| 摘要 |
The mechanism is intended for welding layers of plastic foil as these are moved along in steps to form a continuous strip of plastic bags (with concertina side gussets). It comprises first and second clamps which are capable of gripping the foil layers and operate in conjunction with welding units. Third and fourth clamps, capable of gripping the foil layers, release the foil during the time that the welding units are operating. The clamps with the welding units are longitudinally movable to and fro relative to the clamps or vice versa. Used for mfr. of continuous strip of plastic foil bags with side gussets. The mechanism allows the foil to be transported without tensioning the foil until the welds are sufficiently cooled to absorb such tension. |
