US6428610B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hepa filter
Assignee: TENNESSE UNIVERSITY OF RESEARCH Corp
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Filing: 2000-01-18
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Granted: 2002-08-06
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Expires: 2020-01-18
Abstract
Abstract The present invention is directed toward a filter media for a high efficiency particulate air (“HEPA”) filter including a multiplicity of adjacent electrostatically charged piles of nonwoven fabric. The invention further includes a method of making a HEPA filter.
Inventors
- 👤 Peter Tsai
- 👤 Sanjiv R. Malkan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:51
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/52; B01D46/521; B01D39/00; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; B01D39/163; B01D46/0001; B01D46/0027; B01D46/0028; B01D46/10; B03; B03C; B03C3/00; B03C3/02; B03C3/04; B03C3/14; B03C3/155; B03C3/28; B01D2275/00; B01D2275/10; B01D2279/00; B01D2279/50; B01D2279/51; Y; Y10; Y10S; Y10S264/00; Y10S264/48; Y10S55/00; Y10S55/05; Y10S55/39
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
127 words
A particulate air filter media comprising: a. a first pile of charged nonwoven fabric having a weight in the range of 5-40 grams per square meter and one or more fibers having a diameter in the range of 1.5-2.0 microns; b. a second pile of nonwoven fabric having a weight in the range of 5-40 grams per square meter and one or more fibers having a diameter in the range of 1.5-2.0 microns, adjacent to said first pile; c. a third pile of nonwoven fabric having a weight in the range of 5-40 grams per square meter and one or more fibers having a diameter in the range of 1.5-2.0 microns, adjacent to said second pile; and d. a stiffening layer bonded to one of said piles.
Claim 2
Dependent Claim
127 words
A particulate air filter media comprising: a. a first pile of charged nonwoven fabric having a weight in the range of 5-40 grams per square meter and one or more fibers having a diameter in the range of 1.5-2.0 microns; b. a second pile of nonwoven fabric having a weight in the range of 5-40 grams per square meter and one or more fibers having a diameter in the range of 1.5-2.0 microns, adjacent to said first pile; c. a third pile of nonwoven fabric having a weight in the range of 5-40 grams per square meter and one or more fibers having a diameter in the range of 1.5-2.0 microns, adjacent to said second pile; and d. a stiffening layer bonded to one of said piles.
Claim 3
Dependent Claim
34 words
The filter media of claim 1 further comprising a fourth pile adjacent to said third pile, and wherein the weight of each pile is less than or equal to 35 grams per square meter.
Claim 4
Dependent Claim
34 words
The filter media of claim 2 further comprising a fifth pile adjacent to said fourth pile and wherein the weight of each pile is less than or equal to 25 grams per square meter.
Claim 5
Dependent Claim
34 words
The filter media of claim 3 further comprising a sixth pile adjacent to said fifth pile, and wherein the weight of each pile is less than or equal to 20 grams per square meter.
Claim 6
Dependent Claim
14 words
The filter media of claim 1 wherein said nonwoven fabric is a meltblown fabric.
Claim 7
Dependent Claim
12 words
The filter media of claim 5 wherein said meltblown fabric comprises polypropelene.
Claim 8
Dependent Claim
30 words
The filter media of claim 1 wherein the bonding area of said stiffening layer is in the range of 0.1% to 30% of the surface area of the bonded pile.
Claim 9
Dependent Claim
31 words
The filter media of claim 7 wherein said bonding is ultrasonic bonding and said bonding area is greater than or equal to 1% of the surface area of the bonded pile.
Claim 10
Dependent Claim
14 words
The filter media of claim 7 wherein said stiffening layer comprises a spunbond fabric.
Claim 11
Dependent Claim
90 words
A particulate air filter comprising: a. at least three adjacent piles of charged nonwoven fabric, each of said piles having a weight in the range of 5-40 grams per square meter and comprising one or more fibers having a diameter in the range of 1.5-2.0 microns, said piles comprising a first outer surface and a second outer surface; and b. a first stiffening layer bonded to said first outer surface such that the bonding area is in the range of 0.1-30% of the surface area of said first outer surface.
Claim 12
Dependent Claim
90 words
A particulate air filter comprising: a. at least three adjacent piles of charged nonwoven fabric, each of said piles having a weight in the range of 5-40 grams per square meter and comprising one or more fibers having a diameter in the range of 1.5-2.0 microns, said piles comprising a first outer surface and a second outer surface; and b. a first stiffening layer bonded to said first outer surface such that the bonding area is in the range of 0.1-30% of the surface area of said first outer surface.
Claim 13
Dependent Claim
38 words
The filter of claim 10 , further comprising a second stiffening layer bonded to said second outer surface such that the bonding area is in the range of 0.1-30% of the surface area of said second outer surface.
Claim 14
Dependent Claim
13 words
The filter of claim 10 , wherein said nonwoven fabric comprises meltblown polypropelene.
Claim 15
Dependent Claim
34 words
The filter of claim 10 further comprising a fourth pile adjacent to said second outer surface and wherein the weight of each pile is less than or equal to 35 grams per square meter.
Claim 16
Dependent Claim
33 words
The filter of claim 13 further comprising a fifth pile adjacent to said fourth pile and wherein the weight of each pile is less than or equal to 25 grams per square meter.
Claim 17
Dependent Claim
33 words
The filter of claim 14 further comprising a sixth pile adjacent to said fifth pile, and wherein the weight of each pile is less than or equal to 20 grams per square meter.
Claim 18
Independent Claim
115 words
A method of making a particulate air filter comprising: a. charging at least three adjacent piles of nonwoven fabric, each of said piles having a weight in the range of 5-40 grams per square meter, and each of said piles comprising one or more fibers having a diameter in the range of 1.5-2.0 microns; b. collating a stiffening layer of fabric with said piles; c. bonding the stiffening layer to one of said piles to form a stiffened filter media having a top side and a bottom side; d. scoring said stiffened filter media; e. folding said stiffened filter media into a multiplicity of adjacent layers; and f. inserting a separator between two adjacent layers.
Claim 19
Independent Claim
115 words
A method of making a particulate air filter comprising: a. charging at least three adjacent piles of nonwoven fabric, each of said piles having a weight in the range of 5-40 grams per square meter, and each of said piles comprising one or more fibers having a diameter in the range of 1.5-2.0 microns; b. collating a stiffening layer of fabric with said piles; c. bonding the stiffening layer to one of said piles to form a stiffened filter media having a top side and a bottom side; d. scoring said stiffened filter media; e. folding said stiffened filter media into a multiplicity of adjacent layers; and f. inserting a separator between two adjacent layers.
Claim 20
Dependent Claim
12 words
The method of claim 16 wherein said separator is made from aluminum.
Claim 21
Dependent Claim
12 words
The method of claim 16 , wherein said bonding is ultrasonic bonding.
Claim 22
Independent Claim
133 words
A method of making a particulate air filter comprising: a. charging at least three adjacent piles of nonwoven fabric, each of said piles having a weight in the range of 5-40 grams per square meter, and each of said piles comprising one or more fibers having a diameter in the range of 1.5-2.0 microns; b. collating a stiffening layer with said piles; c. bonding the stiffening layer of fabric to one of said piles to form a stiffened filter media having a top side and a bottom side; d. scoring said stiffened filter media; e. applying glue to a side of said stiffened filter media; f. folding said filter media into a series of V shaped pleats; and g. cutting said pleated filter media into a multiplicity of pieces having a predetermined size.
Claim 23
Independent Claim
133 words
A method of making a particulate air filter comprising: a. charging at least three adjacent piles of nonwoven fabric, each of said piles having a weight in the range of 5-40 grams per square meter, and each of said piles comprising one or more fibers having a diameter in the range of 1.5-2.0 microns; b. collating a stiffening layer with said piles; c. bonding the stiffening layer of fabric to one of said piles to form a stiffened filter media having a top side and a bottom side; d. scoring said stiffened filter media; e. applying glue to a side of said stiffened filter media; f. folding said filter media into a series of V shaped pleats; and g. cutting said pleated filter media into a multiplicity of pieces having a predetermined size.
Claim 24
Dependent Claim
11 words
The method of claim 19 wherein said bonding is ultrasonic bonding.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-08-05 | 2006-02-04 | 2006-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-08-05 | 2010-02-04 | 2010-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-08-05 | 2014-02-04 | 2014-08-06 | $7700.00 | Window Closed / Lapsed |