Hook fasteners and methods of making the same

Abstract

Methods of making touch fasteners include forming lanes of polymeric material into a sheet-form base and forming discrete elements extending from the sheet-form base. Corresponding touch fasteners are also disclosed.

1 . A touch fastener comprising: 
 a composite polymeric sheet comprising a plurality of longitudinally extending lanes, each lane joined side-by-side to an adjacent lane; and    a plurality of discrete fastener elements comprising stems extending outwardly from at least one exposed surface of the composite sheet, 
 wherein the composite polymeric sheet comprises a first lane comprising a first polymeric material and a second lane comprising a second polymeric material comprising a foam.  
   
   
   
       2 . The touch fastener of  claim 1 , further comprising an engageable head on a distal end of each stem.  
   
   
       3 . The touch fastener of  claim 2 , wherein the engageable head is hook-shaped.  
   
   
       4 . The touch fastener of  claim 1 , wherein the lanes are joined at an interface that comprises the first material and the second material.  
   
   
       5 . The touch fastener of  claim 1 , further comprising an adhesive bonding the adjacent lanes.  
   
   
       6 . The touch fastener of  claim 1 , further comprising a third lane comprising a third material different from the first material and second material.  
   
   
       7 . The touch fastener of  claim 6 , wherein the third lane is disposed between the first lane and second lane, and wherein a first interface comprising the first and third material is defined between the first and third lanes and a second interface comprising the second and third materials is defined between the second and third materials.  
   
   
       8 . The touch fastener of  claim 1 , wherein the plurality of longitudinally extending lanes are formed by coextrusion.  
   
   
       9 . The touch fastener of  claim 1 , wherein the foam is formed by a chemical foaming agent.  
   
   
       10 . The touch fastener of  claim 1 , wherein the foam is formed by injecting gas into the second polymeric material as the second lane is formed.  
   
   
       11 . The touch fastener of  claim 1 , wherein the second polymeric material comprises a thermoset material.  
   
   
       12 . The touch fastener of  claim 1 , wherein the composite polymeric sheet comprises a plurality of lanes comprising first and second materials.  
   
   
       13 . The touch fastener of  claim 12 , wherein the lanes comprising the first and second polymeric materials alternate.  
   
   
       14 . The touch fastener of  claim 1 , wherein the first polymeric material comprises polypropylene.  
   
   
       15 . The touch fastener of  claim 1 , wherein the second polymeric material comprises an elastomer.  
   
   
       16 . The touch fastener of  claim 15 , wherein the elastomer comprises a polypropylene-based thermoplastic vulcanizate.  
   
   
       17 . The touch fastener of  claim 1 , wherein the second lane has a height that is greater than a height of the first lane, each height being measured from a back surface of the respective lane to the top surface of the respective lane.  
   
   
       18 . The method of  claim 1 , wherein the at least one exposed surface of the composite sheet defines a portion of a top surface of the first lane.  
   
   
       19 . A touch fastener comprising: 
 a composite polymeric sheet comprising a plurality of longitudinally extending lanes, each lane joined side-by-side to an adjacent lane; and    a plurality of discrete fastener elements comprising stems extending outwardly from at least one exposed surface of the composite sheet, 
 wherein the composite polymeric sheet comprises a first lane comprising a first polymeric material disposed between a second lane and a third lane, each second and third lane comprising a second polymeric material comprising a foam.  
   
   
   
       20 . The touch fastener of  claim 19 , further comprising a fourth and fifth lane, wherein the forth lane is disposed between the first lane and second lane, and wherein the fifth lane is disposed between the first lane and third lane.