摘要 |
In the manufacture of plastic bags having interlocking profiled extrusions for the closure, the extruded plastic profile is applied to the moving web of film immediately after extrusion of the profile. The temperature of the moving web is maintained such that the profile adheres to the moving web upon contact and thereafter cools to set the thermoplastic in the desired profile. The moving web of film is maintained under tension so that contraction of the film upon release compensates for the contraction of the locking profile as it cools to prevent puckering of the web. The locking profile is applied to the web in an in-line process which includes folding and heat sealing the moving web of film to form plastic bags.
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