Protruding end stops for plastic reclosable fastener
AssigneeMobil Oil Corporation
InventorsF. John Herrington, Jr., Eric A. St. Phillips
Life of this patent
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Abstract
A thermoplastic bag having a zipper that is operated by a slider is provided with end stops that are integral with the ends of the zipper and prevent the slider from going off past the end of the zipper and coming off the bag. There is also disclosed a method for forming these end stops by ultrasonically smashing the ends of the zipper.
Claims7
In the manufacture of thermoplastic bags and the like having a reclosable fastener extending along the mouth of the bag and a slider straddling the fastener for opening and closing the fastener, the fastener comprising a pair of flexible plastic strips secured to the facing side walls of the bag and having reclosable interlocking male and female profile elements on the respective strips, the pair of plastic strips being sealed to each other at the opposite ends of the bag, the improvement comprising:
- end stop means located at the opposite ends of said reclosable fastener, each of said end stop means being formed from the material at the opposite ends of said reclosable fastener and protruding transversely from said fastener a distance adequate to engage the slider and prevent movement of the slider past the respective ends of the bag.
In the manufacture of thermoplastic bag from a pair of superimposed thermoplastic sheets having a top edge with a reclosable fastener extending therealong including a slider for straddling the fastener for opening or closing the fastener, the fastener comprising a pair of flexible plastic strips secured to the facing sidewalls of the bag and having reclosable interlocking male and female profile elements on the respective strips, the method of forming end stops for the slider comprising:
- clamping and sealing together a pair of the flexible plastic strips and the facing side walls at a seal area at the ends of the bag to reduce the material thickness of the pair of flexible plastic strips and the facing side walls of the bag sandwiched therebetween and concurrently increasing the thickness of an adjacent area of the reclosable fastener adjacent the seal area to provide protruding structure from the fastener thereby providing protruding end stops for preventing movement of the slider past the ends of the bag.
Dependencies are inferred from the claim text.