Electroblowing fiber spinning process

1. A fiber spinning process comprising:

providing an uncharged, electrically conductive polymer-containing liquid stream to a spinneret;

issuing said polymer-containing liquid stream in combination with a forwarding gas in a direction from at least one spinning nozzle in said spinneret;

passing said polymer-containing liquid stream through an ion flow formed by corona discharge to impart electrical charge to the liquid stream;

forming fine polymer fibers of said polymer; and

collecting said fine polymer fibers;

wherein said polymer-containing liquid stream further comprises a solvent for said polymer, and

wherein said ion flow is formed between differentially charged point- and target-electrodes, and the electrodes are disposed a variable die-to-electrode distance (DED) from the spinning nozzle that is short enough to impart electrical charge to the polymer-containing liquid stream prior to fiber formation.

2. The fiber spinning process of claim 1 , wherein said polymer-containing liquid stream comprises molten polymer.

3. The fiber spinning process of claim 1 , wherein said polymer-containing liquid stream has a conductivity of at least about 10 −12 Siemens/m.

4. The fiber spinning process of claim 1 , wherein said point-electrode is negatively charged and said target-electrode is grounded.

5. The fiber spinning process of claim 1 , wherein said point-electrode is positively charged and said target-electrode is grounded.

6. The fiber spinning process of claim 1 , wherein said point-and target-electrodes are oppositely charged.

7. The fiber spinning process of claim 1 , wherein the charge differential between said point- and target-electrodes is at least 1 kV, but less than that required to cause arcing between the electrodes.

8. The fiber spinning process of claim 1 , wherein said polymer-containing liquid stream is passed through a drift zone established between said point- and target-electrodes.

9. The fiber spinning process of claim 1 , wherein said fine polymer fibers have average effective diameters of less than about 1 micrometer.

10. The fiber spinning process of claim 9 , wherein said fine polymer fibers have average effective diameters of less than about 0.5 micrometer.

11. The fiber spinning process of claim 1 , wherein said fine polymer fibers are collected as a fibrous web having substantially no residual electrical charge.

12. The fiber spinning process of claim 1 , wherein said ion flow is transverse to the direction of the polymer-containing liquid stream.

13. A fiber spinning process comprising:

providing an uncharged, electrically conductive polymer solution to a spinneret;

issuing said polymer solution as a stream in combination with a forwarding gas in a direction from at least one spinning nozzle in said spinneret;

passing said stream through an ion flow formed by corona discharge, said ion flow being transverse to the direction of the stream, to impart electrical charge to said stream;

forming fine polymer fibers having average effective diameters of less than about 0.5 micrometer from said stream; and

collecting said fine polymer fibers as a fibrous web having substantially no residual electrical charge:

wherein said polymer-containing liquid stream further comprises a solvent for said polymer, and

wherein said ion flow is formed between differentially charged point- and target-electrodes, and the electrodes are disposed a variable die-to-electrode distance (DED) from the spinning nozzle that is short enough to impart electrical charge to the polymer-containing liquid stream prior to fiber formation.