Filter medium and breather filter structure

• US 8,641,796 B2
• Filed: 09/14/2012
• Issued: 02/04/2014
• Est. Priority Date: 11/05/2004
• Status: Active Grant

• Current Assignee: Donaldson Company Incorporated
• Original Assignee: Donaldson Company Incorporated
• Inventors: Rogers, Robert M., Dema, Keh B.
• Primary Examiner(s): Clemente, Robert
• Application Number:
  US13/616,088
• Publication Number:
  US 20130008846A1
• Time in Patent Office: 508 Days
• Field of Search: 555/27, 555/28, 554/86, 554/87, 210/505, 210/508, 210/509
• US Class Current: 55/527
• CPC Class Codes: B01D 2239/0216 Bicomponent or multicomponent fibres
• 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 2239/0668 The layers being joined by heat or melt-bonding
• CPC Class Codes: B01D 2275/10 Multiple layers
• CPC Class Codes: B01D 2279/60 for the intake of internal combustion engines or turbines intake systems for vehicles comprising filters F02M35/024
• CPC Class Codes: B01D 39/1615 of natural 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 39/2017 the material being filamentary or fibrous
• CPC Class Codes: B01D 39/2024 otherwise bonded, e.g. by resins
• CPC Class Codes: B01D 39/2037 otherwise bonded
• 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 46/71 with pressurised gas, e.g. pulsed air
• CPC Class Codes: Y10T 442/616 Blend of synthetic polymeric and inorganic microfibers
• CPC Class Codes: Y10T 442/622 Microfiber is a composite fiber
• CPC Class Codes: Y10T 442/623 Microfiber is glass
• CPC Class Codes: Y10T 442/637 Including strand or fiber material which is a monofilament composed of two or more polymeric materials in physically distinct relationship [e.g., sheath-core, side-by-side, islands-in-sea, fibrils-in-matrix, etc.] or composed of physical blend of chemically different polymeric materials or a physical blend of a polymeric material and a filler material

Abstract

Thermoplastic bicomponent binder fiber can be combined with other media, fibers and other filtration components to form a thermally bonded filtration media. The filtration media can be used in filter units, such as breather caps. Such filter units can be placed in the stream of a mobile fluid and can remove a particulate and/or fluid mist load from the mobile stream. The unique combination of media fiber, bicomponent binder fiber and other filtration additives and components provide a filtration media having unique properties in filtration applications.

Claims

1. A thermally bonded nonwoven filter medium comprising about 10 to 90 wt % of a bicomponent fiber comprising a diameter of 5 to 50 microns, and about 10 to 90 wt % of a media fiber comprising a diameter of 0.1 to 5 microns, wherein the filter medium comprises a thickness of about 0.25 to 1.9 mm, a pore size of about 0.2 to 50 microns, a permeability of about 2 to 200 ft-min⁻

1, a solidity of about 2 to 25%, and a basis weight of about 2 to 200 g-m<sup>−

2</sup>.

2. A filter element comprising two or more layers of the filter medium of claim 1.

3. The filter element of claim 2 further comprising a mechanical support.

4. The filter element of claim 3 wherein the mechanical support is a perforate support, wire support, or scrim.

5. The filter medium of claim 1 wherein the bicomponent fiber comprises a polyester.

6. The filter medium of claim 1 wherein the bicomponent fiber comprises a nylon.

7. The filter medium of claim 1 wherein the media fiber is a cellulosic media fiber or a synthetic media fiber.

8. The filter medium of claim 7 wherein the synthetic media fiber comprises polyester, nylon or polyolefin.

9. The filter medium of claim 1 wherein the media fiber comprises a combination of a cellulosic fiber and at least one of polyester, nylon or polyolefin.

10. A filter element comprising the filter medium of claim 1 and an additional filter medium, the additional filter medium different from the filter medium of claim 1.

11. The filter element of claim 10 comprising two or more layers of the filter medium of claim 1, the additional filter medium, or both.

12. The filter element of claim 11 further comprising a mechanical support.

13. The filter element of claim 12 wherein the mechanical support is a perforate support, wire support, or scrim.