Wood Pulp Paper with High Antimicrobial Barrier Level

Abstract

Wood pulp papers are provided that are useful in end uses requiring microbial barrier properties such as medical packaging, air filters, liquid filters, and other uses and the papers have significantly improved bacterial barrier properties in contrast to wood pulp papers known in the art as measured by Log Reduction Values determined by ASTM F-1608.

1 . A multi-ply paper structure, wherein at least one ply is a paper having a Log Reduction Value of at least 3.6 as determined by ASTM F 1608, a density of at least 0.80 g/cm 3 , and a basis weight of at least about 55 g/m 2 , the paper being formed from a fibrous component consisting essentially of wood pulp, wherein the wood pulp is refined pulp having a Canadian Standard Freeness of less than 360 ml and a weight-weighted mean length of less than 3 mm. 
   
   
       2 . The multi-ply paper according to  claim 1 , wherein the multi-ply paper is coated on an entire surface thereof or in selected areas with a heat-seal composition. 
   
   
       3 . The multi-ply paper of  claim 1 , wherein the multi-ply paper is calendered. 
   
   
       4 . The multi-ply paper according to  claim 1 , wherein the multi-ply paper has a Gurley of no greater than about 250 seconds. 
   
   
       5 . A multi-ply paper, comprising a first ply comprising the wood pulp paper according to  claim 1  sandwiched between second and third plies of paper comprising wood pulp, wherein the wood pulp in the second and third plies comprise fibers having a weight-weighted mean length of at least about 3 mm and wherein the multi-ply paper has been calendered. 
   
   
       6 . The multi-ply paper of  claim 5 , wherein the second and third plies further comprise up to about 70 weight percent of synthetic fibers.