| 摘要 |
The present invention is directed to an end stop (134) for a thermoplastic bag (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 insertion 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 side 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 step is preferably accomplished by ultrasonic welding. In the case of the line production of thermoplastic bags wherein a continuous web of plastic material 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. |
