Elastic fastener

Abstract

An elastic web of material has a multiplicity of stems extending from at least one side of the web. The web includes a first continuous layer of elastic material having a first side and a second side and a second layer of material. The second layer of material has a first side which faces the first side of the first layer and a second side from which the stems extend. The first and second layers of material are joined together. The second layer of material can be formed of thermoplastic material or melt processable polymeric material. The first and second layers of material are melt formed. They are joined by coextrusion or lamination to form a multiple layer sheet on which a multiplicity of stems are formed on at least the second layer by a process such as embossing the stems into the heated web using a patterned roll or mold.

We claim:  
     
         1 . A method of making a web material having a plurality of stems extending from at least one side of the web, comprising the steps of melt forming two layers and forming a plurality of stems on at least one surface, which method is characterized by: 
 (a) melt forming, from an elastomeric material, a first layer ( 16 ) having a first surface and a second surface; 
 (b) melt forming, from a second material, a continuous second layer ( 14 ) having a first surface and a second surface;  
 (c) joining the first surfaces of first and second layers to form a sheet wherein said first layer is continuous; and  
 (d) forming a plurality of stems ( 12 ) on at least the second surface of the second layer ( 14 ) of material.  
   
     
     
         2 . The method of  claim 1  wherein said elastomeric material comprising said first layer is selected from the group consisting of: natural and synthetic rubbers, styrene block copolymers containing isoprene, butadiene, or ethylene(butylenes) blocks, metallocene-catalyzed polyolefins, polyurethanes and polydiorganosiloxanes, and said second material comprises a thermoplastic material.  
     
     
         3 . The method of  claim 2  wherein said thermoplastic material is selected from the group consisting of: polyolefins, polystyrenes, polycarbonates, polymethyl methacrylate, ethylene vinyl acetate copolymers, acrylate modified ethylene vinyl acetate polymers, and ethylene acrylic acid copolymers.  
     
     
         4 . The method of  claim 1  further comprising adding a reactive tie layer between the first and the second layers, said reactive tie layer being selected from the group consisting of (1) the reaction product of reactive functionalities in the first and second layers that react where the first side of the first layer contacts the first side of the second layer and (2) a polymer comprising segments that have preferential affinity for the material of the first layer or material of the second layer.  
     
     
         5 . The method of  claim 1  further comprising coating an adhesive material on at least a portion of said stems.  
     
     
         6 . The method of  claim 1  further comprising applying at least one additional layer to the outer surface of the multiple layer sheet wherein said additional layer has a surface bearing a multiplicity of loops.  
     
     
         7 . The method of  claim 1  wherein the stem forming step comprises pressing the sheet from step (c) against at least one temperature controlled surface containing an array of holes to form an array of stems.  
     
     
         8 . The method of  claim 7  further comprising forming caps on one or more of the stems by pressing the stems against a heated surface to form caps on the tips of the stems.  
     
     
         9 . The method of  claim 1  wherein the stem forming step comprises: 
 (1) passing the sheet from step (c) through a shaped die to form a plurality of raised ribs on at least one surface of the multiple layer sheet;  
 (2) passing a plurality of sharp edges perpendicularly through the ribs; and  
 (3) stretching the multiple layer sheet to separate each rib into a plurality of stems.  
 
     
     
         10 . The method of  claim 1  wherein step (d) comprises forming the plurality of stems of at least the second material and the method further comprises the step of selecting relative quantities of the first and second materials such that the fist material which forms the first layer protrudes into or through and forms part of the stems formed on the second surface of the second layer.