| 摘要 |
Heat-sealable packaging films, particularly plastic bags, are hot pressure welded with an apparatus having at least one, and often two welding terminals, each having an electrically heated welding wire stretched thereacross. The welding terminal preferably has an elastic silicone backing which is protected from the welding wire by a covering material in the form of a sheath which surrounds the welding wire. The sheath is preferably made of plastic, such as polytetrafluoroethylene, which surrounds the welding wire with a minimum of play. When the sheath is formed from a sheet with overlapping edges, the area of overlap runs longitudinally with the wire and is arranged on the welding terminal such that it faces away from the packaging film being welded.
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