontally and adapted to be introduced laterally into the horizontal cells of the block, the tubes being provided with nozzles (29) for blowing air onto the lands. This method heats the plates without contact and therefore dispenses with a cycle of cleaning the heat source. It easily welds cellular blocks of profiled polypropylene or polyethylene sheets without the drawbacks of other welding methods known in themselves.
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