| 摘要 |
The present invention is directed to an end stop (134) for a thermoplastic b ag (120) having a reclosable fastener (121) at the open top end of the bag. The reclosable fastener (121) comprises a pair of interlocking fastening strips (130, 131). The end stop (134) is configured to facilitate snap fit insertio n onto the fastener strips (130, 131) and includes a top portion and a pair of depending side portions (172, 174) that straddle the fastener (121). The sid e portions (172, 174) further include inwardly directed tab and shoulder structure (198, 202) that engage the reclosable fastener and prevent the end stop from being inadvertently pulled off in a transverse direction in order to hold the end stop in place prior to being bonded to the bag. The bonding ste p is preferably accomplished by ultrasonic welding. In the case of the line production of thermoplastic bags wherein a continuous web of plastic materia l is moved from one station to the next, the invention allows for the positioning of the end stop onto the reclosable fastener at a first station and the bonding of the end stop to the bag at a second station. The positioning and bonding steps may be performed simultaneously.
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