SUPER ABSORBENT CONTAINING WEB THAT CAN ACT AS A FILTER, ABSORBENT, REACTIVE LAYER OR FUEL FUSE

• US 20090065436A1
• Filed: 03/13/2008
• Published: 03/12/2009
• Est. Priority Date: 03/15/2007
• Status: Active Grant

• Current Assignee: Donaldson Company Incorporated
• Original Assignee: Donaldson Company Incorporated
• Inventors: KALAYCI, VELI E., Doyle, James, Mehta, Ketan C., Babcock, Brian, Johnson, Philip Edward, Hebert, Mike J., Jones, Derek O.
• Granted Patent: US 7,988,860 B2
• Time in Patent Office: Days
• US Class Current: 210/679
• CPC Class Codes: B01D 2239/0216 Bicomponent or multicomponent fibres
• CPC Class Codes: B01D 2239/025 comprising nanofibres apparatus incorporating such gas filtering material see B01D46/546
• CPC Class Codes: B01D 2239/0407 comprising particulate additives, e.g. adsorbents apparatus incorporating gas filtering material B01D46/0036
• CPC Class Codes: B01D 2239/065 More than one layer present in the filtering material apparatus incorporating such gas filtering material B01D2275/10
• CPC Class Codes: B01D 39/1623 of synthetic origin
• CPC Class Codes: B01D 46/0036 by adsorption or absorption
• CPC Class Codes: B01D 46/546 using nano- or microfibres
• CPC Class Codes: Y10T 428/24975 No layer or component greater than 5 mils thick
• CPC Class Codes: Y10T 428/249921 Web or sheet containing structurally defined element or component
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 442/184 Nonwoven scrim
• CPC Class Codes: Y10T 442/659 Including an additional nonwoven fabric

Abstract

The web of the invention can comprise a super absorbent layer that can act as an moisture sensitive fuel shut-off valve, absorbent, adsorbant or reactant. The web of the invention can comprise a super absorbent fabric or layer made of a superabsorbent particle or fiber. The web can comprise a nanofiber layer having dispersed within the nanofiber layer a super absorbent particulate and optionally a second particulate material that can act as an absorbent, adsorbant or reactant. Fluid, gas or liquid, that flows through or by the assemblies of the invention can have any gas, liquid or solid material dispersed or dissolved in the fluid interact with the super absorbent particulate. If needed these materials can also react with, be absorbed by, or adsorbed onto, the active particulate within the nanofiber layer. The structures of the invention can act simply as flow-by reactive, absorptive, or adsorptive layers with no filtration properties, or the structures of the invention can be assembled into filters that can filter particulate from a mobile fluid in a flow-through mode while simultaneously reacting, absorbing, or adsorbing materials from the mobile fluid.

Claims

18. An element comprising a filter media, the media comprising a first and second opposite flow faces;

and a plurality of flutes;

(i) each of said flutes having a first open end portion adjacent to said first flow face and a second open end portion adjacent to said second flow face;

(ii) said media including a substrate at least partially covered by a web of nanofibers, said media comprising a super absorbent particle fiber or fabric.

1. A web comprising a substantially continuous nanofiber having a diameter of about 0.001 to 5 micron and an active particulate dispersed in the fiber layer or fiber web, the particulate comprising a super absorbent and comprising 0.1 to 50 vol % of the web, the web having a thickness of about 0.0001 to 1 cm and the super absorbent comprises about 0.001 to 10 kg per square meter of the layer or web.

2. The web of claim 1, wherein the solidity is about 1 to 50%.

3. The web of claim 1, wherein the web comprises a flow-by direction such that a fluid can flow in a path parallel to the web with no filtration path through the web.

4. The web of claim 1, wherein the nanofiber has a diameter of about 0.001 to 0.5 micron.

5. The web of claim 1, wherein the web comprises about 5 to 95 wt % fiber and about 95 to 5 wt % super absorbent particulate and the layer comprises 1 to 1000 grams of super absorbent particulate per square meter.

6. The web of claim 1, wherein the web comprises about 30 to 75 wt % fiber and about 70 to 25 wt % super absorbent particulate, the web comprising 1 to 1000 grams of super absorbent particulate per square meter

7. The web of claim 1, wherein the active particulate has a major dimension less than about 5000 microns.

8. The web of claim 1, wherein the web also comprises an active particulate comprising an absorbent particulate, an adsorbent particulate, a reactive particulate, or mixtures thereof.

9. The web of claim 1, wherein the super absorbent particulate has a major dimension of about 0.05 to 100 microns.

10. The web of claim 1, wherein the web has a Frazier permeability of about 1 to about 50 meters-minutes⁻

1 and an efficiency of about 40 to about 99.9999% under ASTM 1215-89 using monodispersed 0.78 micron polystyrene particulate at 6.1 m-min<sup>−

1</sup> or 20 ft-min<sup>−

1</sup>.

11. The web of claim 1, wherein the web comprises one or more layers of web each layer having a thickness of at least about 0.5 micron.

12. The web of claim 1, wherein the web at least a first layer comprising the super absorbent and at least a second layer comprising an active particulate.

13. The web of claim 1, wherein the second layer comprises an active particulate comprising a combination of an inert particulate and an active particulate spacer means.

14. The web of claim 1, wherein the web comprises the super absorbent and an active particulate.

15. The web of claim 1, wherein the web has a gradient in the distribution of the active particulate spacer means.

16. The web of claim 1, wherein the web has a gradient in the distribution of the super absorbent.

17. A filter media comprising a filtration substrate and the web of claims 1.

19. The element of claim 18, wherein a super absorbent particulate is dispersed in the nanofiber layer, the particulate comprising 0.1 to 50 vol % of the layer, the fiber having a diameter of about 0.001 to about 5 microns, and the layer having a thickness of 0.5 to 500 microns;

wherein the element comprises a flow-by or flow through path such that a fluid can flow in a path parallel to the substrate.

20. The element of claim 18, wherein selected ones of said flutes being open at said first end portion and closed at said second end portion;

and selected ones of said flutes being closed at said first end portion and open at said second end portion provides a fluid path through the fluted layer.

21. The element of claim 18, wherein the web comprises about 5 to 95 wt % nanofiber and about 95 to 5 wt % super absorbent fiber and the nanofiber has a diameter of about 0.001 to 0.5 micron.

22. The element of claim 18, wherein the web comprises about 30 to 75 wt % fiber and about 70 to 25 wt % super absorbent particulate.

23. The element of claim 18, wherein the super absorbent particulate has a major dimension of about 0.1 to 500 microns.

24. The element of claim 18, wherein the web has a Frazier permeability of about 1 to about 50 meters-minutes⁻

1 and an efficiency of about 40 to about 99.9999% under ASTM 1215-89 using monodispersed 0.78 micron polystyrene latex particulate at 6.1 m-min<sup>−

1</sup> or 20 ft-min<sup>−

1</sup>.

25. The element of claim 18, wherein the filter structure comprises one or more nanofiber webs having a thickness of at least about 0.5 micron, at least one layer comprises super absorbent particulate or fabric and at least one other layer comprises an active particulate.

26. The element of claim 18, wherein the particulate active is an absorbent.

27. The element of claim 18, wherein the particulate is an adsorbent.

28. The element of claim 18, wherein the particulate is a reactive particulate.

29. The element of claim 18, wherein the web has a gradient in the distribution of the super absorbent particulate or fiber.

30. The element of claim 18, wherein the web has a gradient in the distribution of the fiber.

20-1. The element of claim 18, wherein the nanofiber has a diameter of about 0.001 to 0.5 micron.

31. A filter element comprising a filtration substrate and a nanofiber web comprising a substantially continuous nanofiber layer, the web having a thickness of about 0.1 to 100 microns and a pore size of about 0.01 to 10 microns, and a super absorbent fabric layer or dispersed in the fine fiber, a super absorbent particulate or fiber comprising about 0.1 to 50 vol % of the web, the super absorbent fiber or particulate comprising about 0.001 to 10 kg per square meter of the membrane.

32. The element of claim 31, wherein the element comprises a flow-by direction such that the fluid can flow in a path parallel to the membrane with no substantial filtration path through the membrane.

33. The element of claim 31, wherein the element comprises a flow through direction such that the fluid can flow in a path across the membrane with a substantial filtration path through the membrane.

34. The element of claim 31, wherein the element comprises about 5 to 95 wt % nanofiber layer mass and about 95 to 5 wt % super absorbent fiber or particulate and the element comprising 1 to 100 g-m⁻

2 of particulate.

35. The element of claim 31, wherein the element comprises about 30 to 75 wt % of nanofiber layer mass and about 70 to 25 wt % super absorbent fiber or particulate and the element comprising 1 to 1000 g-m⁻

2 of particulate.

36. The element of claim 31, wherein the super absorbent particulate has a major dimension of less than 500 microns.

37. The element of claim 31, wherein the super absorbent particulate also comprises an absorbent particulate, and adsorbent particulate, a reactive particulate or mixtures thereof.

38. The element of claim 31, wherein the particulate has a major dimension of about 5 to 200 microns.

39. The element of claim 31, wherein the element comprises two or more layers, one layer comprising the web and a second layer, the second layer being substantially free of particulate.

40. The element of claim 31, wherein the second layer comprises a filter substrate.

41. A method for treating a fluid, the method comprising:

(a) directing fluid through a filter medium having first and second opposite flow faces; and

a plurality of flutes;

the medium comprising;

(i) each of the flutes having a first end portion adjacent to the first flow face and a second end portion adjacent to the second flow face;

(ii) selected ones of the flutes being open at the first end portion and closed at the second end portion; and

selected ones of the flutes being close at the first end portion and open at the second end portion;

(iii) the medium including a substrate at least partially covered by a layer of nanofibers; and

(iv) a layer comprising a super absorbent particulate, fiber or fabric;

wherein in the layer of superabsorbent, the superabsorbent comprises 0.1 to 50 vol % of the layer, the superabsorbent comprises a particulate or a fiber having a diameter of about 0.001 to about 5 microns, the layer having a thickness of 0.5 to 500 microns and a solidity of about 0.1 to 65%.

43. The method of claim 43 wherein the fluid comprises a hydrocarbon liquid.

42. The method of claim 43 wherein the fluid comprises a liquid.

44. The method of claim 43 wherein the fluid comprises a liquid vegetable oil.

45. The method of claim 43 wherein the fluid comprises liquid hydraulic oil.

46. The method of claim 43 wherein the liquid comprises a fuel

47. The method of claim 43 wherein the fluid comprises a gas

48. A method of removing moisture from an air stream, the method comprising contacting a moisture-laden air stream with a web, the web comprising a layer comprising a substantially continuous nanofiber layer, the nanofiber having a diameter of about 0.001 to about 5 microns and comprising a super absorbent fabric, fiber or particulate, the superabsorbent comprising 0.1 to 95 vol % of the layer, the layer having a thickness of about 0.0001 to 1 cm and the superabsorbent comprises about 0.001 to 10 kg-m² of the layer.

49. The method of claim 48, wherein the web is placed in a vent for an enclosure such that the interior of the enclosure is maintained at a substantially reduced moisture content with respect to the exterior of the enclosure.

50. The method of claim 48, wherein the enclosure comprises an enclosure containing an electronic circuit or device.

51. The method of claim 48, wherein the electronic circuit or device comprises a hard drive.

80. The method of claim 48 wherein the web absorbs water droplets and condensation from the moisture-laden air entering a gas turbine inlet.

81. The method of claim 48 wherein the web is placed in a vent for an enclosure or housing to absorb water droplets and condensation from moisture-laden air exiting the enclosure or housing.

52. A method of removing moisture from a hydrocarbon liquid, the method comprising contacting a moisture containing liquid with a web, the web comprising a layer comprising a substantially continuous nanofiber layer, the nanofiber having a diameter of about 0.001 to about 5 microns and comprising a super absorbent fabric, fiber or particulate, the superabsorbent comprising 0.1 to 50 vol % of the layer, the layer having a thickness of about 0.0001 to 1 cm and the superabsorbent comprises about 0.001 to 10 kg-m⁻

2 of the layer.

54. The method of claim 54 wherein the fuel comprises gasoline.

53. The method of claim 54 wherein the hydrocarbon liquid comprises a fuel.

55. The method of claim 54 wherein the fuel comprise diesel fuel.

56. The method of claim 54 wherein the hydrocarbon liquid comprises ethanol.

57. The method of claim 54 wherein the fuel comprises jet aviation fuel.

58. The method of claim 54 wherein the liquid comprises a lubricant.

59. The method of claim 54 wherein the lubricant comprises a grease.

60. The method of claim 54 wherein the lubricant comprises an oil.

61. The method of claim 54 wherein the lubricant comprises a cutting oil.

62. A method of removing moisture from an air stream transiting a vent in a disc drive, the method comprising contacting a moisture-laden air stream with a web, the web in the disc drive vent, the web comprising a layer comprising a substantially continuous nanofiber layer, the fiber having a diameter of about 0.001 to about 5 microns and comprising a super absorbent fiber or particulate in the nanofiber layer, the particulate comprising 0.1 to 50 vol % of the layer, the layer having a thickness of about 0.0001 to 1 cm and the active particulate comprises about 0.001 to 10 kg-m⁻

2 of the layer.

64. A web comprising a layered composite comprising:

(a) a substantially continuous nanofiber layer, the nanofiber having a fiber diameter of about 0.01 to 5 micron; and

(b) a superabsorbent fabric wherein the fabric comprises a layer having a thickness of greater than 100 microns.

63. The method of claim 64, wherein the web is placed in a vent for an drive enclosure such that the interior of the enclosure is maintained at a substantially reduced moisture content with respect to the exterior of the enclosure.

65. The web of claim 64 wherein nanofiber is formed on a scrim.

66. The web of claim 64 wherein the web comprises a filter layer.

67. The web of claim 66 wherein the filter layer can accumulate particulate having a particle size of about 1 to 100 microns.

68. The web of claim 64 wherein the layered composite comprises, in order:

(a) a substantially continuous nanofiber layer, the nanofiber having a fiber diameter of about 0.01 to 5 micron;

(b) a superabsorbent fabric wherein the fabric comprises a layer having a thickness of greater than 100 microns; and

(c) a substantially continuous nanofiber layer, the nanofiber having a fiber diameter of about 0.01 to 5 micron.

69. The web of claim 64 wherein the layered composite comprises, in order:

(a) a filter layer;

(b) a substantially continuous nanofiber layer, the nanofiber having a fiber diameter of about 0.01 to 5 micron;

(c) a superabsorbent fabric wherein the fabric comprises a layer having a thickness of greater than 100 microns;

(d) a substantially continuous nanofiber layer, the nanofiber having a fiber diameter of about 0.01 to 5 micron; and

(e) a filter layer;

70. The web of claim 69 wherein the filter layer comprises a bicomponent layer having a basis weight of about 10 to 100 g-m⁻

2 and a thickness of about 2 to 50 microns.

71. The web of claim 69 wherein the nanofiber layer comprises an efficiency of greater than about 95% with a 0.3 micron test particle at 10.5 ft-min⁻

1.

72. The web of claim 64 wherein the superabsorbent fabric comprises a layer comprising a basis weight of about 50 to 500 g-m⁻

2 and a thickness of about 0.2 to 40 mm.

73. A filter element comprising a core and at least one layer of the media of claim 64.

74. The element of claim 73 wherein the core comprises a perforate core or a screen support.

75. A hydrocarbon fuel fuse capable of stopping fuel flow in the presence of water contamination, the fuse comprising the element of claim 73.

76. A method of stopping fuel flow in the presence of water contamination, the method comprises:

(a) flowing fuel containing at least 10 ppm water, based on the fuel, in a stream from a source through a conduit into a fuel tank, the stream also passing through a fuse comprising the web of claim 64, and

(b) removing the conduit from the tank at such a time that the contaminated fuel flow is stopped by the action of the fuse.

77. A method of removing dissolved or dispersed water from a fuel, the method comprising:

(a) flowing fuel containing at least 10 ppm water, based on the fuel, in a stream from a source through a conduit into a fuel tank, the stream also passing through a filter element comprising the web of claim 64.

78. The fuel fuse of claim 75 wherein the fuse is capable of stopping fuel flow when the differential pressure across the fuse is from 1-50 psi.

79. The fuel fuse of claim 78 wherein the fuse is capable of stopping fuel flow without superabsorbent material migrating out of the fuse.