Claims
- 1. An article comprising several layers of fibre fleeces each produced by electrostatically spraying a solution having a conductivity of 10.sup.-9 Ohm.sup.-1 cm.sup.-1 to 10.sup.-4 Ohm.sup.-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, 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.
- 2. An article according to claim 1, wherein the fibres of the fibre fleeces have a porous surface structure.
- 3. An article according to claim 1, wherein each layer is produced from a solution of different conductivity.
- 4. An article according to claim 1, wherein the fibre fleeces include fibres of thickness less than 1 .mu.m.
- 5. Process of producing a fleece of polymeric fibres which comprises electrostatically spraying a solution having a conductivity of .sup.-9 Ohm.sup.-1 cm.sup.-1 to 10.sup.-4 Ohm.sup.-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.
- 6. 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.
- 7. Process according to claim 5, further comprising providing the fibre fleece including fibres of thickness less than 1 .mu.m.
- 8. 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.
- 9. 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.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2032072 |
Jun 1970 |
DEX |
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Parent Case Info
This application is a continuation-in-part of application Ser. No. 416,316, filed Nov. 15, 1973, now U.S. Pat. No. 4,069,026, and which is a continuation-in-part of Ser. No. 155,189, filed June 21, 1971 now abandoned. The specification herein duplicates the specificiation in said Ser. No. 155,189.
US Referenced Citations (8)
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
416316 |
Nov 1973 |
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Parent |
155189 |
Jun 1971 |
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