Bag house filter with fine fiber and spun bonded media

• US 7,318,852 B2
• Filed: 04/06/2006
• Issued: 01/15/2008
• Est. Priority Date: 09/05/2000
• Status: Expired due to Term

• Current Assignee: Donaldson Company Incorporated
• Original Assignee: Donaldson Company Incorporated
• Inventors: Chung, Hoo Y., Gogins, Mark A., Weik, Thomas M., Crofoot, Douglas G., Hall, John R. B.
• Primary Examiner(s): Smith; Duane
• Assistant Examiner(s): PHAM, MINH CHAU THI
• Application Number:
  US11/398,788
• Publication Number:
  US 20070271883A1
• Time in Patent Office: 649 Days
• Field of Search: 555/27, 555/28, 554/82, 554/86, 553/82, 428/36.1, 428/181, 428/212, 428/220, 428/903
• US Class Current: 55/527
• CPC Class Codes: B01D 2239/025 comprising nanofibres apparatus incorporating such gas filtering material see B01D46/546
• CPC Class Codes: B01D 2239/0428 Rendering the filter material hydrophobic
• CPC Class Codes: B01D 2239/0492 on fibres
• CPC Class Codes: B01D 2239/0613 Woven
• CPC Class Codes: B01D 2239/0618 Non-woven
• CPC Class Codes: B01D 2239/0627 Spun-bonded
• CPC Class Codes: B01D 2239/064 The fibres being mixed
• 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 2239/0654 Support layers
• CPC Class Codes: B01D 2239/1233 Fibre diameter
• CPC Class Codes: B01D 2239/1258 Permeability
• CPC Class Codes: B01D 2275/10 Multiple layers
• CPC Class Codes: B01D 39/04 Organic material, e.g. cellulose, cotton
• CPC Class Codes: B01D 39/086 of inorganic material
• CPC Class Codes: B01D 39/1623 of synthetic origin
• CPC Class Codes: B01D 39/163 sintered or bonded
• CPC Class Codes: B01D 39/18 the material being cellulose or derivatives thereof cork or peat B01D39/1646 ; making filter paper D21F11/14
• CPC Class Codes: B01D 46/0001 Making filtering elements
• CPC Class Codes: B01D 46/02 Particle separators, e.g. dust precipitators, having hollow filters made of flexible material
• CPC Class Codes: B01D 46/10 Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces
• CPC Class Codes: B01D 46/2411 : Filter cartridges
• CPC Class Codes: B01D 46/521 : using folded, pleated material
• CPC Class Codes: B01D 46/523 : with means for maintaining spacing between the pleats or folds
• CPC Class Codes: B01D 46/546 : using nano- or microfibres
• CPC Class Codes: C08L 65/00 : Compositions of macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain C08L7/00 - C08L57/00, C08L61/00 take precedence; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 77/00 : Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain of polyhydrazides C08L79/06; of polyamideimides or polyamide acids C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: D01D 5/0007 : Electro-spinning non-woven fabrics produced by electro-spinning D04H1/728
• CPC Class Codes: D01D 5/003 : the material being a polymer solution or dispersion D01D5/0053 takes precedence
• CPC Class Codes: D01D 5/0084 : Coating by electro-spinning, i.e. the electro-spun fibres are not removed from the collecting device but remain integral with it, e.g. coating of prostheses
• CPC Class Codes: D01F 1/10 : Other agents for modifying properties
• CPC Class Codes: D01F 6/80 : from copolyamides
• CPC Class Codes: D01F 6/90 : of polyamides
• CPC Class Codes: D01F 6/92 : of polyesters
• CPC Class Codes: D04H 3/02 : characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments
• CPC Class Codes: Y10S 428/903 : Microfiber, less than 100 micron diameter
• CPC Class Codes: Y10T 428/1362 : Textile, fabric, cloth, or pile containing [e.g., web, net, woven, knitted, mesh, nonwoven, matted, etc.]
• CPC Class Codes: Y10T 428/24686 : Pleats or otherwise parallel adjacent folds
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree
• 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 428/29 : Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
• CPC Class Codes: Y10T 428/2915 : including textile, cloth or fabric
• CPC Class Codes: Y10T 428/2933 : Coated or with bond, impregnation or core
• CPC Class Codes: Y10T 428/2938 : Coating on discrete and individual rods, strands or filaments
• CPC Class Codes: Y10T 428/2967 : Synthetic resin or polymer
• CPC Class Codes: Y10T 428/2969 : Polyamide, polyimide or polyester
• CPC Class Codes: Y10T 428/298 : Physical dimension
• CPC Class Codes: Y10T 442/16 : Two or more nonwoven layers
• CPC Class Codes: Y10T 442/614 : Strand or fiber material specified as having microdimensions [i.e., microfiber]
• CPC Class Codes: Y10T 442/626 : Microfiber is synthetic polymer
• CPC Class Codes: Y10T 442/659 : Including an additional nonwoven fabric

Abstract

Disclosed are improved polymer materials. Also disclosed are fine fiber materials that can be made from the improved polymeric materials in the form of microfiber and nanofiber structures. The microfiber and nanofiber structures can be used in a variety of useful applications including the formation of filter materials.

Claims

1. A filter bag for an industrial bag house, the bag comprising:

(a) a layer of a polyester filter bag substrate having a thickness greater than about 0.2 mm, a layer of fine fiber on the upstream surface of the substrate, the fine fiber layer having a fiber diameter of about 0.01 to 5 micron and a basis weight of about 0.0005 to 0.2 mg-cm<sup>−

2</sup>, said fine fiber layer having a thickness of about 1 to 100 times the diameter of the fine fiber, the polyester filter bag substrate layer having a permeability of at least 2 m-min<sup>−

1</sup> and an efficiency of at least 20% when measured according to ASTM-1215-89, with 0.78 micron monodisperse polystyrene spherical particles, at 20 fpm (6.1 meters/min).

2. The bag of claim 1 wherein the fine fiber is covered with a protective layer.

3. The bag of claim 1 wherein the fine fiber diameter is about 0.01 to 2 microns.

4. The bag of claim 1 wherein the fine fiber diameter is about 0.01 to 0.5 micron.

5. The bag of claim 1 wherein the layer is a multilayer of fine fiber.

6. The bag of claim 1 wherein the substrate comprises a spun bonded fabric.

7. The bag of claim 1 wherein the substrate comprises a non-woven fabric.

8. The bag of claim 1 wherein the substrate comprises a woven fabric.

9. The bag of claim 1 wherein the fine fiber comprises a polymer that comprises an addition polymer and an additive that forms a coating on the fiber.

10. The bag of claim 1 wherein the fine fiber comprises a polymer that comprises an condensation polymer and an additive that forms a coating on the fiber.

11. The bag of claim 1 wherein the fine fiber comprises a reaction product of a condensation polymer and a crosslinking agent, the fine fiber having a fiber diameter of about 0.01 to 0.5 micron.

12. The bag of claim 1 wherein the fine fiber, when exposed to an air stream having a temperature of about 140°

F. and a relative humidity of about 100%, greater than about 50% of the fiber survives for more than 1-16 hours.

13. The bag of claim 1 wherein the fine fiber comprises a reaction product of a addition polymer and a crosslinking agent, the fiber having a fiber diameter of about 0.01 to 0.5 micron.

14. The bag of claim 1 wherein the fine fiber, when exposed to an air stream having a temperature of about 140°

F. and a relative humidity of about 100%, greater than about 50% of the fiber survives for more than 1-16 hours.

15. The bag of claim 9 wherein the fine fiber comprises polymer that comprises a nylon and the additive forms a coating on the fiber with hydrophobic properties.

16. The bag of claim 1 wherein the polyester filter bag substrate comprises polyethylene terephthalate.

17. The bag of claim 1 wherein the fine fiber comprises a polyvinyl alcohol.

18. The bag of claim 17 wherein the fiber comprises a reaction product of a polyvinyl alcohol and a crosslinking agent, the crosslinking agent present in an amount of about 5 to 50 wt % based on the polyvinyl alcohol polymer.

19. The bag of claim 1, wherein the fine fiber comprises a polyurethane polymer.

20. The bag of claim 1, wherein the fine fiber comprises a reaction product of a polyurethane polymer and a crosslinking agent.

50. The filter of claim 1 wherein the fine fiber comprises a reaction product of a condensation polymer and a cross-linking agent, the fine fiber having a fiber diameter of about 0.01 to 0.5 micron.

51. The filter of claim 1 wherein the fine fiber, when exposed to an air stream having a temperature of about 140°

F. and a relative humidity of about 100%, greater than about 50% of the fiber survives for more than 16 hours.

52. The filter of claim 1 wherein the fine fiber comprises a reaction product of a addition polymer and a crosslinking agent, the fiber having a fiber diameter of about 0.01 to 0.5 micron.

53. The filter of claim 1 wherein the polyester substrate comprises polyethylene terephthalate.

54. The filter of claim 1 wherein the fine fiber comprises a polyvinyl alcohol.

55. The filter of claim 17 wherein the fiber comprises a reaction product of a polyvinyl alcohol and a cross-linking agent, the cross-linking agent present in an amount of about 5 to 50 wt % based on the polyvinyl alcohol polymer.

56. The filter of claim 1, wherein the fine fiber comprises a polyurethane polymer.

57. The filter of claim 1, wherein the fine fiber comprises a reaction product of a polyurethane polymer and a cross-linking agent.

21. A bag house filter assembly comprising a filter structure that can pass a gaseous medium;

the assembly comprising a plurality of flexible filter bags, each bag configured for treating industrial effluent or off-gas, each bag comprising a polyester filter substrate having a thickness greater than 0.4 mm comprising an elongated filter surface, the structure ensuring that the gaseous medium passes through the flexible filter bag within the structure;

a support associated with each said flexible bag;

wherein polyester filter substrate of each flexible bag is at least partially covered by a fine fiber layer having a basis weight of 0.0005 to 0.2 mg-cm<sup>−

2</sup> and a thickness of 0.1 to 3 microns comprising a polymeric fine fiber with a diameter of about 0.01 to about 5 microns and the filter has a permeability of at least 2 m-min<sup>−

1</sup> and an efficiency of at least 20% when measured according to ASTM-1215-89, with 0.78 micron monodisperse polystyrene spherical particles, at 20 fpm (6.1 meters/min).

22. The bag house of claim 21 wherein the fine fiber is covered with a protective layer.

23. The bag house of claim 21 wherein the fine fiber layer is a multilayer of fine fiber.

24. The bag house of claim 21 wherein the fine fiber diameter is about 0.001 to about 2 microns and the thickness of the layer is about 1 to 100 times the diameter of the fine fiber.

25. The bag house of claim 21 wherein the fiber diameter of the fine fiber layer is about 0.01 to 0.5 micron.

26. The bag house of claim 21 wherein the polyester filter substrate of the bag comprises a spun bonded fabric.

27. The bag house of claim 21 wherein the polyester filter substrate of the bag comprises a non-woven fabric.

28. The assembly of claim 21 wherein the polyester filter substrate of the bag comprises a woven fabric.

29. The bag house of claim 21 wherein the fine fiber comprises an addition polymer.

30. The bag house of claim 21 wherein the fine fiber comprises an condensation polymer.

31. The bag house of claim 21 wherein the fine fiber comprises an addition polymer and an additive that forms a coating on the fiber.

32. The bag house of claim 21 wherein the fine fiber comprises an condensation polymer and an additive that forms a coating on the fiber.

33. The bag house of claim 21 wherein the polyester filter substrate comprises polyethylene terephthalate.

34. The bag house of claim 29 wherein the polymeric fine fiber comprises the reaction product of a condensation polymer and a crosslinking agent, the fiber having a fiber size of about 0.01 to 0.5 micron wherein the fiber, when exposed to an air stream having a temperature of about 140°

F. and a relative humidity of about 100%, greater than about 50% of the fiber survives for more than 1-16 hours.

35. The bag house of claim 30 wherein the polymeric fine fiber comprises the reaction product of a addition polymer and a crosslinking agent, the fine fiber having a fiber diameter of about 0.01 to 0.5 micron wherein the fine fiber, when exposed to an air stream having a temperature of about 140°

F. and a relative humidity of about 100%, greater than about 50% of the fiber survives for more than 1-16 hours.

36. The bag house of claim 21 wherein the fine fiber comprises a polyurethane polymer.

37. The bag house of claim 34, the fine fiber comprising a reaction product of a polyurethane polymer and a crosslinking agent.

38. The bag house of claim 35 wherein the polymeric fine fiber comprises a nylon and an additive that forms a coating on the fiber with hydrophobic properties.

39. The bag house of claim 38 wherein the additive is hydrophobic.

40. The bag house of claim 38 wherein the additive is hydrophobic.

41. The bag house of claim 35 wherein the polymeric fine fiber comprises polyvinyl alcohol crosslinked with about 1 to 40 wt % of a crosslinking agent.

42. The assembly of claim 21 wherein the filter structure comprises a layer of fine fiber on an upstream surface of the filter and a second layer of fine fiber on an exit surface of the filter.

43. The assembly of claim 21 wherein the filter structure comprises a layer of fine fiber on an exit surface of the filter.

44. A filter for industrial dust collection, the filter comprising:

a layer of a polyester filter substrate having a thickness greater than about 0.2 mm, a layer of fine fiber on the upstream surface of the substrate, the fine fiber layer having a fiber diameter of about 0.01 to 5 micron and a basis weight of about 0.0005 to 0.2 mg-cm<sup>−

2</sup>, said fine fiber layer having a thickness of about 1 to 100 times the diameter of the fine fiber, the polyester filter substrate layer having a permeability of at least 2 m-min<sup>−

1</sup> and an efficiency of at least 20% when measured according to ASTM-1215-89, with 0.78 micron monodisperse polystyrene spherical particles, at 20 fpm (6.1 meters/min).

45. The filter of claim 44 wherein the fine fiber diameter is about 0.01 to 2 microns.

46. The filter of claim 44 wherein the fine fiber diameter is about 0.01 to 0.5 micron.

47. The filter of claim 44 wherein the filter comprises a cartridge filter with at least one open end and at least one flexible seal.

48. The filter of claim 47 wherein the substrate comprises a pleated substrate.

49. The filter of claim 44 wherein the substrate comprises a non-woven fabric.

58. An industrial dust collection filter assembly comprising a filter structure that can pass a gaseous medium;

the assembly comprising a plurality of filters, each filter configured for treating industrial effluent or off-gas, each filter comprising a pleated polyester filter substrate having a thickness greater than 0.4 mm comprising an elongated filter surface, the structure ensuring that the gaseous medium passes through the filter within the structure;

wherein polyester filter substrate is at least partially covered by a fine fiber layer having a basis weight of 0.0005 to 0.2 mg-cm<sup>−

2</sup> and a thickness of 0.1 to 3 microns comprising a polymeric fine fiber with a diameter of about 0.01 to about 5 microns and the filter has a permeability of at least 2 m-min<sup>−

1</sup> and an efficiency of at least 20% when measured according to ASTM-1215-89, with 0.78 micron monodisperse polystyrene spherical particles, at 20 fpm (6.1 meters/min).

59. The filter of claim 58 wherein the filter comprises a cartridge with at least one open end and at least one flexible seal.