Moisture barrier paper and process for making the same

Abstract

A moisture barrier paper is comprised of a fiber mat and a unique moisture barrier coating. The moisture barrier coating coats substantially every fiber throughout the fiber mat. The moisture barrier paper is created in a wet-end, on-machine process where a liquid, moisture barrier coating is sprayed onto a forming fiber mat and is drawn through the fibers with vacuum. The moisture barrier paper has top and bottom surfaces that are substantially free of wax and polymeric water repellants. The moisture barrier paper is completely repulpable.

What is claimed:  
     
         1 . A moisture barrier pulp product, comprising: 
 at least one ply of a fiber mat, said fiber mat comprising a plurality of top surface fibers, a plurality of bottom surface fibers and a plurality of intermediate fibers, said plurality of intermediate fibers intermediate and unitarily joined to said plurality of top surface fibers and bottom surface fibers, and wherein a substantial portion of said plurality of top surface fibers, said plurality of bottom surface fibers and said plurality of intermediate fibers are unitary with a moisture barrier coating.    
     
     
         2 . The moisture barrier pulp product of  claim 1 , wherein said moisture barrier coating is substantially wax free.  
     
     
         3 . The moisture barrier pulp product of  claim 1 , wherein said moisture barrier coating is substantially free of polymeric water-repellants.  
     
     
         4 . The moisture barrier pulp product of  claim 1 , wherein said at least one ply of a fiber mat with said moisture barrier coating has a water vapor transmission rate of less than 5.  
     
     
         5 . The moisture barrier pulp product of  claim 1 , wherein said at least one ply of a fiber mat with said moisture barrier coating has a water vapor transmission rate of less than 1.  
     
     
         6 . The moisture barrier pulp product of  claim 1 , said moisture barrier pulp product further comprising at least two plies of fiber mats.  
     
     
         7 . The moisture barrier pulp product of  claim 1 , wherein said at least one ply of a fiber mat with said moisture barrier coating is completely repulpable.  
     
     
         8 . The moisture barrier pulp product of  claim 1 , wherein said moisture barrier pulp product comprises a linerboard pulp product.  
     
     
         9 . A moisture barrier pulp product, comprising: 
 at least two plies of fiber mats, wherein the fibers of said at least two plies of fiber mats are unitarily joined such that the joined fiber mats comprise a plurality of top surface fibers, a plurality of bottom surface fibers and a plurality of intermediate fibers, said intermediate fibers intermediate to and unitarily joined to said plurality of top surface fibers and bottom surface fibers, and wherein a substantial portion of said top surface fibers, said plurality of bottom surface fibers and said plurality of intermediate fibers are unitary with a moisture barrier coating.    
     
     
         10 . The moisture barrier pulp product of  claim 9 , wherein said at least two plies of fiber mats comprise a top fiber mat and a bottom fiber mat, and wherein said bottom fiber mat comprises in the range of 50% to 80% of a basis weight of the moisture barrier pulp product and said top fiber mat comprises 20% to 50% of said basis weight of the moisture barrier pulp product.  
     
     
         11 . The moisture barrier pulp product of  claim 10 , wherein said bottom fiber mat comprises approximately 60% of the basis weight of the moisture barrier pulp product and said top mat comprises approximately 40% of the basis weight of the moisture barrier pulp product.  
     
     
         12 . The moisture barrier pulp product of  claim 9 , wherein said moisture barrier coating is substantially wax free.  
     
     
         13 . The moisture barrier pulp product of  claim 9 , wherein said moisture barrier coating is substantially free of polymeric water repellants.  
     
     
         14 . The moisture barrier pulp product of  claim 9 , wherein said at least two plies of fiber mats with said moisture barrier coating has a water vapor transmission rate of less than 5.  
     
     
         15 . The moisture barrier pulp product of  claim 9 , wherein said at least two plies of fiber mats with said moisture barrier coating is completely repulpable.  
     
     
         16 . The moisture barrier pulp product of  claim 9 , wherein said moisture barrier pulp product comprises a linerboard pulp product.  
     
     
         17 . A process for making a moisture barrier pulp product, comprising the steps of: 
 depositing a slurry of paper-making fibers and liquid onto a moving wire;    draining a portion of the liquid from the slurry to form a fiber mat;    spraying said fiber mat with a liquid, moisture barrier coating; and    applying suction to said fiber mat to draw said liquid, moisture barrier coating through the fibers of said fiber mat.    
     
     
         18 . The process of  claim 17 , wherein said liquid, moisture barrier coating is substantially wax free.  
     
     
         19 . The process of  claim 17 , wherein said liquid, moisture barrier coating is substantially free of polymeric water repellants.  
     
     
         20 . The process of  claim 17 , wherein said step of draining comprises draining a portion of the liquid from the slurry to form a fiber mat having a consistency in the range of 8% to 24% fibers and 76% to 92% liquid.  
     
     
         21 . The process of  claim 17 , wherein said step of draining comprises draining a portion of the liquid from the slurry to form a fiber mat having a consistency in the range of 15% to 18% fibers and 82% to 85% liquid.  
     
     
         22 . The process of  claim 17 , wherein said step of applying suction to said fiber mat further comprises applying suction to said fiber mat to produce a fiber mat having a consistency in the range of 24% to 30% fibers and 70% to 76% liquid.  
     
     
         23 . The process of  claim 17 , wherein said step of applying suction to said fiber mat to draw said liquid, moisture barrier coating through the fibers of said fiber mat further comprises drawing said liquid, moisture barrier coating through the fibers to coat substantially every fiber in said fiber mat with said liquid, moisture barrier coating.  
     
     
         24 . A process for making a moisture barrier pulp product, comprising the steps of: 
 depositing a slurry of paper-making fibers and liquid onto a first moving wire;    depositing a slurry of paper-making fibers and liquid onto a second moving wire;    draining a portion of the liquid from the slurry on the first moving wire to form a base fiber mat;    draining a portion of the liquid from the slurry on the second moving wire to form a top fiber mat;    spraying said base fiber mat with a liquid, moisture barrier coating after said step of draining;    joining said top fiber mat to said base fiber mat to form a unitary fiber mat after said step of spraying; and    applying suction to said unitary fiber mat to draw said liquid, moisture barrier coating through the fibers of said unitary fiber mat.    
     
     
         25 . The process of  claim 24 , wherein the step of joining comprises pressing said top fiber mat to said base fiber mat.  
     
     
         26 . The process of  claim 24 , the step of joining said top fiber mat to said base fiber mat to form a unitary fiber mat after spraying, wherein the fibers of said top fiber mat are adapted to wick up a portion of said liquid, moisture barrier coating.  
     
     
         27 . The process of  claim 24 , wherein said liquid, moisture barrier coating is substantially wax free.  
     
     
         28 . The process of  claim 24 , wherein said liquid, moisture barrier coating is substantially free of polymeric water repellants.  
     
     
         29 . The process of  claim 24 , wherein the step of draining to form a base fiber mat comprises draining a portion of the liquid from the slurry on the first moving wire to form a base fiber mat having a consistency in the range of 8% to 24% fibers and 76% to 92% liquid.  
     
     
         30 . The process of  claim 24 , wherein the step of draining to form a base fiber mat comprises draining a portion of the liquid from the slurry on the first moving wire to form a base fiber mat having a consistency in the range of 15% to 18% fibers and 82% to 85% liquid.  
     
     
         31 . The process of  claim 24 , wherein the step of draining to form a top fiber mat comprises draining a portion of the liquid from the slurry on the second moving wire to form a top fiber mat having a consistency in the range of 8% to 20% fibers and 80% to 92% liquid.  
     
     
         32 . The process of  claim 24 , wherein the step of draining to form a top fiber mat comprises draining a portion of the liquid from the slurry on the second moving wire to form a top fiber mat having a consistency in the range of 17% to 20% fiber and 80% to 83% liquid.  
     
     
         33 . The process of  claim 24 , wherein said step of applying suction to said unitary fiber mat to draw said liquid, moisture barrier coating through the fibers of said unitary fiber mat further comprises drawing said liquid, moisture barrier coating through the fibers to coat substantially every fiber in said unitary fiber mat with said liquid, moisture barrier coating.  
     
     
         34 . The process of  claim 24 , wherein said base fiber mat comprises in the range of 50% to 80% of a basis weight of the moisture barrier pulp product and said top fiber mat comprises 20% to 50% or said basis weight of the moisture barrier pulp product.  
     
     
         35 . The process of  claim 24 , wherein said base fiber mat comprises approximately 60% of a basis weight of the moisture barrier pulp product and said top fiber mat comprises approximately 40% of the basis weight of the moisture barrier pulp product.  
     
     
         36 . The process of  claim 24 , wherein said moisture barrier pulp product is a moisture barrier linerboard pulp product.