| 摘要 |
Methods and apparatus for feeding continuous zipper material with sliders to a thermoforming packaging machine that advances the packaging film N package lengths each advance, where N is a positive integer greater than unity. In the packaging machine, pockets are thermoformed in a central zone of the web, while the zipper material is sealed to the web along a lateral zone that is parallel to the machine direction and does not intersect the pockets. A trailing portion of the zipper material in a zipper processing machine is advanced N times every work cycle, one package length per advance. A slider is inserted during each dwell time between advances of the trailing zipper portion. In the zone between the slider insertion device and the zipper sealing station, the zipper material is accumulated each time the zipper material is advanced without concurrent advancement of the packaging material. The accumulator retracts during advancement of the packaging film, allowing the accumulated zipper material to advance concurrently with the packaging film.
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