Fibrillated fibers for liquid filtration media

Abstract

Fiber webs which are used in filter media are described herein. In some embodiments, the fiber webs include fibrillated fibers and optionally non-fibrillated fibers, amongst other optional components (e.g., binder resin). In some embodiments, the fiber webs include limited amounts of, or no, glass fiber. The respective characteristics and amounts of the fibrillated fibers are selected to impart desirable properties including mechanical properties and filtration properties (e.g., dust holding capacity and efficiency), amongst other benefits.

What is claimed is: 
     
         1 . A filter media, comprising:
 a fiber web comprising fibrillated fibers and non-fibrillated synthetic fibers, wherein the non-fibrillated synthetic fibers are staple fibers; and   wherein the fiber web has a [mean flow pore (μm)/(permeability (cfm/sf)) 0.5 ] value of greater than or equal to 0.5.   
     
     
         2 . A filter media, comprising:
 a fiber web comprising fibrillated fibers and non-fibrillated synthetic fibers, wherein the non-fibrillated synthetic fibers are staple fibers; and   wherein the fiber web is substantially free of glass fibers.   
     
     
         3 . A filter media, comprising:
 a fiber web comprising fibrillated fibers and non-fibrillated synthetic fibers, wherein the non-fibrillated synthetic fibers are staple fibers; and   wherein the fiber web comprises greater than or equal to 50 wt % non-fibrillated synthetic fibers compared to the total weight of the fiber web.   
     
     
         4 . The filter media of  claim 1 , wherein the fiber web is substantially free of glass fibers. 
     
     
         5 . The filter media of  claim 1 , wherein the fiber web comprises greater than or equal to 50 wt % non-fibrillated synthetic fibers compared to the total weight of the fiber web. 
     
     
         6 . The filter media of  claim 1 , wherein the fiber web has a [mean flow pore (μm)/(permeability (cfm/sf)) 0.5 ] value of less than or equal to 3.0. 
     
     
         7 . The filter media of  claim 1 , wherein the tensile elongation in the machine direction and/or in the cross-machine direction is greater than 0.2%. 
     
     
         8 . The filter media of  claim 1 , wherein the tensile strength in the machine direction and/or the cross-machine direction is greater than 2 N/15 mm. 
     
     
         9 . The filter media of  claim 1 , wherein the fiber web comprises less than or equal to 40 wt % fibrillated fibers compared to the total weight of the fiber web. 
     
     
         10 . The filter media of  claim 1 , wherein the fibrillated fibers comprise lyocell. 
     
     
         11 . The filter media of  claim 1 , wherein the non-fibrillated synthetic fibers have an average diameter of greater than or equal to 1 micron and less than or equal to 15 microns. 
     
     
         12 . The filter media of  claim 1 , wherein the non-fibrillated synthetic fibers have an average length of between 3 mm and 12 mm. 
     
     
         13 . The filter media of  claim 1 , wherein the fiber web comprises bi-component fibers. 
     
     
         14 . The filter media of  claim 1 , wherein the fiber web comprises binder resin. 
     
     
         15 . The filter media of  claim 1 , wherein the fiber web has a basis weight of greater than or equal to 10 g/m 2  and less than or equal to 75 g/m 2 . 
     
     
         16 . The filter media of  claim 1 , wherein the fiber web has an air permeability of greater than or equal to 10 cfm/sf and less than or equal to 250 cfm/sf. 
     
     
         17 . The filter media of  claim 1 , wherein the fiber web has a thickness of less than or equal to 1 mm. 
     
     
         18 . The filter media of  claim 1 , wherein the fiber web has a mean flow pore size of greater than or equal to 2 microns and less than or equal to 50 microns. 
     
     
         19 . The filter media of  claim 1 , wherein the fiber web is wet laid. 
     
     
         20 . The filter media of  claim 1 , wherein the filter media is electrically charged.