Filter medium and breather filter structure

• US 9,795,906 B2
• Filed: 12/19/2013
• Issued: 10/24/2017
• 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., Kahlbaugh, Brad E., Olson, Linda M., Yang, Chuanfang, LaVallee, Gregory L., Sporre, Timothy D., Israel, Joe, Kojetin, Paul L., Jones, Derek O., Madden, Michael A.
• Primary Examiner(s): CLEMENTE, ROBERT ARTHUR
• Application Number:
  US14/134,604
• Publication Number:
  US 20140197094A1
• Time in Patent Office: 1,405 Days
• 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
• 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
• 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 nonwoven filtration medium comprising:

a loading layer having an average pore size of 5 to 30 micrometers, wherein the loading layer comprises bicomponent fibers and glass fibers, wherein the bicomponent fibers have a concentric sheath-core structure; and

an efficiency layer having an average pore size of 0.5 to 3 micrometers.

2. The nonwoven filtration medium of claim 1 wherein the efficiency layer has a permeability of 5 to 30 ft-min⁻

1 and the loading layer has a permeability of 50 to 200 ft-min<sup>−

1</sup>.

3. The nonwoven filtration medium of claim 1 further comprising a fluoro-organic compound.

4. A multilayer nonwoven filtration medium comprising:

a loading layer having an average pore size of 5 to 30 micrometers; and

an efficiency layer having an average pore size of 0.5 to 3 micrometers;

wherein one or more layers comprise bicomponent binder fibers and glass fibers.

5. The multilayer nonwoven filtration medium of claim 4 which has a permeability of 4 to 20 ft-min⁻

1, a wet burst strength of 10 lb-in<sup>−

2</sup> to 20 lb-in<sup>−

2</sup>, and a basis weight of 100 g-m<sup>−

2</sup> to 200 g-m<sup>−

2</sup>.

6. The multilayer nonwoven filtration medium of claim 4 further comprising a fluoro-organic compound.