Compressed nanofiber composite media

Abstract

A coalescing media includes a compressed composite filter media comprising substrate layers and hydrophilic fine fiber layers for separating free water emulsified in fuels.

1 . A method of forming a coalescing filter media, comprising steps of:
 electrostatically spinning fine fibers having an average diameter of less than 1 micron;   applying the fine fibers to at least one substrate comprising coarse fibers having an average diameter greater than 1 micron;   compacting the fine fibers and the coarse fibers together;   generating sufficient fine fiber coverage and tightness through said compacting to provide coalescing of water droplets from a fluid stream; and   structuring the coarse fibers and the fine fibers into a coalescing filter media that is operable to remove water from a fluid stream.   
     
     
         2 . The method of  claim 1 , wherein the at least one substrate comprises a fiber entanglement that is bonded together into a formed filter media prior to said applying, the fine fibers deposited onto the formed filter media during said step of applying the fine fibers. 
     
     
         3 . The method of  claim 2 , wherein the at least one substrate comprises at least one scrim formed of bi-component fibers comprising a high melt component and a low melt component, wherein the fine fibers are deposited on a surface of the at least one scrim and carried by the at least one scrim. 
     
     
         4 . The method of  claim 1 , further comprising generating multiple layers of substrate with nanofibers carried on multiple individual layers either by feeding multiple discrete substrate layers or lapping one or more individual substrate layers, thereby spacing fine fibers within the thickness of the coalescing filter media by the multiple layers of substrate, wherein said compacting comprises laminating multiple layers of the substrate carrying the fine fibers, and compressing the multiple layers of the substrate carrying the fine fibers to form a composite filter media. 
     
     
         5 . The method of  claim 4 , further comprising permanently bonding the multiple layers of substrate carrying the fine fibers together to form an integrated composite filter media layer. 
     
     
         6 . The method of  claim 1 , wherein each substrate individually carries the fine fibers along one surface thereof having a fine fiber coverage between about 0.075 g/m 2  and 0.225 g/m 2 , and collectively providing a total fine fiber coverage in the composite filter media between about 0.75 g/m 2  and 2.25 g/m 2  in the coalescing filter media and thereby providing said sufficient fine fiber coverage and tightness. 
     
     
         7 . The method of  claim 6 , wherein the layers are compressed together to reduce a thickness to between about 3/16″ and ½″. 
     
     
         8 . The method of  claim 4 , further comprising laminating a drainage filter layer on or proximate a downstream side of the coalescing filter media, the drainage layer arranged to collect and grow water droplets coalesced by fine fibers. 
     
     
         9 . The method of  claim 5 , wherein the at least one substrate comprises at least one scrim formed of bi-component fibers comprising a high melt component and a low melt component, wherein the fine fibers are deposited on a surface of the at least one scrim and carried by the at least one scrim; further including heating the multiple layers of the scrim carrying the fine fibers to or near a melting temperature of the low melt component, wherein the low melt component melts or softens to act as a bonding agent to bond layers together. 
     
     
         10 . The method of  claim 5 , the scrim carrying the fine fibers are folded into multiple folds and compressed together, wherein the folding creates a fine fiber to fine fiber laminated surface and a scrim to scrim laminated surface. 
     
     
         11 . The method of  claim 1 , wherein the substrate is a web of coarse fibers comprising a loose entanglement of the coarse fibers, the fine fibers being applied to the loose entanglement of the coarse fibers during the said step of applying the fine fibers, and wherein the web of coarse fibers applied with the fine fibers are folded into multiple folds and compressed together, wherein the fine fibers and the coarse fibers are integrated to form a single integrated coalescing media. 
     
     
         12 . The method of  claim 1 , wherein said electrostatically spinning fine fibers comprises spinning fine fibers from a solution including a hydrophilic polymer. 
     
     
         13 . A method of forming a compressed filter media, comprising steps of:
 electrostatically spinning a web of fine fibers having an average diameter of less than 1 micron;   applying the fine fibers to a substrate, the substrate comprising coarse fibers that are bonded together to form a filter media, wherein the coarse fibers have an average fiber diameter greater than 1 micron; and   lapping the combination of the fine fiber applied substrate such that the fine fibers overlap.   
     
     
         14 . The method of  claim 13 , further comprising unwinding a roll of filter media from an unwind station and transferring the filter media to an electrospinning station, wherein the filter media is kept afloat via a line tension. 
     
     
         15 . The method of  claim 13 , wherein the substrate is a scrim comprising bi-component fibers, the bi-component fibers comprising a high melt polyester core and a low melt polyester sheath. 
     
     
         16 . The method of  claim 13 , wherein the step of applying the fine fibers provide a fine fiber coverage between about 0.075 g/m 2  and 0.225 g/m 2 , wherein the fine fibers are carried by a scrim. 
     
     
         17 . The method of  claim 13 , wherein the step of lapping comprises folding the substrate carrying the fine fibers into 2-20 folds, wherein the folding provides a fine fiber to fine fiber laminated surface and a substrate to substrate laminated surface, wherein the folded layers are heated and compressed to form a compressed media, wherein a thickness is adjusted by between about 50% and 300% via heating and compressing. 
     
     
         18 . The method of  claim 17 , wherein the compressed media is formed to have a total fine fiber coverage between about 0.09 g/m 2  and 5.25 g/m 2 . 
     
     
         19 . The method of  claim 13 , wherein the step of electrostatically spinning fine fibers comprises spinning fine fibers from a solution including a polyamide-6. 
     
     
         20 . A coalescing filter media, comprising:
 at least one substrate comprising at least one filter media including coarse fibers having an average fiber diameter of greater than 1 micron;   fine fibers carried by the substrate, the fine fibers comprising hydrophilic fibers having an average fiber diameter of less than 1 micron, the fine fibers providing a sufficient fiber surface area to coalesce emulsified water in a hydrocarbon fuel, wherein the hydrophilic fibers facilitate formation and growth of water droplets.   
     
     
         21 . The coalescing filter media of  claim 20 , further including a drainage layer arranged on a downstream surface of the coalescing filter media, wherein the drainage layer is formed of a hydrophobic porous material. 
     
     
         22 . The coalescing filter media of  claim 21 , wherein the drainage layer is formed of a cellulous material or a fiber glass material. 
     
     
         23 . The coalescing filter media of  claim 20 , wherein the fine fibers are electrospun nanofibers formed of a hydrophilic polymer. 
     
     
         24 . The coalescing filter media of  claim 23 , wherein the fine fibers are formed of a polyamide-6. 
     
     
         25 . The coalescing filter media of  claim 24 , wherein the fine fibers have a total fine fiber coverage between about 0.09 g/m 2  and 5.25 g/m 2 . 
     
     
         26 . The coalescing filter media of  claim 20 , wherein the substrate is a scrim comprising bi-component fibers, the bi-component fibers having a high melt component and a low melt component. 
     
     
         27 . The coalescing filter media of  claim 26 , wherein the bi-component fibers comprise a high melt polyester core and a low melt polyester sheath, wherein the at least one substrate and the fine fibers are heated and compressed together to form a coalescing media, wherein the low melt polyester sheath melts or softens to bond the coarse fibers and the fine fibers. 
     
     
         28 . The coalescing filter media of  claim 20 , wherein the coalescing filter media includes multiple layers of filter media, each of the multiple filter media layers carrying a layer of fine fibers having a fine fiber coverage between about 0.075 g/m 2  and 0.225 g/m 2 . 
     
     
         29 . The coalescing filter media of  claim 28 , wherein each of the fine fiber layer is sandwiched between the substrate layers and/or a media layer. 
     
     
         30 . The coalescing filter media of  claim 29 , wherein the coalescing filter media includes a fine fiber to fine fiber laminated surface and a substrate to substrate laminated surface. 
     
     
         31 . The coalescing filter media of  claim 28 , wherein the coalescing filter media includes 10 layers of substrate, wherein each of the substrate layer is formed of a scrim comprising bi-component fibers, wherein each of the fine fiber layers comprises electrospun polyamide-6 nanofibers, wherein 10 layers of fine fibers provide a total fine fiber coverage between about 0.75 g/m 2  and 2.25 g/m 2 . 
     
     
         32 . The coalescing filter media of  claim 31 , further including a drainage layer arranged on a downstream surface of the coalescing filter media, the drainage layer formed of a fiber glass mat, wherein the coalescing filter media has a total thickness between about 3/16″ and ½″. 
     
     
         33 . A compressed filter media, comprising:
 at least one substrate, the at least one substrate comprising coarse fibers having an average fiber diameter of greater than 1 micron;   fine fibers carried by the at least one substrate, the fine fibers having an average fiber diameter of less than 1 micron, at least some of the fine fibers being embedded at least partially within the coarse fibers in a compressed state.   
     
     
         34 . The compressed filter media of  claim 33 , wherein at least some of the fine fibers form a dimensional matrix of fine fibers as opposed to a planar layer. 
     
     
         35 . The compressed filter media of  claim 33 , wherein at least some of the fine fibers are generally sandwiched between layers of the substrate. 
     
     
         36 . The compressed filter media of  claim 33 , wherein the fine fibers have a melting point higher than a melting point of at least one component of the coarse fibers, and wherein the fine fibers are permanently affixed and oriented 
     
     
         37 . The compressed filter media of  claim 33 , wherein the at least one substrate carrying the fine fibers are calendered together in the compressed state.