Plastic biodegradable reclosable zipper for flexible packages

Abstract

A fastener for a reclosable container is constructed of a biodegradable material. The fastener includes two tracks that interlock to close the container. The fastener may include flanges to prevent damage to other portions of the container. The material may contain a small percentage of starch to permit the fastener to biodegrade within a few years after the container has been discarded. The remainder of the container may also be constructed of a biodegradable material.

1 . A fastener for a container comprising: 
 a first track having a first base and a joining surface extending therefrom; and    a second track having a second base and a engaging surface extending therefrom, wherein said joining surface and said engaging surface matingly engage to releasably fasten said first base to said second base, and wherein said first track and said second track are biodegradable.    
   
   
       2 . The fastener of  claim 1 , wherein said fastener is constructed of a starch and a polymer.  
   
   
       3 . The fastener of  claim 2 , wherein said polymer is selected from the group consisting of polyethylene and polypropylene.  
   
   
       4 . The fastener of  claim 1 , wherein said biodegradable track is about 0.001 to about 10 weight percent of said fastener.  
   
   
       5 . The fastener of  claim 2 , wherein said starch is about 1 to about 5 weight percent of said fastener.  
   
   
       6 . The fastener of  claim 2 , wherein said starch is blended with said polymer to form a material that may be extruded.  
   
   
       7 . The fastener of  claim 1 , wherein at least one of said first track and said second track has a rib extending therefrom and said rib extends generally along a transverse direction forming generally a planar surface.  
   
   
       8 . The fastener of  claim 1 , wherein at least one of said joining surface and said engaging surface includes a transversely extending rib.  
   
   
       9 . The fastener of  claim 1 , wherein said first track has a generally consistent cross section along a longitudinal length.  
   
   
       10 . A container comprising: 
 a film enclosure wall; and    a fastener coupled to said wall, wherein said fastener selectively encloses at least a portion of said container and at least a portion of said fastener is biodegradable.    
   
   
       11 . The container of  claim 10 , wherein said fastener is welded to said wall.  
   
   
       12 . The container of  claim 10 , wherein at least a portion of said wall is biodegradable.  
   
   
       13 . The container of  claim 10 , wherein said fastener selectively seals said container.  
   
   
       14 . The container of  claim 10 , further comprising a second film enclosure wall.  
   
   
       15 . The container of  claim 14 , wherein said second film enclosure wall is sealed to said first enclosure wall at least along two edges, and said fastener is welded to said second enclosure wall.  
   
   
       16 . The container of  claim 10 , wherein said fastener is constructed of a starch and a polymer.  
   
   
       17 . The container of  claim 10 , wherein said fastener includes: 
 a first track having a first base and a joining surface extending therefrom; and    a second track having a second base and a complementary engaging surface extending therefrom, wherein said joining surface and said engaging surface matingly engage to releasably fasten said first base to said second base.    
   
   
       18 . The container of  claim 17 , wherein said first track has a generally consistent cross section along a longitudinal length.  
   
   
       19 . A method of manufacturing a fastener comprising the steps of: 
 forming a first track having a first base and a joining surface extending therefrom; and    forming a second track having a second base and a complementary engaging surface extending therefrom, wherein said joining surface and said engaging surface matingly engage to releasably fasten said first base to said second base, and wherein at least one of said first track and said second track is biodegradable.    
   
   
       20 . The method of  claim 19 , further comprising blending a starch and a polymer to form a material for said fastener.  
   
   
       21 . The method of  claim 19 , wherein each of said steps of forming include extrusion.