Method for extrusion coating a lightweight web

Abstract

The specification discloses a method for extrusion coating a lightweight web. According to the method, a length of a lightweight web along with a length of a carrier web is fed to an extruder with the lightweight web positioned atop the carrier web. A polymer film is then extruded onto the combined lightweight web and carrier web to provide an extrusion-coated lightweight web. Thereafter, the extrusion-coated lightweight is separated from the carrier web. Also disclosed are extrusion-coated lightweight webs formed according to the method.

What is claimed is:  
     
         1 . A method for extrusion coating a lightweight web comprising: 
 feeding a length of a lightweight web along with a length of carrier web to an extruder with the lightweight web atop the carrier web;    extruding a polymer film coating onto the lightweight web and carrier web in the extruder so that a surface of the lightweight web is coated by the extruded coating to provide an extrusion-coated lightweight web; and    separating the extrusion-coated lightweight web from the carrier web.    
     
     
         2 . The method of  claim 1  wherein the lightweight web has a width less than the width of the carrier web and is affixed to the carrier web by the polymer film coating.  
     
     
         3 . The method of  claim 1  wherein the lightweight web exhibits deformations when subjected to a tension of about 0.5 pli or less.  
     
     
         4 . The method of  claim 1  wherein the polymer film coating comprises a polymer selected from the group consisting of low density polyethylene (LDPE), polyolefin plastomers (POP), polyolefin elastomers (POE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE), polypropylene (PP), ethylene methyl acrylate copolymer (EMA), ethylene butyl acrylate copolymer (EnBA), ethylene vinyl acetate copolymer (EVA), ethylene acrylic acid copolymer (EAA), ethylene methyl acrylic acid copolymer (EMAA), ionomoers, ethylene vinyl alcohol (EVOH), polyesters such as polyethylene terephthalate (PET), polyamides, and one or more of the foregoing.  
     
     
         5 . The method of  claim 1  wherein the lightweight web is a nonwoven fabric.  
     
     
         6 . The method of  claim 1  wherein the lightweight web is a paper web.  
     
     
         7 . The method of  claim 1  wherein the lightweight web is a metal foil.  
     
     
         8 . The method of  claim 1  wherein the lightweight web has a MD curl of less than about 3 inches as measured by TAPPI UM 427.  
     
     
         9 . The method of  claim 1  wherein the lightweight web has insufficient strength properties in the absence of the underlying carrier web to withstand forces imposed upon it in an extruder coating station.  
     
     
         10 . The method of  claim 1  wherein the carrier web is a heavyweight web.  
     
     
         11 . The method of  claim 1  wherein the carrier web is a second lightweight web.  
     
     
         12 . The method of  claim 1  wherein the polymer film coating comprises a coextrusion of at least two layers of polymer films.  
     
     
         13 . A coated web product comprising: 
 a lightweight web; and    a polymer coating extrusion coated thereon wherein the lightweight web is substantially undeformed.    
     
     
         14 . The product of  claim 13  wherein the lightweight web is a nonwoven fabric.  
     
     
         15 . The product of  claim 13  wherein the lightweight web is a paper web.  
     
     
         16 . The product of  claim 13  wherein the lightweight web is a metal foil.  
     
     
         17 . The product of  claim 13  wherein the lightweight web exhibits deformations when subjected to a tension of about 0.5 pli or less.  
     
     
         18 . The product of  claim 13  wherein the lightweight web has a MD curl of less than about 3 inches as measured by TAPPI UM 427.  
     
     
         19 . The product of  claim 13  wherein the polymer coating extruded onto the lightweight web is a polymeric film comprising a polymer selected from the group consisting of extruded low density polyethylene (LDPE), polyolefin plastomers (POP), polyolefin elastomers (POE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE), polypropylene (PP), ethylene methyl acrylate copolymer (EMA), ethylene butyl acrylate copolymer (EnBA), ethylene vinyl acetate copolymer (EVA), ethylene acrylic acid copolymer (EAA), ethylene methyl acrylic acid copolymer (EMAA), ionomoers, ethylene vinyl alcohol (EVOH), polyesters such as polyethylene terephthalate (PET), polyamides, and one or more of the foregoing.  
     
     
         20 . The product of  claim 13  wherein the polymer coating comprises a coextrusion of at least two layers of polymer films.  
     
     
         21 . A product formed according to the method of  claim 1.