|Publication number||US20080203614 A1|
|Application number||US 12/114,931|
|Publication date||Aug 28, 2008|
|Filing date||May 5, 2008|
|Priority date||Nov 24, 2004|
|Also published as||DE102005040623A1, DE102005040623B4, US7413588, US20060107638|
|Publication number||114931, 12114931, US 2008/0203614 A1, US 2008/203614 A1, US 20080203614 A1, US 20080203614A1, US 2008203614 A1, US 2008203614A1, US-A1-20080203614, US-A1-2008203614, US2008/0203614A1, US2008/203614A1, US20080203614 A1, US20080203614A1, US2008203614 A1, US2008203614A1|
|Inventors||Mark V. Holzmann, Kelly Ann Detra, Jim L. Alonzo, Chirag D. Parikh, Gregory J. Schoenmann, Michael J. Connor, Gary L. Rickle, Barry M. Verdegan|
|Original Assignee||Fleetguard, Inc., An Indiana Corporation|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (6), Classifications (13)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The invention relates to filters, and more particularly to a high efficiency, low restriction, cost effective filter.
There is continuing demand for fluid filters exhibiting high efficiency and low restriction at reduced cost. The present invention addresses and solves this need in a simple and effective manner.
In one desirable option, an incinerable and/or recyclable filter is provided, enabling green label product designation, which is significant in various markets.
Frame 22 a of framework 21 is along the exterior 20 a of filter media 20. Frame 22 b of framework 21 is along the interior 20 b of filter media 20. Filter media 20 is preferably sandwiched between the noted exterior and interior sets of ribs on opposite exterior and interior sides 20 a, 20 b thereof and bonded respectively thereto. In one embodiment, the filter is an outside-in filter wherein fluid to be filtered flows laterally inwardly through the filter media as shown at arrows 32 into the hollow interior of the filter, and then the clean filtered air flows axially rightwardly in
Ribs 26 a, 26 b, 28 a, 28 b are bonded to filter media 20 by at least one of, and preferably both of, a) a chemical bond and b) a mechanical bond. Filter media 20 is composed of material selected from the group consisting of synthetic, glass, cellulose, ceramic, carbon, and metallic material. In a preferred embodiment, in combination each of framework 21 and filter media 20 is composed of material selected from the group consisting of organic, synthetic, and polymeric material selected such that filter element 12 is incinerable. In a further embodiment, each of framework 21 and filter media 20 is composed of thermoplastic material, and further preferably in combination the material of framework 21 and the material of filter media 20 are of the same thermoplastic recycling class such that filter element 12 is recyclable. Further in the preferred embodiment, filter media 20 is composed of fibers, and the material of framework 21 is selected from a family chemically compatible with the material of the fibers to chemically bond ribs 26 a, 26 b, 28 a, 28 b of framework 21 to filter media 20, and also such that the plastic material of the ribs entangles some of the media fibers to additionally mechanically bond the ribs of the framework to the filter media, such that the ribs of the framework are both chemically and mechanically bonded to filter media 20. In one embodiment, filter media 20 is provided by polyester fibers, and the material of framework 21 is selected from the group consisting of polyester, polypropylene, and resin. In one embodiment, the material of framework 21 is polyester selected from the same polymeric family as the noted polyester fibers of filter media 20 to chemically bond ribs 26 a, 26 b, 28 a, 28 b of framework 21 to filter media 20, and also such that the polyester plastic of ribs 26 a, 26 b, 28 a, 28 b of the framework entangles some of the polyester media fibers to additionally mechanically bond ribs 26 a, 26 b, 28 a, 28 b of the framework to the filter media 20, such that ribs 26 a, 26 b, 28 a, 28 b are both chemically and mechanically bonded to filter media 20. In one embodiment, the material of framework 21 is polyester with glass reinforcement. In another embodiment, the material of framework 21 is polypropylene, and the polypropylene plastic of ribs 26 a, 26 b, 28 a, 28 b of the framework entangles some of the polyester media fibers to mechanically bond plastic framework 21 to filter media 20. In one embodiment, the framework material is polypropylene with glass reinforcement. In another embodiment, the framework material is polypropylene with talc reinforcement. In a further embodiment, the material of framework 21 is a plastic resin.
In further preferred embodiments, the material of filter media 20 is PET (polyethyleneterephthalate) non-woven polyester. The material of framework 21 is preferably chosen from two different plastic families. In the first family, the material of framework 21 is that known under the tradename RYNITE 415HP-BLACK, DuPont Rynite PET Polyester. This type of formulation, involving 15% glass reinforcement with a toughener added in the formulation, was selected because it provides the same polymeric family to be melt bonded during injection molding of the framework to provide a PET plastic to PET media bond, resulting in a more robust structural construction including between media fibers and an integrally molded rib network 24 a, 24 b and because such polymeric bond also provides some plastic working its way through the fibers of the filter media and providing a mechanical bond as well. This selection was also made because the enhanced robustness provides additional vacuum resistance under severe conditions, including a wet dirty fully loaded primary filter failure when the present filter is used as a secondary filter in combination, to be described. This selection was also made because the enhanced robustness provides additional torsional loading resistance including under severe conditions including loading and unloading during service. This selection was also made because the enhanced robustness provides additional columnar collapse buckling resistance under severe service conditions, including installation with highly compressive loads. This selection was also made because it provides more heat resistance than polypropylene. In the second family, 20% glass-filled or 30% talc-filled polypropylene is selected, with a formulation involving 20% glass reinforcement with a toughener added in the formulation. This selection provides more economical pricing. This selection also provides a dissimilar polymeric family to be mechanically melt bonded via polymer chain entanglement amongst the filter media fibers during the injection molding sequence during molding of framework 21 to provide a polypropylene plastic to PET filter media mechanical bond. This results in a robust structural construction between PET filter media fibers and the integrally molded rib network 24. The remaining reasons for this selection are similar to those above indicated for the first noted family, except that this second family is preferably not used in hot environments above about 180° F. because the plastic of the framework may deflect more easily under loads. Other resins may be used, such as nylon, ABS (acrylonitrile/butadiene/styrene), PPS (polyphenylene sulfide), and the like.
Framework 21 extends axially along axis 14 between distally opposite first and second axial ends 36 and 38 at the noted respective first and second axial ends of the filter element. Framework 21 at the noted ribs is molded to and bonded to filter media 20 along the axial extension thereof. The noted first end 36 of the framework has an outer peripheral surface 40 having one or more resilient seals 42,
The integral flex seal rings provided by flanges 42 provide not only a flexible seal but also a spring-type retention by forcing the flex rings provided by flanges 42 into a drafted surface, preferably conical. This eliminates the need for providing a seal from urethane potting as in the prior art. The thickness of the rings is selected to provide enough retention under vibration to hold the filter in place and prevent axial backing-out thereof. The retention force is selected so as not to have too much interference, otherwise making installation and extraction difficult, but still provide enough retention to resist vibration induced axial back-out. In a further embodiment, if vibration back-out is of concern, an interference fit retention mechanism may be provided, for example as shown in U.S. Pat. No. 6,383,244, incorporated herein by reference, and further described hereinafter. In such embodiment, intermittent detent undercuts may be provide to hold back the end-most flex ring flange 42 (rightmost in
It is significant that filter element 12 is a two-piece assembly consisting, in the preferred embodiment, solely of two components, namely filter media 20 and plastic framework 21 molded thereon. The plastic framework includes a resilient seal 42 integrally molded therewith and of the same plastic material thereof, eliminating a separate component for the seal, such that the filter element remains a two-component assembly, including the seal. The framework extends axially along axis 14 between distally opposite first and second axial ends at the noted first and second axial ends of the filter element. Framework 21, including first and second frames 22 a and 22 b, is an integrally molded singular component, including integral connection between frames 22 a and 22 b at at least one of and preferably both of the noted first and second axial ends 38 and 40. The filter element remains a two-component assembly consisting solely of two components, namely filter media 20 and framework 21 molded thereon.
Secondary filter element 12 in
Further embodiments include pleated and non-pleated filter media used with a plastic framework having only an outer frame or only an inner frame or both an outer frame and an inner frame.
In further preferred embodiments, the filter media is oiled and die cut and then sonically welded into a conical pre-form before it is overmolded with the plastic framework. The seam from the sonic weld is aligned along one of the noted axial ribs, so that the seam is sealed by and bonded to the plastic, minimizing a possible leak path. Stand-offs such as 19 are provided at end 38 to space the end of the media slightly from the end of the mold so that the molten plastic is free to flow around the media to both the inner and outer ribs at such end. Inner trusses, comparable to trusses 44, may be provided on the interior of the element for stress bearing. The molten plastic is preferably injected at end 36, and media end 18 may include portions which are recessed or otherwise slightly pushed away from the axial end to provide a flow path for the molten plastic and to prevent damming thereat.
It is recognized that various equivalents, alternatives and modifications are possible within the scope of the appended claims. Each of the noted annular filter elements is preferably a circular annulus, though other annular shapes may be used, including elliptical, racetrack-shaped, and other closed-loop annuli. The shapes may or may not be frusto-conically tapered. The teachings of the invention may further be applied to flat panel filter elements, as well as other shapes. The noted ribs may alternatively be provided by applying heated bars to partially melt and flatten sections of the filter media into a ribbed structure, i.e. ironing ribs into the media. The preferred implementation is an air filter, though other fluid filter applications are possible. In an air filter, the open areas between the ribs can be larger, since there are lower pressure drop requirements than a liquid filter. For ease of service, a circular seal may be preferred between the filter element and the housing, for example at seal 42 and the housing at flange 114. In a desirable implementation, the filter element is installed by pressing it or slightly twisting it into the receptacle housing at 114 while applying pressure. The louvered, annular barbs at 42 seal against the internal surface at 114 of the circular mounting hole in the housing, a duct, or an air handling conduit. As the filter element slides into the receptacle, semi-rigid semi-flexible plastic or thermoplastic barbs 42 flex slightly inwardly, and preferably semi-rigid semi-flexible plastic or thermoplastic walls of the receptacle at 114 flex slightly outwardly, to secure and seal the filter element. A radial seal is formed between the one or more flexible barbs 42 and the receptacle at flange 114, and, if desired, an axial face seal can be formed where the axial end 36 of the filter element meets the facing annular surface of the receptacle. To remove the filter element, the service technician twists and/or applies a lateral force to free the face of the filter element from the holder at 114. In a further embodiment, the filter element is an annular filter element 12 extending axially along axis 14 between the noted distally opposite first and second axial ends 16 and 18, and framework 21 extends axially along axis 14 between distally opposite first and second axial ends 36 and 38 at respective first and second axial ends 16 and 18 of filter element 12, and the noted first end of the framework has inner and outer peripheral surfaces, and the noted resilient seal is integrally molded with at least one of such surfaces.
|Citing Patent||Filing date||Publication date||Applicant||Title|
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|US8562708||Apr 29, 2011||Oct 22, 2013||Diversitech Corporation||Three-dimensional filter|
|US8591621 *||Apr 1, 2009||Nov 26, 2013||Mann+Hummel Gmbh||Filter system|
|US8709320||Sep 21, 2012||Apr 29, 2014||Diversitech Corporation||Three-dimensional filter|
|US20110094197 *||Apr 1, 2009||Apr 28, 2011||Mann+Hummel Gmbh||Filter System|
|WO2011137367A1 *||Apr 29, 2011||Nov 3, 2011||Diversitech Corporation||Three-dimensional filter|
|Cooperative Classification||B01D46/0005, B01D46/0024, B01D2265/06, B01D2265/04, B01D46/2411, B01D46/521, Y10S210/17|
|European Classification||B01D46/00C20, B01D46/24F4, B01D46/52F, B01D46/00D4A|