Filter media suitable for hydraulic applications

Patent metadata

Field	Value
Publication number	US-9950284-B2
Application number	US-201414584155-A
Country	US
Kind code	B2
Filing date	Dec 29, 2014
Priority date	Apr 3, 2009
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

Filter media, including those suitable for hydraulic applications, and related components, systems, and methods associated therewith are provided. The filter media described herein may include two or more layers, at least one of the layers having a relatively high percentage of microglass fibers. Additionally, the filter media may be designed such that the ratio of average fiber diameters between two layers is relatively small, which can lead to a relatively low resistance ratio between the layers. In some embodiments, at least one layer of the filter media comprises synthetic polymer fibers. Certain filter media described herein may have desirable properties including high dirt holding capacity and a low resistance to fluid flow. The media may be incorporated into a variety of filter element products including hydraulic filters.

First claim

What is claimed is:

1. A filter media comprising:
a first layer comprising fibers, wherein the fibers in the first layer comprise synthetic polymer fibers, and wherein the fibers in the first layer have a first average diameter;
a second layer adjacent to the first layer, the second layer comprising fibers, wherein the fibers in the second layer comprise synthetic polymer fibers, wherein the fibers in the second layer have a second average diameter, and wherein the first average diameter is greater than the second average diameter; and
a third layer adjacent to the second layer, the third layer comprising fibers, wherein the fibers in the third layer comprise synthetic polymer fibers, wherein the fibers in the third layer have a third average diameter, wherein the second average diameter is greater than the third average diameter, wherein the third layer has a thickness of less than about 500 microns, wherein the third layer has a mean flow pore size of between about 5 microns and about 50 microns, and wherein the third layer has an air permeability of between about 50 cfm/sf and about 250 cfm/sf as measured by TAPPI Method T251;
wherein the filter media has a thickness of between about 5 mils and about 300 mils, an overall basis weight of between about 20 and 200 gsm as measured by TAPPI Standard T410, and an overall air permeability of between about 7 cfm/sf and about 200 cfm/sf as measured by TAPPI Method T251,
wherein the filter media has an efficiency of at least 99.5% for 25 micron or larger particles as measured by a Multipass Filter Test, and
wherein the Multipass Filter Test is a measurement performed in accordance with a procedure described in ISO 16889 using a hydraulic test fluid, a dust level of 10 mg/liter, and a face velocity of 0.14 meters/min, and performed until a terminal pressure of 172 kPa above a baseline filter pressure drop is obtained,
wherein at least one layer comprises at least about 97 wt. % synthetic fibers.

2. The filter media of claim 1 , wherein the first layer has an air permeability of from about 4 cfm/sf to about 400 cfm/sf as measured by TAPPI Method T251.

3. The filter media of claim 1 , wherein the first layer has a basis weight of between about 10 gsm and about 100 gsm as measured by TAPPI Standard T410.

4. The filter media of claim 1 , wherein the first layer has a thickness of between about 3 mils and about 40 mils.

5. The filter media of claim 1 , wherein the first average diameter is between about 1.0 micron and about 10.0 microns.

6. The filter media of claim 1 , wherein the second layer has an air permeability of from about 15 cfm/sf to about 150 cfm/sf as measured by TAPPI Method T251.

7. The filter media of claim 1 , wherein the second layer has a basis weight of between about 10 gsm and about 100 gsm as measured by TAPPI Standard T410.

8. The filter media of claim 1 , wherein the second layer has a thickness of between about 3 mils and about 40 mils.

9. The filter media of claim 1 , wherein the second average diameter is between about 1.0 micron and about 9.0 microns.

10. The filter media of claim 1 , wherein a normalized resistance ratio of the second layer to the first layer is between 1:1 and 6:1, and wherein the normalized resistance ratio is a ratio of a resistance of the second layer as measured by TAPPI Method T251, divided by a basis weight of the second layer as measured by TAPPI Standard T410, to a resistance of the first layer as measured by TAPPI Method T251, divided by a basis weight of the first layer as measured by TAPPI Standard T410.

11. The filter media of claim 1 , wherein a ratio of basis weights as measured by TAPPI Standard T410 between the second layer and the first layer is less than 2:1.

12. The filter media of claim 1 , wherein the third layer has a basis weight of at least about 1 gsm and less than about 75 gsm as measured by TAPPI Standard T410.

13. The filter media of claim 1 , wherein the thickness of the third layer is at least about 30 microns and less than about 500 microns.

14. The filter media of claim 1 , wherein the third average diameter is between about 0.8 microns and about 5.0 microns.

15. The filter media of claim 1 , wherein the mean flow pore size of the third layer is between about 13 microns and about 50 microns.

16. The filter media of claim 1 , wherein a normalized resistance ratio of the third layer to the first layer is between 1:1 and 8:1, and wherein the normalized resistance ratio is a ratio of a resistance of the second layer as measured by TAPPI Method T251, divided by a basis weight of the second layer as measured by TAPPI Standard T410, to a resistance of the first layer as measured by TAPPI Method T251, divided by a basis weight of the first layer as measured by TAPPI Standard T410.

17. The filter media of claim 1 , wherein a ratio of basis weights as measured by TAPPI Standard T410 between the first layer and the third layer, or between the second layer and the third layer, is greater than 1:1.

18. The filter media of claim 1 , wherein the third layer comprises polyester or polyamide fibers.

19. The filter media of claim 1 , wherein the fibers in the third layer have an average length of at least about 1 inch.

20. The filter media of claim 1 , comprising a fourth layer, wherein the fourth layer has an average fiber diameter smaller than the third average diameter, and wherein the fourth layer is adjacent one or more of the first layer, the second layer, and the third layer.

21. The filter media of claim 20 , wherein the fourth layer has a basis weight of less than about 50 gsm as measured by TAPPI Standard T410.

22. The filter media of claim 20 , wherein the fourth layer has a thickness of at least about 30 microns and less than about 500 microns.

23. The filter media of claim 20 , wherein the fourth layer has an air permeability of from about 15 cfm/sf to about 150 cfm/sf as measured by TAPPI Method T251.

24. The filter media of claim 1 , wherein the first layer has an air permeability of from about 4 cfm/sf to about 400 cfm/sf as measured by TAPPI Method T251 and a basis weight of between about 10 gsm and about 100 gsm as measured by TAPPI Standard T410, wherein the first average diameter is between about 1.0 micron and about 10.0 microns, wherein the second layer has an air permeability of from about 15 cfm/sf to about 150 cfm/sf as measured by TAPPI Method T251 and a basis weight of between about 10 gsm and about 100 gsm as measured by TAPPI Standard T410, and wherein the second average diameter is between about 1.0 micron and about 9.0 microns.

25. The filter media of claim 24 , wherein the third layer has a basis weight of at least about 1 gsm and less than about 75 gsm as measured by TAPPI Standard T410, wherein the mean flow pore size of the third layer is between about 13 microns and about 50 microns, and wherein the third average diameter is between about 0.8 microns and about 5.0 microns.

26. The filter media of claim 25 , comprising a fourth layer, wherein the fourth layer has an air permeability of from about 15 cfm/sf to about 150 cfm/sf as measured by TAPPI Method T251, a basis weight of less than about 50 gsm as measured by TAPPI Standard T410, wherein the fourth layer has an average fiber diameter smaller than the third average diameter, and wherein the fourth layer is adjacent one or more of the first layer, the second layer, and the third layer.

27. The filter

Assignees

• Hollingsworth & Vose Co

Inventors

• Thomson Cameron
• Godsay Milind
• Keisler Randall

Classifications

• B01D2239/1233

  Fibre diameter · CPC title

• B01D39/06

  Inorganic material, e.g. asbestos fibres, glass beads or fibres · CPC title

• B01D39/1623 Primary

  of synthetic origin · CPC title

• Y10T428/249969

  Of silicon-containing material [e.g., glass, etc.] · CPC title

• B01D2239/065

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