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EP-4324542-B1 - SURFACE COATED FILTER

EP4324542B1EP 4324542 B1EP4324542 B1EP 4324542B1EP-4324542-B1

Inventors

  • KRULL, TIMOTHY L
  • EPPERSON, Matthew K
  • POKORNEY, Daniel P
  • VON SEGGERN, Michael J

Dates

Publication Date
20260506
Application Date
20170209

Claims (14)

  1. A filter element (10; 400; 500), comprising: a filter media pack (12; 212; 412; 512) including an outer surface (14; 214), the outer surface (14; 214) extending between a first flow face (16; 216; 416; 516) and a second flow face (18; 218; 418; 518); a polymeric coating (20; 220; 420; 520) applied to the outer surface (14; 214) of the filter media pack, wherein the polymeric coating (20; 220; 420; 520) is not a molded structure, and wherein the polymeric coating (20; 220; 420; 520) is polyurea.
  2. The filter element of claim 1, further comprising a border gasket (30) having housing sealing surface, the border gasket (30) secured to the polymeric coating (20; 220; 420; 520) in surrounding relation to the filter media pack 12; 412; 512, wherein the border gasket (30) is molded in place and integrally bonded to the polymeric coating (20; 220; 420; 520).
  3. The filter element of claim 2, wherein the border gasket (30) is formed from a seal material being of a compatible bonding material to the polymeric coating (20; 220; 420; 520) and comprising at least one of polyurethane, urethane, and silicone.
  4. The filter element of claim 1, wherein the polymeric coating (20; 220; 420; 520) has a surface roughness of between about 1.27 µm and 254 µm (50 and about 10,000 µin), more preferably the surface roughness is at least 25.4 µm (1,000 µin), and most preferably at least 127 µm (5,000 µin); and preferably the surface roughness is less than 229 µm (9,000 µin) and more preferably less than 178 µm (7,000 µin).
  5. The filter element of claim 1, wherein the polymeric coating (20; 220; 420; 520) penetrates the filter media pack (12; 212; 412; 512) to a depth of at least 229 µm (9,000 µin).
  6. The filter element of claim 1, wherein the polymeric coating (20; 220; 420; 520) comprises a spray coating layer.
  7. The filter element of claim 1, wherein the polymeric coating (20; 220; 420; 520) has a Shore A Durometer hardness of between about 60 and about 95.
  8. The filter element of claim 1, wherein the polymeric coating (20; 220; 420; 520) includes fiberglass, roughening agents, or other fillers.
  9. The filter element of claim 1, wherein the filter media pack (12) is constructed of a filter media and comprises a fluted filter media filter pack comprising a face sheet (26) and a fluted sheet (28) in a wound or stacked configuration for form a plurality of layers such that unfiltered fluid must pass through the face sheet (26) or the fluted sheet (28) to pass from the first flow face (16) to the second flow face (18).
  10. The filter element of claim 9, wherein the fluted filter media filter pack (212) is a wound pack having an annular shape, a leading edge (252) of the wound pack being in a radial center (250) of a pack (212) and a trailing edge (252) of the wound pack being along the outer surface (214) forming a step (256), the polymeric coating (220) filling in and sealing the step (256) and preventing unfiltered fluid flow leakage from the first flow face (216) to the second flow face (218), without any additional materials applied along the step between the polymeric coating (220) and the fluted filter media filter pack (12; 212; 412; 512).
  11. The filter element of claim 1, wherein the filter media pack first flow face (16; 216; 416; 516) and the second flow face (18; 218; 418; 518) are free of the polymeric coating, or wherein the polymeric coating (20; 220; 420; 520) has been applied to at least 25% of a surface area of the outer surface (14; 214) between the first (16; 216; 416; 516) and second flow faces (18; 218; 418, 518).
  12. The filter element of claim 1, wherein the filter media pack (12; 212; 412; 512) maintains its volume during a storage period after the polymeric coating (20; 220; 420; 520) has been applied, the polymeric coating (20; 220; 420; 520) restraining the media pack from expanding and limiting any expansion in perimeter of the outer surface (14; 214) to less than 5%, when subjected to 100% humidity for a period of 48 hours.
  13. The filter element according to claim 1, wherein said filter media forms the outer surface (14; 214) of the filter media pack.
  14. The filter element according to claim 1, wherein the polymeric coating (20; 220; 420; 520) provides a complete surrounding seal between the filter media pack (12; 212; 412; 512) and at least one of housing gasket or a metal or plastic preformed component part.

Description

FIELD OF THE INVENTION This invention generally relates to filters, and more particularly, to a coating of the exterior surface of a filter media pack. BACKGROUND OF THE INVENTION Filter media packs are often wrapped with a fabric or paper to enhance the aesthetics of the block of filter media as well as to protect the filter media during handling. Conventionally, the paper wraps are heavy cardstock, and the fabric wraps are polyester nonwovens. These wraps provide some reinforcement for the filter media packs, but they do not protect the filter media from puncturing if dropped or gouged during handling or installation. Additionally, these wraps do not provide strong bonding surfaces for attaching structures, such as seal members or mounting frames, which allows the attached structures to easily tear off. Further, these wraps are often difficult to bind to the filter media, which creates leak paths around the filter media pack. In some instances, the filter media is not coated or covered as discussed in U.S. Patent No. 7,396,376 to Schrage et al. However, outer skins or protective layers are also proposed as evidenced by U.S. Patent Nos. 4,410,427 and 6,743,317, both to Wydeven, U.S. Patent No. 5,820,646 to Gillingham et al, and Japanese Utility Model S60-155921 to Tuchyiya Seisakusho Limited. Additionally, molding techniques for such layers are proposed in U.S. Patent No. 7,967,886 to Schrage et al., but this proposal requires substantial space and complex, expensive molding tooling and operation. Other slip resistant and textured surface layers have been proposed, including U.S. Publication No. 2014/0217009 by Osterfeld and U.S. Patent No. 6,080,310 to Bolser et al. WO 2007/056589 and WO 2009/039285 disclose filter elements. Various improvements in the durability, handling, and leak prevention of filter media packs not previously realized in the art can be realized with different aspects or embodiments of the present invention as presented below, thus demonstrating such shortcomings in the state of the art. BRIEF SUMMARY OF THE INVENTION The inventive aspects and embodiments discussed below in the following separate paragraphs of the summary may be used independently or in combination with each other. In one aspect, a filter element is provided as defined in appended claim 1. Another aspect is directed to a polymeric coating can have a surface roughness of at least 1.27 µm (50 µin). In preferred embodiments, the surface roughness is between about 2.54 µm and about 254 µm (about 100 and about 10,000 µin). The polymeric coating preferably penetrates the filter media pack to a depth of at least 228.6 µm (9,000 µin). In preferred embodiments, the polymeric coating can be a spray coating layer. Spraying has several advantages. In other embodiments, the polymeric coating can be a roll coating layer. In order to enhance protection of the filter element during handling, the polymeric coating preferably has a Shore A Durometer hardness of between about 60 and about 95. Thus, the polymeric coating is harder than conventional non-woven or paper wraps that are easily punctured or crushed if mishandled. The polymeric coating can include more than one layer, such as at least two layers. The polymeric coating can optionally include fiberglass, roughening agents or other fillers. The polymeric coating can be applied to a variety of filter element types. In one embodiment, the filter media pack is constructed of a filter media that includes a fluted filter media filter pack having a face sheet and a fluted sheet in a wound or stacked configuration. Unfiltered fluid passes through the face sheet or the fluted sheet to pass from the first flow face to the second flow face. In preferred embodiments, a span from the first flow face to the second flow face is at least 8 centimeters. Additionally, the fluted filter media filter pack can be a wound pack having an annular shape. A leading edge of the wound pack is located at a center of the pack, and a trailing edge of the wound pack terminates along the outer surface, forming a step on the outer surface. The polymeric coating fills in and seals the step, preventing unfiltered fluid flow leakage from the first flow face to the second flow face. Preferably, no additional materials are applied along the step between the polymeric coating and the fluted filter media filter pack. In another embodiment, the filter element is a pleated filter element constructed of a filter media having a plurality of pleat flanks extending between pleat tips at the first flow face and pleat tips at the second flow face. The filter element is configures in such a way that unfiltered fluid must pass through the filter media to pass from the first flow face to the second flow face. The polymeric coating is applied to a leading-most pleat flank and a trailing-most pleat flank and, optionally, along edges of the pleat flanks that extend transverse to the leading-most pleat flank and the trailing-most pleat