Filter medium, manufacturing method therefor, and filter unit comprising same

Patent metadata

Field	Value
Publication number	US-11364470-B2
Application number	US-201816632630-A
Country	US
Kind code	B2
Filing date	Jul 23, 2018
Priority date	Jul 21, 2017
Publication date	Jun 21, 2022
Grant date	Jun 21, 2022

Abstract

A filter medium including: a porous first support; nanofiber webs respectively stacked at the upper and lower parts of the first support, and made of a plurality of nanofibers of which the diameters have a standard deviation of 300 nm or less; and a porous second support interposed between the first support and the nanofiber web. The filter medium is implemented by fibers having uniform diameters, and thus is easily manufactured to have a predetermined pore diameter and simultaneously has excellent uniformity of the pore diameters, thereby having excellent filtering efficiency and being more suitable when selectively separating specific objects. Backwashing is enabled at uniform pressure during backwashing such that high cleaning power is obtained. The filter medium has excellent water permeability and excellent mechanical strength so as to minimize the shape and structural deformation and damage of the filter medium.

First claim

The invention claimed is:

1. A filter medium comprising:
a porous first support;
nanofiber webs each stacked above and below the first support and formed of a plurality of nanofibers having diameters whose standard deviation is 300 nm or less; and
porous second supports interposed between the first support and the nanofiber webs
wherein each of the second supports includes a second composite fiber including a support component and a low melting point component and disposed such that at least a portion of the low melting point component is exposed at an outer surface thereof, and the low melting point component of the second composite fiber is fused to the nanofiber web,
wherein the first support includes first composite fiber including a support component and a low melting point component and disposed such that at least a portion of the low melting point component is exposed at an outer surface thereof, and the low melting point component of the first composite fiber and the low melting point component of the second composite fiber are fused to each other to bond the first support and the second support,
wherein the nanofiber webs have an average pore diameter of 100 nm to 1000 nm, and
wherein a volume of pores having a pore diameter within the average pore diameter ±10% is 60% or more of the total volume of pores of the nanofiber web.

2. The filter medium of claim 1 , wherein the plurality of nanofibers provided in the nanofiber webs have diameters whose standard deviation is 200 nm or less.

3. The filter medium of claim 1 , wherein the nanofiber has an average fiber diameter of 0.05 μm to 1 μm.

4. The filter medium of claim 1 , wherein a volume of pores having a pore diameter within the average pore diameter ±5% is 45% more of the total volume of pores of the nanofiber web.

5. The filter medium of claim 1 , wherein the nanofiber webs have a porosity of 60% to 90%, a basis weight of 0.05 g/m 2 to 20 g/m 2 , and a thickness of 0.5 μm to 200 μm.

6. The filter medium of claim 1 , wherein the first support and the second support are each independently selected from the group consisting of a non-woven fabric, a fabric, and a knitted fabric.

7. The filter medium of claim 1 , wherein
the first support has a basis weight of 250 g/m 2 to 800 g/m 2 and a thickness of 2 mm to 8 mm, and
the second support has a basis weight of 35 g/m 2 to 80 g/m 2 and a thickness of 150 μm to 250 μm.

8. The filter medium of claim 1 , wherein
the first support has an average fiber diameter of 5 μm to 50 μm, and
the second support has an average fiber diameter of 5 μm to 30 μm.

Assignees

• Amogreentech Co Ltd

Inventors

• Jeong Ui Young
• Seo In Yong

Classifications

• B01D2325/0283

  Pore size · CPC title

• B01D69/1216

  Three or more layers · CPC title

• B01D69/06

  Flat membranes · CPC title

• B01D69/1071

  Woven, non-woven or net mesh · CPC title

• B01D71/381

  Polyvinylalcohol · CPC title