Filter structure with enhanced dirt holding capacity

Patent metadata

Field	Value
Publication number	US-2017173509-A1
Application number	US-201515301781-A
Country	US
Kind code	A1
Filing date	Jun 23, 2015
Priority date	Jun 26, 2014
Publication date	Jun 22, 2017
Grant date	—

Abstract

A fluid filtration device containing a composite filter media having a coarse porous polymeric nonwoven interlayer located between first and second polymeric fiber containing filter mats. The fiber diameters of the fibers in the first and second filter mats are different from each other, and each filter mat has a different pore size rating. The first and second polymeric fibers in the filter mats can be electrospun nanofibers. The interlayer has a coarser pore size when compared to the either the first or second filter mats, such that the resulting composite media has an increased dirt holding capacity compared to filter layers that are layered directly over each other without the presence of a coarse interlayer therebetween.

First claim

What is claimed is:

1 . A composite media comprising:
a porous interlayer having opposing first and second sides, a first fiber containing filter layer located on the first side of the interlayer; and a second fiber containing filter layer located on the second side of the interlayer, wherein the fibers in the first and second fiber containing filter layers have a different fiber diameter, and each fiber containing filter layer has a different pore size rating, and the interlayer has a coarser pore size than either the first or second fiber containing filter layers.

2 . The media according to claim 1 , wherein the fibers in the first and second fiber containing filter layers are a polymer material selected from the group consisting of thermoplastic polymers and thermoset polymers.

3 . The media according to claim 2 , wherein the fibers are nanofibers.

4 . The media according to claim 1 , wherein the interlayer comprises a nonwoven.

5 . The media according to claim 4 , wherein the nonwoven comprises a polymeric nanofiber.

6 . The media according to claim 5 , wherein the polymeric nanofiber is made from polypropylene.

7 . The media according to claim 3 , wherein the nanofibers in the first fiber containing filter layer have a fiber diameter from about 10 nm to about 1,000 nm, and the nanofibers in the second fiber containing filter layer have a fiber diameter from about 10 nm to about 1,000 nm.

8 . The media according to claim 1 , wherein the first and second fiber containing filter layers comprise electrospun nanofiber mats.

9 . The media according to claim 8 , wherein the nanofiber is a polymer material selected from the group consisting of thermoplastic polymers and thermoset polymers.

10 . The media according to claim 8 , wherein the nanofiber is a polymer material selected from the group consisting of thermoplastic polymers, thermoset polymers nylon, polyimide, aliphatic polyamide, aromatic polyamide, polysulfone, cellulose, cellulose acetate, polyether sulfone, polyurethane, poly(urea urethane), polybenzimidazole, polyetherimide, polyacrylonitrile, poly(ethylene terephthalate), polypropylene, polyaniline, poly(ethylene oxide), poly(ethylene naphthalate), poly(butylene terephthalate), styrene butadiene rubber, polystyrene, poly(vinyl chloride), poly(vinyl alcohol), poly(vinyl acetate), poly(vinylidene fluoride), poly(vinyl butylene), copolymers and combinations thereof.

11 . The media according to claim 8 , wherein the nanofiber is a polymer material selected from the group consisting of nylon-6, nylon-6,6, nylon 6,6-6,10, nylon-6 copolymers, nylon-6,6 copolymers, nylon 6,6-6,10 copolymers and mixtures thereof.

12 . The media of claim 1 , wherein the first fiber containing filter layer has a thickness from about 1 μm to about 1,000 μm and the second fiber containing filter layer has a thickness from about 1 μm to about 1,000 μm.

13 . The media of claim 1 , wherein the first and second fiber containing filter layers are selected from the group consisting of gridded filter, curricular shaped filter, disc shaped filter, pleated filter, depth filter and combinations thereof.

14 . The media of claim 1 , wherein the mean pore size of the interlayer is approximately 2 to 100 times larger than the mean pore size of the fiber containing first or second filter layers on either side of the interlayer.

15 . A fluid filtration device comprising:
holder having an inlet, a filtrate outlet, a retentate outlet, and the composite media of claim 1 , wherein the composite media is located in the holder and separates the holder into an upstream compartment and a downstream compartment.

16 . The fluid filtration device according to claim 15 is selected from the group consisting of a plastic holder, laboratory device, syringe, microtiter plate, metal holder, filter cartridge, and cartridge.

Assignees

• Emd Millipore Corp

Inventors

• Giglia Sal
• Nhiem David
• Ashby Leon Sherry
• Tkacik Gabriel

Classifications

• B01D39/1623 Primary

  of synthetic origin · CPC title

• B01D2239/065

  More than one layer present in the filtering material · CPC title

• B01D2239/025

  comprising nanofibres · CPC title

• B01D2239/0631

  Electro-spun · CPC title

• B01D2239/0618

  Non-woven · CPC title