Reclosable packaging with gas barrier incorporated in zipper

Abstract

A flexible zipper incorporating a layer of gas-impermeable thermoplastic material in one or both flanges. The zipper is installed in the mouth of a reclosable package or bag made of gas-impermeable material shaped to form a receptacle. The gas-impermeable web material of the receptacle and the layer of gas-impermeable material of the zipper form a substantially gastight enclosure for preserving the perishable contents of the package. Flexible zippers having a layer of gas-impermeable thermoplastic material joined to a layer of gas-permeable thermoplastic material are preferably manufactured by a coextrusion process. The resulting gas barrier inside the receptacle has a zone of preferential tearing.

1 - 27 . (Canceled).  
   
   
       28 . A flexible zipper comprising first profiled member, a second profiled member interlockable with said first profiled interlocking member, a continuous layer of gas-permeable thermoplastic material having one end connected to said first profiled member and having another end connected to said second profiled interlocking member, a continuous layer of gas-impermeable thermoplastic material laminated to said layer of gas-permeable thermoplastic material to form a continuous laminated web depending from said first and second profiled interlocking members, wherein said laminated web has a thinned area extending in a lengthwise direction.  
   
   
       29 . A reclosable package comprising: 
 a receptacle having an interior volume and a mouth, said receptacle comprising first and second walls joined to each other along first and second side seams of said receptacle; and    a zipper joined to said first and second walls at or near said mouth, said zipper comprising first and second profiled members that are mutually interlockable, a continuous layer of gas-permeable thermoplastic material having one end connected to said first profiled member and another end connected to said second profiled interlocking member, a continuous layer of gas-impermeable thermoplastic material laminated to said layer of gas-permeable thermoplastic material to form a continuous laminated web, wherein said laminated web has a thinned area extending in a lengthwise direction from one end of said laminated web to an opposite end thereof, said thinned area being disposed inside said interior volume of said receptacle at an elevation below the elevations where said zipper is joined to said first and second walls, wherein said layer of gas-impermeable thermoplastic material extends from a region where said laminated web is joined to said first wall to a region where said laminated web is joined to said second wall    
   
   
       30 . The package as recited in  claim 29 , further comprising a slider mounted to said zipper.  
   
   
       31 . The package as recited in  claim 30 , further comprising a header covering said slider and said zipper.  
   
   
       32 . A reclosable package comprising: 
 a receptacle having an interior volume and a mouth, said receptacle comprising first and second walls joined to each other along first and second side seams of said receptacle; and    a zipper joined to said first and second walls at or near said mouth, said zipper comprising first and second profiled members that are mutually interlockable, a layer of gas-permeable thermoplastic material having one end connected to said first profiled member and another end connected to said second profiled interlocking member, a continuous layer of gas-impermeable thermoplastic material laminated to said layer of gas-permeable thermoplastic material to form a laminated web, wherein said layer of gas-permeable thermoplastic material has a line of weakened tear resistance extending in a lengthwise direction from one end of said laminated web to an opposite end thereof, said line of weakened tear resistance being disposed inside said interior volume of said receptacle at an elevation below the elevations where said zipper is joined to said first and second walls, wherein said layer of gas-impermeable thermoplastic material extends from a region where said laminated web is joined to said first wall to a region where said laminated web is joined to said second wall    
   
   
       33 . The package as recited in  claim 32 , wherein said line of weakened tear resistance comprises a scoreline.  
   
   
       34 . The package as recited in  claim 32 , wherein said line of weakened tear resistance comprises a series of spaced perforations.  
   
   
       35 . The package as recited in  claim 32 , further comprising a slider mounted to said zipper.  
   
   
       36 . The package as recited in  claim 33 , further comprising a header covering said slider and said zipper.