Coated sheet materials and packages made therewith

Abstract

A coated porous sheet material comprising a gas permeable sheet material selected from the group consisting of flash spun plexifilamentary nonwoven sheet, spunbonded-film-spunbonded composite sheet, spun-laced polyester/wood pulp composite sheet and paper and a polymeric coating on at least one side thereof, wherein the permeability of the coated sheet material is substantially equivalent to the permeability of an equivalent sheet material without the coating. The coated porous sheet material is suitable for use in heat sealable packages.

What is claimed is:  
     
         1 . A heat sealable package comprising: 
 a first material which comprises a fibrous sheet, said first material having a coating covering at least one side, said coating comprising polyacrylate having a thickness between about 0.05 and about 5 μm; and    a second material;    wherein portions of the coated side of the first material can be heat-sealed to the second material such that the first material and the second material cooperate to form a void capable of containing an article.    
     
     
         2 . The heat sealable package of  claim 1 , wherein the polyacrylate of the coating is selected such that when the sealed package is opened by separating the first material and the second material, substantially no fiber tear results.  
     
     
         3 . The heat sealable package of  claim 1 , wherein the coating comprises a first layer of cross-linked polyacrylate and a second layer comprising a compound selected from the group consisting of hydrocarbon oligomers and mixtures of polyacrylates and hydrocarbon oligomers.  
     
     
         4 . The heat sealable package of  claim 1 , wherein the coating comprises a first layer of cross-linked thermoset polymer and a second layer of a heat sealable compound, and wherein when heat sealed, the adhesion strength between the first layer and the first material is greater than 350.3 N/m, the adhesion strength between the first layer and the second layer is between 140.1 and 350.3 N/m and the adhesion strength between the second layer and the second material is between 175.1 and 350.3 N/m.  
     
     
         5 . The heat sealable package of  claim 1 , wherein the second material is a nonwoven fabric.  
     
     
         6 . The heat sealable package of  claim 1 , wherein the second material is a coated film.  
     
     
         7 . The heat sealable package of  claim 1 , wherein the second material is a thermoformable film.  
     
     
         8 . The heat sealable package of  claim 1 , wherein the second material is a rigid preformed tray.  
     
     
         9 . The heat sealable package of  claim 1 , wherein the second material is paper.  
     
     
         10 . The heat sealable package of  claim 1 , wherein the coating covers fibers of said fibrous sheet while leaving interstitial spaces between said fibers substantially uncovered.  
     
     
         11 . The heat sealable package of  claim 1 , wherein said fibrous sheet is selected from the group consisting of flash spun plexifilamentary nonwoven sheet, spunbonded-meltblown-spunbonded composite sheet and fibrous paper.  
     
     
         12 . A heat sealed package made from the heat sealable package of any of claims  1 - 11 .  
     
     
         13 . The heat sealed package of  claim 12 , wherein the heat seal between the first material and the second material has a seal strength of 140.1 to 350.3 N/m.