Filtration arrangement utilizing pleated construction and method

• US 6,800,117 B2
• Filed: 05/31/2001
• Issued: 10/05/2004
• Est. Priority Date: 09/05/2000
• Status: Expired due to Term

• Current Assignee: Donaldson Company Incorporated
• Original Assignee: Donaldson Company Incorporated
• Inventors: Barris, Marty A., Gogins, Mark A., Weik, Thomas M.
• Primary Examiner(s): Smith, Duane
• Assistant Examiner(s): Greene, Jason M.
• Application Number:
  US09/871,582
• Publication Number:
  US 20020073667A1
• Time in Patent Office: 1,223 Days
• Field of Search: 553/853, 554/82, 554/86, 554/87, 554/95, 554/98, 555/02, 555/27, 555/28, 553/851, 555/10, 555/21, 442/36, 952/73
• US Class Current: 95/273
• CPC Class Codes: B01D 2239/025 comprising nanofibres
• CPC Class Codes: B01D 2239/0654 Support layers
• CPC Class Codes: B01D 2239/10 Filtering material manufacturing
• CPC Class Codes: B01D 2239/1233 Fibre diameter
• CPC Class Codes: B01D 2271/027 Radial sealings
• CPC Class Codes: B01D 2279/60 for the intake of internal combustion engines or turbines
• CPC Class Codes: B01D 39/1623 of synthetic origin
• CPC Class Codes: B01D 46/0001 Making filtering elements
• CPC Class Codes: B01D 46/0005 Mounting of filtering elements within casings, housings or frames B01D46/2422 takes precedence
• CPC Class Codes: B01D 46/121 V-type arrangements
• CPC Class Codes: B01D 46/2411 Filter cartridges
• CPC Class Codes: B01D 46/521 using folded, pleated material
• CPC Class Codes: B01D 46/546 using nano- or microfibres
• CPC Class Codes: B01D 46/71 with pressurised gas, e.g. pulsed air
• CPC Class Codes: D01F 6/90 of polyamides
• CPC Class Codes: D01F 6/92 of polyesters
• CPC Class Codes: D04H 1/728 by electro-spinning electro-spinning methods and apparatus D01D5/0007
• CPC Class Codes: Y02A 50/2351 Atmospheric particulate matter [PM], e.g. carbon smoke microparticles, smog, aerosol particles, dust

Abstract

Filter arrangements include a barrier media, usually pleated, treated with a deposit of fine fibers. The media is particularly advantageous at high temperature (greater than 140° F.) systems. Such systems may include engine systems and fluid compressor systems. Filter arrangements may take the form of tubular, radially sealing elements; tubular, axial sealing elements; forward flow air cleaners; reverse flow air cleaners; and panel filters.

Claims

1. A system including an engine rated at an engine intake air flow of at least 3 cfm and having an air cleaner constructed and arranged to filter the engine intake air;

the air cleaner including a housing and a primary filter element operably positioned therein, the primary filter element comprising;

(a) a media pack comprising a sheet-like substrate, said pack having a first end and an opposite second end;

(i) said substrate having a plurality of pleats having a length extending from said first end to said second end, the substrate comprising a filter medium having an efficiency whom tested with particles having a diameter of 0.01 to 1 μ

m; and

(ii) said substrate at least partially covered by a single layer;

(A) said layer comprising a fine fiber having a diameter of about 0.01 to 0.5 microns such that after test exposure for a test period of 16 hours to test conditions of 140°

F. air and a relative humidity of 100% retains greater than 30% of the fiber unchanged for filtration purposes, said fiber comprising a polymer composition selected from the group consisting of;

(1) an addition polymer and about 2 to 25 wt % of an additive, the additive comprising a resinous material having a molecular weight of about 500 to 3000 and an aromatic character, the additive being miscible in the polymer but forms a hydrophobic coating on the fiber,

(2) a condensation polymer and about 2 to 25 wt % of an additive, the additive comprising a resinous material having a molecular weight of about 500 to 3000, and an aromatic character wherein the additive is miscible in the condensation polymer but forms a hydrophobic coating on the fiber, and

(3) mixtures thereof.

2. A filter element according to claim 1 wherein said seal is a radially directed seal.

3. A filter element according to claim 1 further including:

(a) an inner support liner extending between said first and second end caps;

(i) said inner support liner being between said scaling portion and said media pack.

4. A filter element according to claim 3 wherein:

(a) at least one of said first and second end caps includes an outer radial surface;

(i) said sealing portion comprising said outer radial surface.

5. A filter element according to claim 4 further including:

(a) an inner support liner extending between said first and second end caps;

(b) an outer support liner extending between said first and second and caps; and

wherein

(i) each of said plurality of pleats has a pleat length of at least 6 inches and a pleat depth of at least 1 inch.

6. The system of claim 1 wherein the polymer is a component of a solution, the solution comprising a major proportion of an aqueous alcoholic solvent and about 3 to 30 wt % of the polymeric composition based on the solution and the fiber retains a trace amount of solvent.

7. The system of claim 1 wherein the addition polymer comprises a polyvinyl halide polymer, a polyvinylidene halide polymer or mixtures thereof.

8. The system of claim 1 wherein the condensation polymer comprises a nylon polymer comprising a homopolymer having repenting units derived from a cyclic lactam.

9. The system of claim 1 wherein the condensation polymer comprises a nylon copolymer combined with a second nylon polymer, the second nylon polymer differing in molecular weight or monomer composition.

10. The system of claim 1 wherein the polymer comprises a polyvinylalcohol.

11. The system of claim 10 wherein the polyvinylalcohol is crosslinked with about 1 to 40 wt. % of a crosslinking agent.

12. The system of claim 8 wherein the nylon polymer is combined with a second nylon polymer, the second nylon polymer comprising an alkoxy alkyl modified polyamide.

13. The system of claim 12 wherein the polymers are treated to form a single polymeric composition as measured by a differential scanning calorimeter showing a single phase material.

14. The system of claim 1 wherein the polymer comprises a polyvinylchloride.

15. The system of claim 14 wherein the polyvinylchloride is crosslinked.

16. The system of claim 1 wherein the additive comprises an oligomer comprising tertiary butyl phenol.

17. The system of claim 16 wherein the additive comprises an oligomer comprising:

18. The system of claim 1 wherein the additive comprises an oligomer comprising bis-phenol A.

19. The system of claim 18 wherein the additive comprises:

20. The system of claim 1 wherein the additive comprises an oligomer comprising dihydroxy substituted biphenyl.

21. The system of claim 20 wherein the additive comprises:

22. The system of claim 7 wherein the polyvinylidene halide comprises polyvinylidene chloride.

23. The system of claim 7 wherein the polyvinylidene halide comprises polyvinylidene fluoride.

24. The system of claim 11 wherein the crosslinked polyvinylalcohol is crosslinked using a polyacrylic acid having a molecular weight of about 1000 to 3000.

25. The system of claim 11 wherein the crosslinked polyvinylalcohol is crosslinked using a melamine-formaldehyde resin having a molecular weight of about 1000 to 3000.

26. A system according to claim 1 wherein:

(a) the system includes an engine rated at an engine intake air flow of at least 100 cfm; and

(b) the primary element has a size and construction providing far an initial restriction of no greater than 3 inches of H₂O, when evaluated at air flow rates of up to 600 cfm.

27. A system according to claim 26 wherein:

(a) said pleated construction has a tubular shape and defines an open interior;

(b) said air cleaner housing includes an airflow tube;

said primary filter element being operably mounted on said airflow tube;

(c) said primary filter element father includes;

(i) a first, open end cap and a second, opposite end cap;

(A) said media pack being bonded to said first end cap at said first end of said media pack;

(B) said media pack being bonded to said second end cap at said second end of said media pack;

(ii) an inner support liner extending between said first and cap and said second end cap;

(iii) said first end cap including a radially or axially directed scaling portion;

(A) said scaling portion being inwardly directed toward said open interior;

(B) said scaling portion comprising a polyurethane foam material compressed between and against said inner support liner and said airflow tube to form a first radial seal between said primary filter element and said air cleaner housing.

28. A system according to claim 27 wherein:

(a) said primary filter element further includes an outer support liner extending between said first and second end caps;

(b) said second end cap defines a center aperture; and

(c) said second end cap includes a sealing portion;

(i) said scaling portion comprising a polyurethane foam material compressed between and against said outer support liner and said air cleaner to form a second radial seal between said primary filter element and said air cleaner housing.

29. A system according to claim 26 further including:

(a) a safety element operably installed in said air cleaner housing;

said safety element including;

(i) a pleated construction of a media composite;

said safety element pleated construction including a plurality of pleats;

(ii) said safety element pleated construction having a tubular shape and defining on open interior;

(iii) a safety element first end cap and a safety element second end cap;

said safety element pleated construction being bonded to and extending between said safety element first and second end caps;

(A) said safety element first end cap being ring-shaped defining an opening;

(B) said safety element second end cap being closed; and

(iv) said safety element first end cap including an outwardly radially directed sealing portion;

said outwardly radially directed sealing portion comprising a polyurethane material compressible to form a radial seal between said safety element and said air cleaner housing airflow tube.

30. A system according to claim 26 wherein:

(a) said pleated construction has a tubular shape and defines an open interior;

(b) said air cleaner housing includes a yoke arrangement to secure said housing to said primary filter element;

(c) said primary filter element further includes;

(i) a first, open end cap and a second, opposite closed end cap;

(A) said media pack being bonded to said first end cap at said first end of said media pack;

(B) said media pack being bonded to said second end cap at said second end of said media pack;

(C) said first end cap including an axially directed sealing potion;

(d) said axially directed sealing portion being pressed against said air cleaner housing by said yoke arrangement to form an axial seal between said primary filter element and said air cleaner housing.

31. A system according to claim 26 wherein:

(a) said primary filter element includes first and second opposite end caps bonded to said pleated construction;

(i) sad first end cap defining a plurality of air inlet apertures and an outlet tube;

(A) said outlet tube being secured to an air intake conduit of said engine;

(ii) said pleated construction being tubular in shape defining an open interior;

(iii) said second end cap being closed; and

(iv) said air cleaner housing being non-removably secured to said first and second end caps.

32. A system according to claim 26 wherein:

(a) said primary filter element comprises;

(i) a panel filter construction having an outer perimeter;

(ii) at least 40 pleats;

each of said pleats having a pleat depth of at least 2 inches;

(iii) an area within said outer perimeter of at least 35 square inches; and

(iv) an outer gasket member along said outer perimeter comprising a polymeric material.

49. The system of claim 18 wherein the additive comprises:

33. A system including a fluid compressor and having an air cleaner constructed and arranged to filter compressor intake air;

the air cleaner including a housing and a primary filter element operably positioned therein, the primary filter element comprising;

(a) a media pack baying a first end and an opposite second end;

(i) said media pack including a pleated construction of a media composite;

said pleated construction including a plurality of pleats having a length extending from said first and to said second end, the substrate comprising a filter medium having an efficiency when tested with particles having a diameter of 0.01 to 1 μ

m; and

(ii) said media composite including a substrate at least partially covered by a single layer;

(A) said layer comprising a fine fiber having a diameter of about 0.01 to 0.5 microns such that after test exposure for a test period of 16 hours to test conditions of 140°

F. air and a relative humidity of 100% retains greater than 30% of the fiber unchanged for filtration purposes, said fiber comprising a polymeric composition selected from the group consisting of;

(1) an addition polymer and about 2 to 25 wt % of an additive, the additive comprising a resinous material having a molecular weight of about 500 to 3000 and an aromatic character, the additive being but forms a hydrophobic coating on the fiber miscible in the polymer,

(2) a condensation polymer and about 2 to 25 wt % of an additive, the additive comprising a resinous material having a molecular weight of about 500 to 3000, and an aromatic character wherein the additive is miscible in the condensation polymer but forms a hydrophobic coating on the fiber, and

(3) mixtures thereof.

34. The system of claim 33 wherein the polymer is a component of a solution, the solution comprising a major proportion of an aqueous alcoholic solvent and about 3 to 30 wt % of the polymeric composition based on the solution and the fiber retains a trace amount of solvent.

35. The system of claim 33 wherein the addition polymer comprises a polyvinyl halide polymer, a polyvinylidene halide polymer or mixtures thereof.

36. The system of claim 33 wherein the condensation polymer comprises a nylon polymer comprising a homopolymer having repeating units derived from a cyclic lactam.

37. The system of claim 33 wherein the condensation polymer comprises a nylon copolymer combined with a second nylon polymer, the second nylon polymer differing in molecular weight or monomer composition.

38. The system of claim 33 wherein the polymer comprises a polyvinylalcohol.

39. The system of claim 38 wherein the polyvinylalcohol is crosslinked with bout 1 to 40 wt. % of a crosslinking agent.

40. The system of claim 36 wherein the nylon polymer is combined with a second nylon polymer, the second nylon polymer comprising an alkoxy alkyl modified polyamide.

41. The system of claim 40 wherein the polymers are treated to form a single polymeric composition as measured by a differential scanning calorimeter showing a single phase material.

42. The system of claim 33 wherein the polymer comprises a polyvinylchloride.

43. The system of claim 42 wherein the polyvinylchloride is crosslinked.

44. The system of claim 33 wherein the additive comprises an oligomer comprising tertiary butyl phenol.

45. The system of claim 44 wherein the additive comprises an oligomer comprising:

46. The system of claim 33 wherein the additive comprises an oligomer comprising bis-phenol A.

47. The system of claim 46 wherein the additive comprises:

48. The system of claim 37 wherein the additive comprises an oligomer comprising dihydroxy substituted biphenyl.

50. The system of claim 33 wherein the polymer is a component of a solution, the solution comprising a major proportion of an aqueous alcoholic solvent and about 3 to 30 wt % of the polymeric composition based on the solution.

51. The system of claim 35 wherein the polyvinylidene halide comprises polyvinylidene chloride.

52. The system of claim 35 wherein the polyvinylidene halide comprises polyvinylidene fluoride.

53. The system of claim 39 wherein the crosslinked polyvinylalcohol is crosslinked using a polyacrylic acid having a molecular weight of about 1000 to 3000.

54. The system of claim 39 wherein the crosslinked polyvinylalcohol is crosslinked using a melamine-formaldehyde resin having a molecular weight of about 1000 to 3000.

55. A system according to claim 33 wherein:

(a) the system includes an engine rated at an engine intake sir flow of at least 500 cfm; and

(b) the primary element has a size and construction providing for an initial restriction of no greater than 3 inches of H₂O, when evaluated at air flow rates of tip to 600 cfm.

56. A system according to claim 55 wherein:

(a) said pleated construction has a tubular shape and defines an open interior;

(b) said air cleaner housing includes an airflow tube;

said primary filter element being operably mounted on said airflow tube;

(c) said primary filter element further includes;

(i) a first, open end cap and a second, opposite end cap;

(A) said media pack being bonded to said first end cap at said first end of said media pack;

(B) said media pack being bonded to said second end cap at said second end of said media pack;

(ii) an inner support liner extending between said first end cap and said second end cap;

(iii) said tint end cap including a sealing portion;

(A) said sealing portion being inwardly directed toward said open interior;

(B) said sealing portion comprising a polyurethane foam material compressed between and against said inner support liner and said airflow tube to form a seal between said primary filter element and said air cleaner housing.

57. A system according to claim 56 wherein:

(a) said primary filter element further including an outer support liner extending between said first and second end caps;

(b) said second end cap defines a center aperture; and

(c) said second end cap includes a sealing portion;

(i) said sealing portion comprising a polyurethane foam material compressed between and against said outer support liner and said air cleaner to form a second seal between said primary filter element and said air cleaner housing.

58. A system according to claim 55 further including:

(a) a safety element operably installed in said air cleaner housing;

said safety element including;

(i) a pleated construction of a media composite;

said safety element pleated construction including a plurality of pleats;

(ii) said safety element pleated construction having a tubular shape and defining an open interior;

(iii) a safety element first end cap and a safety element second end cap;

said safety element pleated construction being bonded to and extending between said safety element first and second end caps;

(A) said safety element first end cap being ring-shaped defining an opening;

(B) said safety element second end cap being closed; and

(iv) said safety element first end cap including an outwardly radially directed sealing portion;

said outwardly radially directed sealing portion comprising a polyurethane material compressible to form a radial seal between said safety element and said air cleaner housing airflow tube.

59. A system according to claim 55 wherein:

(a) said pleated construction has a tubular shape and defines an open interior;

(b) said air cleaner housing includes a yoke arrangement to secure said housing to said primary filter element;

(c) said primary filter element further includes;

(i) a first, open end cap and a second, opposite closed end cap;

(A) said media pack being bonded to said first end cap at said first end of said media pack;

(B) said media pack being bonded to said second end cap at said second end of said media pack;

(c) said first end cap including an axially directed sealing potion;

(d) said axially directed sealing portion being pressed against said air cleaner housing by said yoke arrangement to form an axial seal between said primary filter element and said air cleaner housing.

60. A system according to claim 55 wherein:

(a) said primary filter element includes first and second opposite end caps bonded to said pleated construction;

(i) said first end cap defining a plurality of air inlet apertures and an outlet tube;

(A) said outlet tube being secured to an air intake conduit of said engine;

(ii) said pleated construction being tubular in shape defining an open interior;

(iii) said second end cap being closed; and

(iv) said air cleaner housing being non-removably secured to said first and second end caps.

61. A system according to claim 55 wherein:

(a) said primary filter element comprises

(i) a panel filter construction having an outer perimeter;

(ii) at least 40 pleats;

each of said pleats having a pleat depth of at least 2 inches;

(iii) an area within said outer perimeter of at least 35 square inches; and

(iv) an outer gasket member along said outer perimeter comprising a polymeric material.

62. A system according to claim 33 wherein:

(a) said pleated construction has a tubular shape and defines an open interior;

(b) said air cleaner housing includes a yoke arrangement to secure said housing to said primary filter element;

(c) said primary filter element further includes;

(i) a first, open end cap and a second, opposite closed end cap;

(A) said media pack being bonded to said first end cap at said first end of said media pack;

(B) said media pack being bonded to said second end cap at said second end of said media pack;

(C) said first end cap including an axially directed sealing portion;

(D) said axially directed sealing portion being pressed against said air cleaner housing by said yoke arrangement to form an axial seal between said primary filter element and said air cleaner housing.

63. A system including a vehicle powered by a gas turbine engine end having an air cleaner constructed and arranged to filter gas turbine intake air;

the air cleaner comprising;

(a) a media pack having a first filter panel and a second filter panel;

(i) each of said first filter panel and second filter panel including a pleated construction of a media composite;

said pleated construction, the substrate comprising a filter medium having an efficiency when tested with particles having a diameter of 0.01 to 1 μ

m including a plurality of pleats;

(ii) said media composite including a substrate at least partially covered by a single layer;

(A) said layer comprising a fine fiber having a diameter of about 0.1 to 0.5 microns such that after test exposure for a test period of 16 hours to test conditions of 140°

F. air and a relative humidity of 100% retains greater than 30% of the fiber unchanged for filtration purposes;

said fiber comprising a polymeric composition selected from the group consisting of;

(1) an addition polymer and about 2 to 25 wt % of an additive, the additive comprising a resinous material having a molecular weight of about 500 to 3000 and an aromatic character, the additive being miscible in the polymer but forms a hydrophobic coating on the fiber,

(2) a condensation polymer and about 2 to 25 wt % of an additive, the additive comprising a resinous material having a molecular weight of about 500 to 3000, and an aromatic character wherein the additive is miscible in the condensation polymer but forms a hydrophobic coating on the fiber, and

(3) mixtures thereof.

64. The system of claim 63 wherein the addition polymer comprises a polyvinyl halide polymer, a polyvinylidene halide polymer or mixtures thereof.

65. The system of claim 63 wherein the condensation polymer comprises a nylon polymer comprising a homopolymer having repeating units derived from a cyclic lactam.

66. The system of claim 63 wherein the condensation polymer comprises a nylon copolymer combined with a second nylon polymer, the second nylon polymer differing in molecular weight or monomer composition.

67. The system of claim 63 wherein the polymer comprises a polyvinylalcohol.

68. The system of claim 63 wherein the polyvinylalcohol is crosslinked with about 1 to 40 wt. % of a crosslinking agent.

69. The system of claim 65 wherein the nylon polymer is combined with a second nylon polymer, the second nylon polymer comprising an alkoxy alkyl modified polyamide.

70. The system of claim 69 wherein the polymers are treated to form a single polymeric composition as measured by a differential scanning calorimeter showing a single phase material.

71. The system of claim 63 wherein the polymer comprises a polyvinylchloride.

72. The system of claim 71 wherein the polyvinylchloride is crosslinked.

73. The system of claim 63 wherein the additive comprises an oligomer comprising tertiary butyl phenol.

74. The system of claim 73 wherein the additive comprises an oligomer comprising:

75. The system of claim 63 wherein the additive comprises an oligomer comprising bis-phenol A.

76. The system of claim 75 wherein the additive comprises:

77. The system of claim 63 wherein the additive comprises an oligomer comprising dihydroxy substituted biphenyl.

78. The system of claim 77 wherein the additive comprises:

79. A system according to claim 63 wherein:

(a) said media pack includes a first end and a second end; and

(b) said first and second filter panels are oriented in a V-configuration and diverge from one another along a direction of extension from said first end to said second end to form a clean air space in said media pack between said first and second filter panels.

95. The filter element of claim 63 wherein the vehicle comprises a military tank.

96. The filter element of claim 63 wherein the vehicle comprises a bus.

80. A method for filtering air, the air having a temperature of at least 140°

F., the method comprising;

(a) directing the air through a media composite

(i) the composite comprising a sheet-like substrate in a pleated construction, the substrate comprising a filter medium having an efficiency when tested with particles having a diameter of 0.01 to 1 μ

m; and

(ii) the substrate at least partially covered by a single layer, the layer comprising a fine fiber having a diameter of about 0.1 to 0.5 microns such that after test exposure for a test period of 16 hours to test conditions of 140°

F. air and a relative humidity of 100% retains greater than 30% of the fiber unchanged for filtration purposes, said fiber comprising a polymeric composition selected from the group consisting of;

(A) an addition polymer and about 2 to 25 wt % of an additive, the additive comprising a resinous material having a molecular weight of about 500 to 3000 and an aromatic character, the additive being miscible in the polymer but forms a hydrophobic coating on the fiber,

(B) a condensation polymer and about 2 to 25 wt % of an additive, the additive comprising a resinous material having a molecular weight of about 500 to 3000, and an aromatic character wherein the additive is miscible in the condensation polymer but forms a hydrophobic coating on the fiber; and

(C) mixtures thereof.

81. A method according to claim 80 wherein:

(a) the step of directing the air through a media pack includes directing the air into an air intake conduit of an engine rated at an engine intake air flow of at least 3 cfm;

the pleated construction having a tubular shape with a plurality of pleats extending between first and second opposite end caps.

82. A method according to claim 80 wherein the step of directing the air through a media pack includes directing the air into an air intake conduit of a fluid compressor and the pleated construction being a panel filter with at least 40 pleats each having a pleat depth of at least 2 inches.

83. A method according to claim 80 wherein:

(a) the step of directing the air through a media pack includes directing the air into an air intake conduit of gas-turbine powered tank;

the pleated construction including first and second pleated filter panels oriented in a V-configuration.

84. A filter element comprising:

(a) a media pack comprising;

(i) a construction of a media composite;

said construction including substrate having a plurality of pleats having a length extending from said first end to said second end, the substrate comprising a filter medium having an efficiency when tested with particles having a diameter of 0.01 to 1 μ

m;

(ii) said construction having a tubular shape and defining an open interior having a first and a second opposite ends; and

(iii) said substrate at least partially covered by a single layer;

(A) said layer comprising a polymeric fine fiber having a diameter of about 0.01 to 0.5 microns such that after test exposure for a test period of 16 hours to test conditions of 140°

F. air and a relative humidity of 100% retains greater than 30% of the fiber unchanged for filtration purposes, said fiber comprising a condensation polymer and about 2 to 25 wt % of an additive, the additive comprising a resinous material having a molecular weight of about 500 to 3000, and an aromatic character wherein the additive is miscible in the condensation polymer but forms a hydrophobic coating on the fiber, said condensation polymer comprising a copolymer other than a copolymer formed from a cyclic lactam and a C_6-10 diamine monomer or a C_6-10 diacid monomer;

(b) a first end cap and a second end cap;

(i) said media pack being secured to said first end cap at said first end of said media pack;

(ii) said media pack being secured to said second end cap at said second end of said media pack;

(iii) at least one of said first and second end caps including a sealing portion;

said sealing portion comprising a material compressible in a direction toward said media pack.

85. The element of claim 84 wherein the polymer of the fiber is formed from a component of a solution, the solution comprising a major proportion of an aqueous alcoholic solvent and about 3 to 30 wt % of the polymeric composition based on the solution and retains trace amounts of solvent in the fiber.

86. The element of claim 84 wherein the condensation polymer comprises a polyalkylene terephthalate.

87. The element of claim 84 wherein the condensation polymer comprises a polyalkylene naphthalate.

88. The element of claim 87 wherein the condensation polymer comprises a polyethylene terephthalate.

89. The element of claim 84 wherein the condensation copolymers is combined with a second nylon polymer, the second nylon polymer differing in molecular weight or monomer composition.

90. The element of claim 84 wherein the condensation copolymer is combined with a second nylon polymer, the second nylon polymer comprising an alkoxy alkyl modified polyamide.

91. A filter element according to claim 84 wherein:

(a) said first end cap is ring-shaped defining an open center and includes an inner surface facing the open center;

(i) said scaling portion comprising said inner surface.

92. A filter element according to claim 84 further including:

(a) an inner support liner extending between said first end second end caps;

(i) said inner support liner being between said scaling portion and said media pack.

93. A filter element according to claim 84 wherein:

(a) at least one of said first and second end caps includes an outer radial surface;

(i) said scaling portion comprising said outer radial surface.

94. A filter element according to claim 84 further including:

(a) an inner support liner extending between said first and second and caps;

(b) an outer support liner, extending between said first and second end caps; and

wherein;

(i) each of said plurality of pleats bas a pleat length of at least 6 inches and a pleat depth of at least 1 inch.

97. A method for filtering vehicle cabin ventilation air, the vehicle having a temperature of at least 140°

F. during any period of operation, the method comprising;

(a) directing the air through a media composite

(i) the composite comprising a substrate in a pleated construction, the substrate comprising a filter medium having an efficiency when tested with particles having a diameter of 0.01 to 1 μ

m; and

(ii) the substrate at least partially covered by a single layer, the layer comprising a fine fiber having a diameter of about 0.1 to 0.5 microns such that after test exposure for a test period of 16 hours to test conditions of 140°

F. air and a relative humidity of 100% retains greater than 30% of the fiber unchanged for filtration purposes, said fiber comprising a polymeric composition selected from the group consisting of;

(A) an addition polymer and about 2 to 25 wt % of an additive, the additive comprising a resinous material having a molecular weight of about 500 to 3000 and an aromatic character, the additive being miscible in the polymer but forms a hydrophobic coating on the fiber,

(B) a condensation polymer and about 2 to 25 wt % of an additive, the additive comprising a resinous material having a molecular weight of about 500 to 3000, and an aromatic character wherein the additive is miscible in the condensation polymer but forms a hydrophobic coating on the fiber; and

(C) mixtures thereof.

98. A method according to claim 97 wherein:

(a) the step of directing the air through a media pack includes directing the air into an air intake conduit of an engine rated at an engine intake air flow of at least 3 cfm;

the pleated construction having it tubular shape with a plurality of pleats extending between first and second opposite end caps.

99. A method according to claim 98 wherein the step of directing the air through a media pack includes directing the air into an air intake conduit of a fluid compressor and the pleated construction being a panel filter with at least 40 pleats each having a pleat depth of at least 2 inches.

100. A method according to claim 99 wherein:

(a) the step of directing the air through a media pack includes directing the air into an air intake conduit;

the pleated construction including first and second pleated filter panels oriented in a V-configuration.