Filter medium, manufacturing method therefor, and filter equipment using same

Abstract

Provided are a filter medium, a manufacturing method thereof, and a filter apparatus using the filter medium. The filter medium includes: a porous substrate; a nanofiber web that is laminated on both sides of the porous substrate, and that has a number of fine pores formed by electrospinning a polymer material; and an adhesive unit for adhering the porous substrate and the nanofiber web integrally, wherein the adhesive unit is achieved by applying heat whose temperature is lower than the melting point of the porous substrate and higher than the melting point of the nanofiber web.

1 . A filter medium comprising:
 a porous substrate;   a nanofiber web that is laminated on both sides of the porous substrate, and that has a number of fine pores formed by electro spinning a polymer material; and   an adhesive unit for adhering the porous substrate and the nano fiber web integrally,   wherein the adhesive unit has a thermally fusing structure that is achieved by applying heat whose temperature is lower than the melting point of the porous substrate and higher than the melting point of the nanofiber web.   
     
     
         2 . The filter medium according to  claim 1 , wherein the porous substrate is a nonwoven fabric of any one of a polyester-based, nylon-based, polyolefin-based and cellulose-based nonwoven fabric, and the polymer material forming the nanofiber web comprises a polyvinylidene fluoride (PVdF). 
     
     
         3 . The filter medium according to  claim 2 , wherein the polymer material is a mixture of PVdF and polyacrylonitrile (PAN) at a ratio of 5:5 or 6:4. 
     
     
         4 . The filter medium according to  claim 2 , wherein the thermally fusing structure is a structure that ⅕ to ½ the thickness of the nano fiber web is melted and penetrated and bonded to the nonwoven fabric. 
     
     
         5 . The filter medium according to  claim 2 , wherein the nanofiber web has a structure that the nanofiber web is laminated on the entire surface except for the upper surface of the nonwoven fabric. 
     
     
         6 . The filter medium according to  claim 1 ,
 wherein the nanofiber web comprises a first nanofiber web layer that is formed by electrospinning a low-concentration polymer material mixture solution and a second nanofiber web layer that is formed by electrospinning a high-concentration polymer material mixture solution; and   wherein the low-concentration polymer material mixture solution contains a polymer material of 8˜10 wt %, and the high-concentration polymer material mixture solution contains a polymer material of 15˜17 wt %.   
     
     
         7 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . A filter medium comprising:
 a porous substrate;   a nanofiber web that is laminated on both sides of the porous substrate, and that has a number of fine pores formed by electro spinning a polymer material; and   an adhesive unit for adhering the porous substrate and the nano fiber web integrally,   wherein the adhesive unit is a hot-melt powder or hot-melt web.   
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . A method of manufacturing a filter medium comprising the steps of:
 preparing a nonwoven fabric;   electrospinning a polymer material on a release paper, to thus form a nanofiber web; and   laminating and thermally fusing the nanofiber web via a hot-melt powder or hot-melt web on both surfaces of the nonwoven fabric.   
     
     
         15 . (canceled) 
     
     
         16 . A filter apparatus comprising:
 a housing having an inlet and an outlet for sewage or waste water;   a plurality of filter media that are arranged at a predetermined interval in the housing, and for filtering the waste water stored in the housing according to  claim 1 ; and   a pump that is connected to the outlet for pumping the water of the housing, or supplying wash water into the housing.   
     
     
         17 . The filter apparatus according to  claim 16 , further comprising a nozzle for generating bubbles, which is provided at one side of the housing and washes a filter medium.