Abstract: A method and apparatus provided for the production of fine fibers by electrospinning fibers by applying an electrical field between a primary electrode and a counter electrode (5) spaced apart from the primary electrode and extending generally parallel thereto wherein at least an operative surface of the primary electrode is coated with a polymer solution (3) and an electric field of sufficient magnitude is generated between the primary electrode and counter electrode to cause the formation of fine fibers (9) in the space between the electrodes. The operative surface of the primary electrode that is coated with polymer solution is made up of appropriate portions of the surfaces of a multitude of operatively semi-submerged, loose (unattached) elements (1, 11, 17, 21) supported on the bottom of a trough (2) or tray or another support member or members (12, 18, 22).

Abstract: A process is provided for producing fibers which includes forming a plurality of bubbles on the surface of a fiber spinning solution, applying a voltage between the solution and a counter-electrode spaced apart therefrom to cause jets to extend from the bubbles to the counter-electrode, and treating the solution with a surfactant to stabilize the bubbles.

Abstract: A method and apparatus provided for the production of fine fibres by electrospinning fibres by applying an electrical field between a primary electrode and a counter electrode (5) spaced apart from the primary electrode and extending generally parallel thereto wherein at least an operative surface of the primary electrode is coated with a polymer solution (3) and an electric field of sufficient magnitude is generated between the primary electrode and counter electrode to cause the formation of fine fibres (9) in the space between the electrodes. The operative surface of the primary electrode that is coated with polymer solution is made up of appropriate portions of the surfaces of a multitude of operatively semi-submerged, loose (unattached) elements (1, 11, 17, 21) supported on the bottom of a trough (2) or tray or another support member or members (12, 18, 22).

Abstract: A method and apparatus provided for the production of fine fibers by electrospinning fibers by applying an electrical field between a primary electrode and a counter electrode (5) spaced apart from the primary electrode and extending generally parallel thereto wherein at least an operative surface of the primary electrode is coated with a polymer solution (3) and an electric field of sufficient magnitude is generated between the primary electrode and counter electrode to cause the formation of fine fibers (9) in the space between the electrodes. The operative surface of the primary electrode that is coated with polymer solution is made up of appropriate portions of the surfaces of a multitude of operatively semi-submerged, loose (unattached) elements (1, 11, 17, 21) supported on the bottom of a trough (2) or tray or another support member or members (12, 18, 22).

Abstract: A yarn spun from a plurality of nano-fibers is provided and is characterized in that at least some of the nano-fibers are folded with the folds occurring at predeterminable distances which are integer multiples of a specific spacing. The folds result from spinning the nano-fibers onto a plurality of moving conductive strips which are inclined to their direction of movement. A process and apparatus for producing such yarn is also provided.

Abstract: A yarn spun from a plurality of nano-fibres is provided and is characterized in that at least some of the nano-fibres are folded with the folds occurring at predeterminable distances which are integer multiples of a specific spacing. The folds result from spinning the nano-fibres onto a plurality of moving conductive strips which are inclined to their direction of movement. A process and apparatus for producing such yarn is also provided.

Abstract: A method and apparatus provided for the production of fine fibres by electrospinning fibres by applying an electrical field between a primary electrode and a counter electrode (5) spaced apart from the primary electrode and extending generally parallel thereto wherein at least an operative surface of the primary electrode is coated with a polymer solution (3) and an electric field of sufficient magnitude is generated between the primary electrode and counter electrode to cause the formation of fine fibres (9) in the space between the electrodes. The operative surface of the primary electrode that is coated with polymer solution is made up of appropriate portions of the surfaces of a multitude of operatively semi-submerged, loose (unattached) elements (1, 11, 17, 21) supported on the bottom of a trough (2) or tray or another support member or members (12, 18, 22).

Abstract: A process is provided for producing fibers which includes forming a plurality of bubbles on the surface of a fiber spinning solution, applying a voltage between the solution and a counter-electrode spaced apart therefrom to cause jets to extend from the bubbles to the counter-electrode, and treating the solution with a surfactant to stabilize the bubbles.

Abstract: A preservative gas generating device includes a carrier sheet and a layer of a matrix forming material having a preservative gas generating compound dispersed therein. The layer of matrix forming material permits the generation of a preservative gas by the preservative gas generating compound and to permit the gas to permeate out of the matrix formed by the material. The matrix forming material adheres to the carrier sheet in the form of a layer covering an area of the carrier sheet and forms at least one discrete zone, with a peripheral area of the carrier sheet surrounding the discrete zone(s) being substantially free of the matrix forming material. A cover sheet is secured to said peripheral area to enclose the layer of matrix forming material between the carrier sheet and the cover sheet. At least one of the carrier sheet and the cover sheet are permeable to said preservative gas.

Abstract: A polyurethane resin consists of a reaction product of a phosphated polyol, a polyisocyanate and optionally a stabilizing monomer having a salt-forming group, for example, 2,2-dimethyolol propionic acid. The phosphated polyol may be a hydroxyl-terminated, phosphated polyester polyol which is a reaction product of a carboxylic acid, a polyol and a phosphate monomer. The phosphate monomer may be 2-phosphonobutane-1,2,4-tricarboxylic acid. The invention provides aqueous dispersions of phosphated polyurethane resins which are particularly suitable as metal primers for metals such as galvanised steel. The metal primers have improved adhesion under agressive enviroments.

Abstract: A method of producing a secondary metabolites comprises providing a porous substratum which has a biofilm of micro-organism attached thereto, and causing a nutrient solution to flow through the substratum, at a rate which is sufficiently low for a nutrient gradient to be established across the biofilm, such that the nutrient concentration at a high level along the gradient is sufficiently high to support primary growth of the micro-organism, and the nutrient concentration at low level along the gradient being sufficiently low to induce secondary growth of the micro-organism, thereby to produce secondary metabolite. The substrate is in the form of a hollow fibre membrane having a relatively thin, porous skin on the inside, and a relatively thick, finger-like, externally unskinned void structure radiating outwardly from the skin.

Abstract: A method of making a hollow fiber membrane comprises extruding a membrane-forming polymer solution through the annulus of a tube-in-orifice spinneret (12) to form a nascent hollow membrane (32), there being a lumen coagulant in the lumen of the nascent membrane, and the outside of the nascent membrane being contacted with an external coagulant (34). The external coagulant has a solvent content which is such that, at the interface between the nascent membrane and the external coagulant, liquid--liquid phase separation rather than gelation is thermodynamically the favored process, and the membrane is then subjected to a vapor-phase non-solvent environment to induce precipitation of the phase-separated polymer.