Resin impregnated filter media

Abstract

The present invention discloses a filter medium and a method of manufacturing a filter medium. The filter medium is created using a fabric substrate of a woven or non woven material. The substrate is impregnated with a thermosetting resin that is subsequently heat cured thereby encapsulating the fibers of the substrate. Further a rheology modifier may be mixed with the resin before impregnation to control the flow properties of the resin.

1 . A process of manufacturing a filter medium, comprising: 
 impregnating a substrate with thermosetting resin said substrate being formed from intertwined yarns; and    subsequently curing the thermosetting resin by heating the impregnated substrate to the curing temperature of the resin used, to thereby encapsulate the yarns of the substrate with the resin so that the yarns are mutually bonded where they contact each other.    
     
     
         2 . A process according to  claim 1  said resin is mixed with a rheology modifier before application to control the viscosity and flow properties of the resin.  
     
     
         3 . A process according to  claim 2  wherein the rheology modifier comprises below 5% of the resin composition by weight.  
     
     
         4 . A process according to  claim 2  wherein the rheology modifier comprises hydroxyl-ethyl cellulose.  
     
     
         5 . A process according to  claim 2  wherein the resin is diluted to below 15% solids content before addition of the rheology modifier.  
     
     
         6 . A process according to  claim 2  wherein the thermosetting resin is selected from the group consisting of: phenolic, epoxy, formaldehyde, amino furan, melamine, silicone, unsaturated polyether, polyurethane, polyamide, fluorocarbon based thermosetting resin, cross linked thermoplastic based thermosetting resin and mixtures thereof.  
     
     
         7 . A process according to  claim 1  wherein the substrate is selected from the group consisting of: woven fabric, non-woven fabric, spun bonded yarns, thermo-bonded yarns, and melt blown polymeric yarns.  
     
     
         8 . A process according to  claim 7  wherein the polymeric yarns are a blend of two or more materials selected from the group consisting of: polyester, polypropylene, polyamide, polyethylene, and polyurethane.  
     
     
         9 . A process according to  claim 7  wherein the substrate includes a metal or ceramic mesh screen.  
     
     
         10 . A process according to  claim 1  wherein the coated fabric is subjected to an intermediate heating, before curing to a temperature below the curing temperature to remove water or other solvent.  
     
     
         11 . A filter medium comprising a substrate of a fabric impregnated with a thermosetting resin cured by subsequent heating of the impregnated substrate to the curing temperature of the resin.  
     
     
         12 . A filter medium according to  claim 11  wherein said resin contains a rheology modifier to control the viscosity and flow properties of the resin.  
     
     
         13 . A filter medium according to  claim 12  wherein the rheology modifier comprises below 5% of the resin composition by weight.  
     
     
         14 . A filter medium according to  claim 12  wherein the rheology modifier comprises hydroxyl-ethyl cellulose.  
     
     
         15 . A filter medium according to  claim 12  wherein the resin is diluted to below 15% solids content before addition of the rheology modifier.  
     
     
         16 . A filter medium according to of  claim 11  wherein the thermosetting resin is selected from the group consisting of: phenolic, epoxy, formaldehyde, amino furan, melamine, silicone, unsaturated polyether, polyurethane, polyamide, fluorocarbon based thermosetting resin, cross linked thermoplastic based thermosetting resin and mixtures thereof.  
     
     
         17 . A filter medium according to  claim 11  wherein the substrate is selected from the group consisting of: woven fabric, non-woven fabric, spun bonded yarns, thermo-bonded yarns, and melt blown polymeric yarns.  
     
     
         18 . A filter medium according to  claim 17  wherein the polymeric yarns are a blend of two or more materials selected from the group consisting of: polyester, polypropylene, polyamide, polyethylene, and polyurethane.  
     
     
         19 . A filter medium according to  claim 17  wherein the substrate includes a metal or ceramic mesh screen.