Patent US4143196A successfully refreshed from Google Patents.
US4143196A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fibre fleece of electrostatically spun fibres and methods of making same
Assignee: Bayer AG
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Filing: 1977-07-07
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Granted: 1979-03-06
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Expires: 1997-07-07
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 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 10:58
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/0007; B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; D04; D04H; D04H13/00; B01D2239/00; B01D2239/10; Y; Y10; Y10S; Y10S428/00; Y10S428/903; Y10S55/00; Y10S55/39; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/249921; Y10T428/249953; Y10T428/249981; Y10T428/26; Y10T428/29; Y10T428/2913; Y10T428/2973; Y10T428/2975; Y10T428/2978; Y10T428/31; Y10T442/00; Y10T442/50; Y10T442/56; Y10T442/60; Y10T442/674
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
94 words
An article comprising several layers of fibre fleeces each produced by electrostatically spraying a solution having a conductivity of 10 -9 Ohm -1 cm -1 to 10 -4 Ohm -1 cm -1 of a polymer in a volatile solvent 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 fibers of the fleece having a porous surface structure, said layers, respectively, having positive and negative charges.
Claim 2
Dependent Claim
94 words
An article comprising several layers of fibre fleeces each produced by electrostatically spraying a solution having a conductivity of 10 -9 Ohm -1 cm -1 to 10 -4 Ohm -1 cm -1 of a polymer in a volatile solvent 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 fibers of the fleece having a porous surface structure, said layers, respectively, having positive and negative charges.
Claim 3
Dependent Claim
18 words
An article according to claim 1, wherein the fibres of the fibre fleeces have a porous surface structure.
Claim 4
Dependent Claim
17 words
An article according to claim 1, wherein each layer is produced from a solution of different conductivity.
Claim 5
Dependent Claim
18 words
An article according to claim 1, wherein the fibre fleeces include fibres of thickness less than 1 μm.
Claim 6
Dependent Claim
110 words
Process of producing a fleece of polymeric fibres which comprises electrostatically spraying a solution having a conductivity of -9 Ohm -1 cm -1 to 10 -4 Ohm -1 cm.sup. -1 of a polymer in a volatile solvent between an electrode wetted by the solution and a conductive support for spraying of the solution, evaporation of the solvent, collection of the polymer as the fibre fleece on the support, the polymer being polycarbonate and the fibres of the fleece having a porous surface structure, impressing charges of opposite polarity on the electrode and the support and alternating the polarity to provide the fleece composed of layers with positive and negative charges.
Claim 7
Dependent Claim
110 words
Process of producing a fleece of polymeric fibres which comprises electrostatically spraying a solution having a conductivity of -9 Ohm -1 cm -1 to 10 -4 Ohm -1 cm.sup. -1 of a polymer in a volatile solvent between an electrode wetted by the solution and a conductive support for spraying of the solution, evaporation of the solvent, collection of the polymer as the fibre fleece on the support, the polymer being polycarbonate and the fibres of the fleece having a porous surface structure, impressing charges of opposite polarity on the electrode and the support and alternating the polarity to provide the fleece composed of layers with positive and negative charges.
Claim 8
Dependent Claim
25 words
Process according to claim 5, further comprising electrostatically spraying solutions of different conductivity onto the support to incorporate coarse and fine fibres into the fleece.
Claim 9
Dependent Claim
19 words
Process according to claim 5, further comprising providing the fibre fleece including fibres of thickness less than 1 μm.
Claim 10
Dependent Claim
27 words
Process according to claim 5, further comprising providing a gas permeable support layer on the conductive support and collecting the fibres on the gas permeable support layer.
Claim 11
Dependent Claim
43 words
Process according to claim 8, wherein the solution is maintained in a vessel therefor and said electrode is a rotating annular electrode only partially immersed in the solution, the solution being sprayed from that part of the electrode not immersed in the solution.
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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) | 1982-03-05 | 1982-09-04 | 1983-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-05 | 1986-09-04 | 1987-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-05 | 1990-09-04 | 1991-03-06 | $7700.00 | Window Closed / Lapsed |