US3594993A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous, bonded and impregnated, nonwoven filter sheet structure
Assignee: Dexter Corp
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Filing: 1966-11-14
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Granted: 1971-07-27
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Expires: 1986-11-14
Abstract
Abstract High efficiency particulate air filters having unusual resistance to high temperatures, hydrolytic environments and acidic conditions may be formed from an improved porous inorganic sheet structure comprised essentially of microglass fibers and a polyphenylene ether binder. Such sheets show no substantial decrease in strength characteristics after exposure to 300* C. for 10 minutes, a water repellency of about 30 inches (MIL-STD282) or more and resistance to attack by even hydrofluoric acid.
Inventors
- 👤 William T Heyse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:07
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2003; B01D39/2017; B01D39/2024; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/298; Y10T428/31504; Y10T428/31652; Y10T442/00; Y10T442/60; Y10T442/608; Y10T442/614; Y10T442/623
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
45 words
A sheet structure as set forth in claim 1 wherein the inorganic fibers are predominantly microfibers having an average diameter of about 0.05 to 4.0 microns, the sheet exhibiting a water repellency according to MIL-STD-282 exceeding a hydrostatic head of 10 inches prior to penetration.
Claim 2
Dependent Claim
18 words
A sheet structure as set forth in claim 1 wherein the binder is a thermoplastic polyphenylene ether resin.
Claim 3
Dependent Claim
30 words
An inorganic sheet structure as set forth in claim 2 wherein the binder consists of 2 to 8 percent by weight based on the total weight of the sheet structure.
Claim 4
Dependent Claim
65 words
The sheet structure of claim 4 wherein the inorganic fibers are glass and consist predominantly of fibers having an average diameter of 0.05 to 4.0 microns, said sheet having tensile breaking strengths greater than 2.5 pounds per inch in the machine direction and greater than 2.0 pounds per inch in the cross direction both before and after exposure to a temperature of about 300* C.
Claim 5
Dependent Claim
36 words
The porous sheet structure of claim 3 particularly well suited as a filter medium wherein the polyphenylene ether resin binder consists of polyxylenol and constitutes about 3 to 5 percent by weight of the sheet structure.
Claim 6
Dependent Claim
42 words
The sheet structure of claim 6 wherein about 80 percent by weight of the inorganic fibers are glass having an average diameter less than 5 microns and about 20 percent by weight are reinforcing fibers of about 9 micron diameter or larger.
Claim 7
Dependent Claim
19 words
The sheet structure of claim 3 particularly well suited as a separator wherein the inorganic fibers are predominantly asbestos.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |