US4069026A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter made of electrostatically spun fibres
Assignee: Bayer AG
•
Filing: 1973-11-15
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Granted: 1978-01-17
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Expires: 1993-11-15
Abstract
Abstract In a process for the production of fibre filters, the fibre material is sprayed electrostatically from the liquid state and deposited as a fibre fleece on a conductive support. The starting materials used are solutions of high polymers in readily volatile solvents. The charged filters obtained have substantially improved properties.
Inventors
- 👤 Walter Simm
- 👤 Claus Gosling
- 👤 Richard Bonart
- 👤 Bela VON Falkai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:07
CPC Classifications
D; D04; D04H; D04H13/00; B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; B03; B03C; B03C3/00; B03C3/28; B01D2239/00; B01D2239/10
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
102 words
A fibre filter comprising a fibre fleece having an electrical charge produced by electrostatically spraying a solution of a polymer in a volatile solvent having a conductivity of 10 -9 Ohm -1 cm -1 to 10 -4 Ohm -1 cm -1 between an electrode wetted by the solution and a conductive support for spraying of the solution, evaporation of the solvent, and collection of the polymer as the fibre fleece on the support, the polymer being polycarbonate and the fibres of the fibre fleece having a porous surface structure, and a gas permeable support combined with the fibre fleece as support therefor.
Claim 2
Dependent Claim
102 words
A fibre filter comprising a fibre fleece having an electrical charge produced by electrostatically spraying a solution of a polymer in a volatile solvent having a conductivity of 10 -9 Ohm -1 cm -1 to 10 -4 Ohm -1 cm -1 between an electrode wetted by the solution and a conductive support for spraying of the solution, evaporation of the solvent, and collection of the polymer as the fibre fleece on the support, the polymer being polycarbonate and the fibres of the fibre fleece having a porous surface structure, and a gas permeable support combined with the fibre fleece as support therefor.
Claim 3
Dependent Claim
27 words
Fibre filter according to claim 1, wherein the gas permeable support is a fabric or fibre fleece combined with the first mentioned fibre fleece as a laminate.
Claim 4
Dependent Claim
17 words
Fibre filter according to claim 1, the fibre fleece and support being mounted in a frame therefor.
Claim 5
Dependent Claim
19 words
Fibre filter according to claim 1, wherein the gas permeable support comprises coarse fibres incorporated in the fibre fleece.
Claim 6
Dependent Claim
24 words
Fibre filter according to claim 1, comprising several layers of fibre fleeces each produced as aforesaid, said layers, respectively having positive and negative charges.
Claim 7
Dependent Claim
23 words
Fibre filter according to claim 1, comprising several layers of fibre fleeces, each produced as aforesaid and from a solution of different conductivity.
Claim 8
Dependent Claim
20 words
Fibre filter according to claim 1, each side of the fibre fleece being covered with a gas permeable support layer.
Claim 9
Dependent Claim
22 words
Fibre filter according to claim 1, the fibre fleece including fibres of thickness less than 1 μm and having a porous surface.
Claim 10
Dependent Claim
12 words
Fibre filter according to claim 1, said volatile solvent being methylene chloride.
Claim 11
Dependent Claim
12 words
Fibre filter according to claim 1, said volatile solvent being methylene chloride.
Claim 12
Dependent Claim
32 words
Fibre fleece according to claim 1, wherein the electrode is continuously drawn through the solution of the polymer for providing said wet electrode and the solution is electrostatically sprayed from the electrode.
Claim 13
Dependent Claim
25 words
Process of filtering dust particles from a gas which comprises passing the gas containing the dust particles through a fibre filter according to claim 1.
References Cited (Backward Citations)
US2138874A
Cited
US2810426A
Cited
US2795290A
Cited
US2888095A
Cited
US3400520A
Cited
US3461882A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-16 | 1981-07-18 | 1982-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-16 | 1985-07-18 | 1986-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-16 | 1989-07-18 | 1990-01-17 | $7700.00 | Window Closed / Lapsed |