Patent US4650506A successfully refreshed from Google Patents.
US4650506A
Expired / Lapsed
US
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Multi-layered microfiltration medium
Assignee: Donaldson Co Inc
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Filing: 1986-02-25
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Granted: 1987-03-17
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Expires: 2006-02-25
Abstract
Abstract A multilayered microfiltration medium exhibiting high particle capture efficiency and minimal flow restriction having a base substrate layer, a fine fiber filtration or efficiency layer deposited on and adhered to the substrate layer and a nonhandleable, non-self-supporting protective cover layer which is self-adhering to the fine fiber layer and has a very smooth outer surface. Suitable cover layer materials include polystyrene and polycarbonate fibers.
Inventors
- 👤 Marty A. Barris
- 👤 Richard L. Zelinka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:01
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/0007; D01D5/0061; D01D5/0076; D01D5/0084; B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; D01D5/18; D04; D04H; D04H1/00; D04H1/40; D04H1/54; D04H1/56; B01D2239/00; B01D2239/10
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
67 words
A handleable, self-supporting and durable multilayered microfiltration medium having a high particle capture efficiency and minimal flow restriction comprising: a self-supporting porous substrate layer having a fine fiber filtration layer deposited on and adhering thereto; and a porous nonhandleable fiber cover layer deposited on and adhering to said filtration layer, said cover layer being about one to two fibers thick and completely self-adhering to said filtration layer.
Claim 2
Dependent Claim
67 words
A handleable, self-supporting and durable multilayered microfiltration medium having a high particle capture efficiency and minimal flow restriction comprising: a self-supporting porous substrate layer having a fine fiber filtration layer deposited on and adhering thereto; and a porous nonhandleable fiber cover layer deposited on and adhering to said filtration layer, said cover layer being about one to two fibers thick and completely self-adhering to said filtration layer.
Claim 3
Dependent Claim
18 words
A multilayered microfiltration medium in accordance with claim 1 wherein said filtration layer fibers are formed from polyacrylonitrile.
Claim 4
Dependent Claim
19 words
A multilayered microfiltration medium in accordance with claim 1 wherein said filtration layer fibers are formed from polyvinylidene chloride.
Claim 5
Dependent Claim
18 words
A multilayered microfiltration medium according to claim 1 wherein said cover layer has a very smooth outer surface.
Claim 6
Dependent Claim
46 words
A multilayered microfiltration medium in accordance with claim 1 wherein said filtration layer fibers have a diameter less than 0.5 micron and said filtration layer has a thickness from about 0.2 to 80 microns and a basis weight from about 0.6 to 240 micrograms/cm 2 .
Claim 7
Dependent Claim
48 words
A multilayered microfiltration medium in accordance with claim 1 wherein said cover layer fibers have a diameter from about 5 to 30 microns and said cover layer has a thickness from about 5 to 60 microns and a basis weight from about 0.04 to 0.5 milligrams/cm 2 .
Claim 8
Dependent Claim
37 words
A multilayered microfiltration medium according to claim 1 wherein said cover layer increases said capture efficiency of said medium less than about 0.1% and increases said flow restriction of said medium less than 0.001 inches of water.
Claim 9
Dependent Claim
18 words
A multilayered microfiltration medium in accordance with claim 1 wherein said cover layer fibers are formed from polycarbonate.
Claim 10
Dependent Claim
18 words
A multilayered microfiltration medium in accordance with claim 1 wherein said cover layer fibers are formed from polystyrene.
Claim 11
Dependent Claim
153 words
A handleable, self-supporting and durable multilayered microfiltration medium having a high particle capture efficiency and minimal flow restriction comprising: a self-supporting highly permeable substrate layer, said substrate layer providing a support structure for said medium and having a low relative efficiency and low relative flow restriction; a thin efficiency layer of fine fibers having a diameter less than about 0.5 micron, said efficiency layer deposited on and adhering to said substrate layer and having a thickness from about 0.2 to 80 microns and a basis weight from about 0.6 to 240 micrograms/cm 2 ; and a nonhandleable, non-self-supporting protective cover layer of fibers having a diameter from about 5 to 30 microns, said cover layer formed and deposited on said efficiency layer and having a thickness from about 5 to 60 microns and a basis weight from about 0.04 to 0.5 millidrams/cm 2 , said cover layer being self-adhering to said efficiency layer.
Claim 12
Dependent Claim
153 words
A handleable, self-supporting and durable multilayered microfiltration medium having a high particle capture efficiency and minimal flow restriction comprising: a self-supporting highly permeable substrate layer, said substrate layer providing a support structure for said medium and having a low relative efficiency and low relative flow restriction; a thin efficiency layer of fine fibers having a diameter less than about 0.5 micron, said efficiency layer deposited on and adhering to said substrate layer and having a thickness from about 0.2 to 80 microns and a basis weight from about 0.6 to 240 micrograms/cm 2 ; and a nonhandleable, non-self-supporting protective cover layer of fibers having a diameter from about 5 to 30 microns, said cover layer formed and deposited on said efficiency layer and having a thickness from about 5 to 60 microns and a basis weight from about 0.04 to 0.5 millidrams/cm 2 , said cover layer being self-adhering to said efficiency layer.
Claim 13
Dependent Claim
17 words
A multilayered microfiltration medium according to claim 10 wherein said cover layer has a smooth outer surface.
Claim 14
Dependent Claim
38 words
A multilayered microfiltration medium according to claim 10 wherein said cover layer increases said capture efficiency of said medium less than about 0.1% and increases said flow restriction of said medium less than about 0.001 inches of water.
Claim 15
Dependent Claim
18 words
A multilayered microfiltration medium in accordance with claim 10 wherein said efficiency layer fibers are formed from polyacrylonitrile.
Claim 16
Dependent Claim
19 words
A multilayered microfiltration medium in accordance with claim 10 wherein said efficiency layer fibers are formed from polyvinylidene chloride.
Claim 17
Dependent Claim
18 words
A multilayered microfiltration medium in accordance with claim 10 wherein said cover layer fibers are formed from polycarbonate.
Claim 18
Dependent Claim
18 words
A multilayered microfiltration medium in accordance with claim 10 wherein said cover layer fibers are formed from polystyrene.
Claim 19
Dependent Claim
217 words
A handleable, self-supporting and durable multilayered microfiltration medium having a high particle capture efficiency and minimal flow restriction comprising: a self-supporting highly permeable substrate layer, said substrate layer providing support structure for said medium and having a low relative efficiency and low relative flow restriction, said substrate layer contributing no more than about 20% of the medium's total efficiency and flow restriction; a thin, non-self-supporting efficiency layer of fine fibers having a diameter less than 0.5 micron, said efficiency layer deposited on and adhering to said substrate layer and having a thickness from about 0.2 to 80 microns and a basis weight from about 0.6 to 240 micrograms/cm 2 ; and a non-handleable, non-self-supporting protective cover layer of fibers having a diameter from about 5 to 30 microns, said cover layer having a thickness from about 5 to 60 microns, a basis weight from about 0.04 to 0.5 milligrams/cm 2 and a volume fraction of solids of less than 10%, said cover layer formed and deposited on said efficiency layer, said cover layer being nonlaminated and self-adhering to said efficiency layer and having a very smooth outer surface, said cover layer increasing said capture efficiency of said medium less than about 0.1% and increasing said flow restriction of said medium less than about 0.001 inches of water.
Claim 20
Dependent Claim
217 words
A handleable, self-supporting and durable multilayered microfiltration medium having a high particle capture efficiency and minimal flow restriction comprising: a self-supporting highly permeable substrate layer, said substrate layer providing support structure for said medium and having a low relative efficiency and low relative flow restriction, said substrate layer contributing no more than about 20% of the medium's total efficiency and flow restriction; a thin, non-self-supporting efficiency layer of fine fibers having a diameter less than 0.5 micron, said efficiency layer deposited on and adhering to said substrate layer and having a thickness from about 0.2 to 80 microns and a basis weight from about 0.6 to 240 micrograms/cm 2 ; and a non-handleable, non-self-supporting protective cover layer of fibers having a diameter from about 5 to 30 microns, said cover layer having a thickness from about 5 to 60 microns, a basis weight from about 0.04 to 0.5 milligrams/cm 2 and a volume fraction of solids of less than 10%, said cover layer formed and deposited on said efficiency layer, said cover layer being nonlaminated and self-adhering to said efficiency layer and having a very smooth outer surface, said cover layer increasing said capture efficiency of said medium less than about 0.1% and increasing said flow restriction of said medium less than about 0.001 inches of water.
Claim 21
Dependent Claim
18 words
A multilayered microfiltration medium in accordance with claim 17 wherein said efficiency layer fibers are formed from polyacrylonitrile.
Claim 22
Dependent Claim
19 words
A multilayered microfiltration medium in accordance with claim 17 wherein said efficiency layer fibers are formed from polyvinylidene chloride.
Claim 23
Dependent Claim
18 words
A multilayered microfiltration medium in accordance with claim 18 wherein said cover layer fibers are formed from polycarbonate.
Claim 24
Dependent Claim
18 words
A multilayered microfiltration medium in accordance with claim 18 wherein said cover layer fibers are formed from polystyrene.
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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) | 1990-03-16 | 1990-09-15 | 1991-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-16 | 1994-09-15 | 1995-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-16 | 1998-09-15 | 1999-03-17 | $7700.00 | Window Closed / Lapsed |