Abstract: An audio noise calibration circuit is provided comprising: a speaker, the speaker including a driver input; a switch having a first terminal, a second terminal, and an output, and wherein the switch is adapted to be responsive to a switching signal having at least a first switching state and a second switching state such that the first terminal of the switch is connected to the output of the switch when the switching signal is in the first switching state such that there is electrical connectivity between the first terminal and the output, and the second terminal of the switch is connected to the output of the switch when the switching signal is in the second switching state such that there is electrical connectivity between the second terminal and the output, and further wherein the output of the switch is connected to the driver input of the speaker; and an audio processing unit adapted to generate the switching signal such that when in the first switching state, an audio signal generated by the audio proce

Abstract: Disclosed herein is a method for preparing a cellulose-based film from raw material pulp, the method including the steps of: preparing a dope from a composition comprising 5-15 wt % of a pulp having an alpha-cellulose content of more than 90% and 85-95 wt % of an aqueous N-methylmorpholine-N-oxide solution; extruding the dope from a die onto a running support; casting the extrudate to form a sheet-shaped material; washing the cast sheet with water to remove N-methylmorpholine-N-oxide therefrom; and drying the washed sheet. The method enables the cellulose-based film to be prepared from environmentally friendly wood pulp through an environmentally friendly process.

Abstract: The present invention provides a method for the production of a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) asymmetric hollow fiber membrane. The invention comprises preparing a dope solution of PVDF-HFP with an additive of lithium chloride or glycerol dissolved in a solvent such as N-methylpyrollidone (NMP). The dope solution is spun to form a PVDF-HFP asymmetric hollow fiber membrane.

Abstract: A method of producing a non-lofted fiber veil of an orientable polymer for the production of insulation, e.g. thermal, for blown-in applications, having X, Y and Z vector directions of the fibers comprising, melt blowing the polymer to form molten fibers, having molecules oriented along the length of the fibers, the X vector direction, placing the fibers on a roller spinning at a rate to provide additional orientation of the molecules of the fibers, displacing some said fibers into the Y vector direction, and cooling the fibers while on the roller to form the non-lofted fiber veil. Also included is the product of the method, a blown in insulation, intermediate products, an apparatus and a method of producing a product for blown-in installation.

Abstract: An improved process for the preparation of a cellulose solution for spinning of fibres, filaments or films therefrom comprising the steps of: a) activating cellulose in a mixture containing said cellulose, tertiary amine oxide solvent and water for a period sufficient to allow a swelling of the cellulose by introduction therein of water present in said mixtures, the temperature of said activation step and concentration of solvent being such that the solvent is not converted into its monohydrate state during the step of activation; b) the cellulose mixture being subjected to the steps of dissolution of cellulose in the solvent by heating for removal of water so as to convert the solvent into at least its monohydrate form so as to cause a dissolution.

Abstract: The present invention provides a seamless tubular film on a cellulose base, being produced by extruding an aqueous cellulose N-methyl-morpholine-N-oxide spinning solution. The maximum degree of roughness Rmax is from greater than 0.1 &mgr;m to 0.5 &mgr;m and an average degree of roughness Rm is from 0.005 to 0.014 &mgr;m. On the surface of the tubular film is formed in contact with an electrolyte an electrokinetic potential, the size of which depends on the pH value of the electrolyte.

Abstract: Disclosed is a method of sizing nonderivatized extruded cellulosic tubes by the use of a mandrel structure that includes a hollow sizing portion having openings which gather gas bubbles that may evolve at the interface between the extruded tube and the sizing portion and allows the gas to pass into the hollow interior of the mandrel. The mandrel contains a sizing portion larger than the extruded tube, which allows for improved sizing of nonderivatized extruded tubes that are used as casings.

Abstract: Disclosed is a mandrel structure for extruding a tube composed of a non derivatized cellulose. The mandrel includes a hollow sizing portion having openings which gather gas bubbles that may evolve at the interface between the extruded tube and the sizing portion and allows the gas to pass into the hollow interior of the mandrel.

Abstract: The present invention that also possesses provides a method for producing a seamless tubular film based on cellulose comprising extruding an aqueous cellulose-N-methyl-morpholine-N-oxide (NMMO) spinning solution through an annular die in a spinning bath, wherein the spinning solution forms the tubular film. The film is laterally drawn in an air gap between the annular die and the spinning bath by stabilizing air pressure in the tubular film. The level of hydrostatic pressure from an inner spinning solution formed inside the tubular film extends above the spinning bath, the inner spinning solution comprising an aqueous NMMO solution that supports and intensifies said lateral drawing. The tubular film that has been expanded by the lateral drawing process is passes by a turning point in the spinning bath, and directed out of the spinning bath.

Abstract: A method and apparatus is disclosed for lacing an extruded tube of a non derivatized cellulose through an S-wrap to collapse the tube to a flat width. The lacing to form the S-wrap is accomplished without slowing the extrusion speed. At the start of the extrusion operation, the extrusion path leads between a pair of horizontally lacing members. After the leading edge of the extruded tube has passed downwardly through the space between the lacing members, the members are rotated as a unit to bring them into contact with opposite sides of the extruded tube. This collapses the and creates the S-wrap.

Abstract: A method and apparatus for controlling the diameter of a clear extruded molten tube wherein the extruded tube contains a volume of a clear liquid and the level of the liquid is indicative of the tube diameter so the level rises as the tube diameter decreases. A light beam passing through the tube is refracted from a straight line path when the liquid level rises above the level of the beam. The refracting of the beam in turn triggers the introduction of air into the extruded tube to increase the diameter of the extruded, molten tube.

Abstract: The invention is directed to a method of manufacturing oriented cellulose films by spinning non-derivated cellulose dissolved in amino oxides into a precipitating bath. The cellulose solution is extruded downward through a film-blowing nozzle and an external air gap into the precipitating bath. The spun cellulose film can be inflated after exiting the film-blowing nozzle.

Abstract: A seamless cellulose-based tubular film is produced by extrusion of an aqueous cellulose-N-methylmorpholine N-oxide solution.

Abstract: Formulation polymer dopes and development of processes for preparing asymmetric polyethersulfone hollow fiber membranes for gas separation are provided. Polyethersulfone hollow fiber membranes which exhibit improved gas permeability and selectivity have been produced from a formulated polymer dope containing N-methyl-2-pyrrolidone (NMP) and suitable nonsolvent-additives (NSA). The nonsolvent-additives are water and the mixture of ethanol and water. The dopes were tailored to be close to the point of phase separation, and have moderate polymer concentration with moderate viscosity. The hollow fibers were spun by the dry-wet phase inversion processes using water as both the internal and external coagulant. The dried hollow fibers are then coated with silicone rubber, a highly permeable material and the coated hollow fiber membranes exhibit excellent permeability and selectivity compared to those of the state-of-the-art polyethersulfone membranes.

Abstract: A process for forming ultrathin dense-layer asymmetric hollow fiber membranes with a dense layer of less than 500 .ANG. from a binary solution system comprising a polymer and a solvent. In this process, the spinning polymeric solution has a high viscosity and exhibits chain entanglement at the spinning temperature. The solubility parameter difference between the bore fluid and the spinning dope is less than 2.5 (cal/cm.sup.3).sup.0.5 and the volume ratio of bore-fluid flow rate to the dope flow rate is between 0.45 to 0.75. The dope is wet-spun into hollow fibers using water as external coagulant. The ultrathin dense-layer asymmetric hollow fiber membranes are suitable for air and other gas separations.

Abstract: A process for producing a hollow fiber membrane, a hollow fiber membrane, and a dialyzer of hollow fiber membrane type is provided. The hollow fiber membrane is highly biocompatible, and the production process is quite simple and inexpensive. In the process of the invention, the hollow fiber membrane is produced in a system wherein a polymer-containing spinning solution is extruded from a tube-in-tube type orifice of a spinner in a coagulation solution to form the hollow fiber membrane. The polymer-containing spinning solution is extruded from the outer tube of the orifice to form a cylindrical filament having an inner bore and a core solution is ejected from the inner tube of the orifice into the inner bore of the filament for coagulation of the filament. The filament is directly extruded into the coagulation solution or extruded into air and then drawn to the coagulation solution.

Abstract: Disclosed is a method of extruding a solution of cellulose and an amine oxide cellulose solvent as a tube about a sizing mandrel which diametrically stretches the extruded tube. An aqueous poly(ethylene oxide) solution is introduced into the interior of the extruded tube to facilitate passage of the tube over the sizing mandrel and to extract the amine oxide cellulose solvent from the tube. After such extraction, the aqueous poly(ethylene oxide) solution containing the extracted amine oxide cellulose solvent is contacted with an anion exchanger to remove the poly(ethylene oxide) so the amine oxide cellulose solvent can be recovered.

Abstract: Improved anisotropic fluid separation membranes are prepared from blends of polymers with surface energy differences. The membranes are formulated by processes wherein low surface energy polymer with desirable fluid separation and permeation characteristics is preferentially concentrated in the surface discriminating layer of the membrane.

Abstract: The present invention relates to a method for the production of a fiber-reinforced cellulose tube by continuous coating of a fibrous non-woven fabric with an alkaline viscose solution which is neutralized by means of an acid-containing precipitating liquid and is converted into regenerated cellulose, wherein on the path between viscose coating and immersion in the precipitating bath, aqueous, acid-containing precipitating agents are caused to act upon the fresh viscose tube within the tube for the purpose of stiffening and regeneration to form regenerated cellulose, the process being begun with the application of the precipitating liquid directly after conclusion of the embedding of fiber in viscose and the precipitating liquid being guided together with the tube with the aid of optionally fixed internal devices which are designed in such a way that they support the tube that has had precipitating bath applied to it and in the process maintain it in rounded shape, that the length of the inner preliminary prec

Abstract: The tubular extrusion of a thermoplastic nonderivatized cellulose solution about a mandrel and through a long air gap in excess of 304 mm is facilitated by use of a mandrel which is extensible from the extrusion die. On extrusion start-up, the mandrel extends a short length from the die. For steady-state operation, the mandrel is extended its full length from the die. Also disclosed is a mandrel structure to facilitate the introduction of a nonsolvent liquid into the interior of the extruded tube at a high location on start-up of extrusion and at a lower location during steady-state operation.

Abstract: The tubular extrusion of a thermoplastic nonderivatized cellulose solution about a mandrel and through a long air gap in excess of 304 mm is facilitated by use of a mandrel which is extensible from the extrusion die. On extrusion start-up, the mandrel extends a short length from the die. For steady-state operation, the mandrel is extended its full length from the die. Also disclosed is a mandrel structure to facilitate the introduction of a nonsolvent liquid into the interior of the extruded tube at a high location on start-up of extrusion and at a lower location during steady-state operation. The mandrel also includes a sizing portion having circumferential grooves which gather gas bubbles that may evolve at the interface between the extruded tube and the sizing portion. Vertical channels in the sizing portion connect these grooves and provide the passage of gas bubbles into a volume below the mandrel.

Abstract: In a method for forming a cellulose tube suitable for use as a food casing or as cellophane film, in which a solution of nonderivatized cellulose, tertiary amine N-oxide and water is extruded through an air gap of at least five inches, and into a water bath, such that a wet cellulose tube is formed. The wet tube is inflated from about 55% to 140% or more and dried thereby substantially retaining its work-to-rupture characteristics, especially when compared to viscose-derived tubes.

Abstract: A nozzle assembly for forming hollow fibers, particularly a "Z-fiber" having longitudinally oriented trabeculae with the fiber wall, is provided. The nozzle assembly contains a replaceable nozzle cap, a replaceable seal-guide, and a retractable central bore used to supply core material for the hollow fibers. The Z-fibers are particularly useful in enabling cells, solutes, or the like, to enter the fiber wall and move longitudinally into the center of the fiber wall.

Abstract: In a method for forming a cellulose tube suitable for use as a food casing, in which a solution of nonderivatized cellulose, tertiary amine N-oxide and water is extruded through a die gap and the extruded tube downwardly flowed through an air length while being internally cooled, and passed into a water bath, the tube transverse direction tensile strength is substantially increased by drawing the extruded tube through an air length of at least about six inches.

Abstract: Polymeric, thin oriented films can be made by use of a combination of a hot blown process and a blown bubble process, i.e. a double bubble process. The resulting film has use in replacing PVC for in store stretch wrap applications. Very low density polyethylene, VLDPE, is an especially preferred material for this process. It may be used as a monolayer, or as one layer of a multilayer structure. In practicing the invention, the polymer is extruded and hot blown, and heated to a temperature above its orientation temperature. This heating can be accomplished by the use of a heated liquid reservoir or sock disposed at the lower end of the primary bubble, inside the bubble. The hot blown heated film is then passed through a first set of pinch rolls, re-inflated into a blown bubble, and collapsed at a second set of pinch rolls. Thin, tough and elastic packaging materials are obtained by this process.

Abstract: A process of expanding plastics film is disclosed, together with an apparatus for performing that process, in which expansion of the plastics film is performed under the control of a liquid providing a stable hydraulic mass, by the downward extrusion and drawing of the plastics film, and the final expansion thereof, exclusively under the influence of the static and dynamic pressure of a hydraulic mass, at a position spaced downwardly of the extrusion head, the hydraulic mass being one that remains in a liquid phase at all temperatures encountered during the step of lateral stretching of the plastics film, to the exclusion of vaporization of the hydraulic mass.

Abstract: A process for the production of a porous organic material, in particular an organic semi-permeable membrane, provided with a plurality of separate passageways, comprising dissolving a polymer in a solvent, using a drawplate comprising needles having a shape conjugate with that of the passageways and external dimensions comprising between 0.7 and 1.2 times those of said passageways and an extrusion orifice of a conjugate fome to that of the extrudate and of internal dimensions comprising between 0.8 and 1.2 times those of said extrudate, injecting around the needles a solution having a viscosity greater than 500 millipascal-second, introducing into the interior of the conduits of the drawplate a centering fluid which is a non-solvent with respect to the polymer and able to precipitate the polymeric solution, causing the extrudate to travel from the output of the drawplate a distance da in a gaseous atmosphere which is non-precipitating with respect to the polymeric solution such that 500.times.e<da<0.

Abstract: A method for the production of a hollow fiber membrane by the steps of discharging a spinning dope through an annular spinning nozzle and, at the same time, introducing a non-coagulating liquid for the spinning dope into the central cavity in a hollow fiber of the spinning dope being discharged, and then introducing the discharged fiber of the spinning dope into a coagulating liquid thereby solidifying the discharged fiber into a hollow fiber membrane, which method is characterized by incorporating a surface modifying agent in said non-coagulating liquid thereby modifying the inner surface behavior of the produced hollow fiber membrane.

Abstract: A process for the production of a porous organic material, in particular a semi-permeable membrane, comprising a plurality of separate passageways, including dissolving a polymer in a solvent, using a drawplate having needles of a shape conjugate with those of the passageways and of external dimensions between 0.7 and 1.2 times those of the passageways and an extrusion orifice of a shape conjugate those of the extrudate and of internal dimensions comprising between 0.8 and 1.2 times those of the extrudate, injecting around the needles a solution having a viscosity greater than 500 mPa.s and introducing a centering fluid into the interior of these needles, recovering the extrudate at the output of the drawplate in a precipitating medium in such a manner that the extrudate travels in the medium a distance such that 800.times.

Abstract: A process is disclosed for the production of biaxially oriented liquid crystal films. The process includes:(i) forming an anisotropic dope from a polymerization solution of rigid rod heterocyclic liquid crystalline polymers such as poly{[benzo(1,2-d:4,5-d')bisthiazole-2,6-diyl] 1,4-phenylene}, its cis isomer or mixtures thereof, and poly{[benzo(1,2-d:4,5-d')bisoxazole-2,6-diyl] 1,4-phenylene}, its cis isomer or mixtures thereof, and a solvent such as polyphosphoric acid;(ii) extruding the dope to form a film;(iii) imparting biaxial orientation to the film to increase the transverse strength thereof;(iv) solidifying the biaxially oriented film; and(v) washing the solidified film to remove the solvent. Also disclosed is a liquid crystal film produced by the above process.

Abstract: A process for providing film tubes with anti-blocking means in that the film tube is cooled internally by an aqueous suspension containing a suspended release agent directly after extrusion, the excess suspensions are sucked from the interior and the tube, which is additionally cooled on the exterior in a water bath, is freed of remaining liquid by squeezing rollers.

Abstract: Equally biaxially oriented film is produced by extruding liquified polymer in tubular form, orienting the tubular film in the radial direction only and then either (1) equally orienting the radially oriented film in the longitudinal direction and drying the resultant equally biaxially oriented film while preventing any shrinkage thereof or (2) orienting the radially oriented film in the longitudinal direction to a degree less than said radial orientation but equal to the radial orientation remaining after the biaxially oriented film undergoes radial shrinkage upon drying thereof in the absence of radial shrinkage control and drying the resultant biaxially oriented film in the absence of radial shrinkage control.

Abstract: The disclosure embraces a method of and apparatus for processing heat-softenable materials, such as glass, to form fibers or filaments from the streams of material and more particularly effecting successive distortions, oscillations or vibrations of the streams of glass by directing streams or jets of liquid for cooling or quenching the streams of glass at the region of formation of the fibers or filaments for establishing successive kinks, bends or crimps in the attenuated fibers or filaments, and delivering or conveying by the quenching streams of liquid or other streams of liquid powdered or particulate materials or metals for combining with, coating or reacting with the glass of the streams at the region of formation of the fibers or filaments for producing combined metal and glass fibers or filaments or coating the glass fibers or filaments with metals or other materials and utilizing electric current potential applied to the streams of liquid entraining metal or other particulate materials for establish

Abstract: Disclosed is a process for the continuous manufacture of fiber-reinforced tubing based on cellulose hydrate, comprising the steps of impregnating and coating fibrous tubing with an aqueous akaline viscose solution; moving the viscose-treated tubing at a steady speed vertically in a straight line along its longitudinal axis; applying a viscose-regenerating fluid along at least one circular circumferential line to at least the outside of the viscose-treated fibrous tubing; immediately after the application step, passing the tubing with the film of regenerating fluid on its surface through at least one first air section, whereby there is produced a fiber-reinforced tubing based on cellulose hydrate; treating the cellulose hydrate tubing with an aqueous fluid containing a dissolved chemical plasticizer; and drying the plasticized tubing. Also disclosed is an apparatus for carrying out this process.

Abstract: A molten thermoplastic resin is extruded in the form of a double-layer cylindrical hollow film with the two film layers being interconnected with each other by a number of spaced legs and is then immediately passed through an annular gap defined by annular side walls of inner and outer vessels in such a manner that the two film layers are in contact with the respective side walls defining the gap. Coolant is supplied to the inner and outer vessels and overflows above the side walls to bring the coolant into contact with the resin. The level of the coolant overflowing above both side walls is adjusted to be equal and also to have a liquid pressure on the extruded resin balanced with a gas pressure supplied in between the two film layers and the legs of the extruded resin.

Abstract: Apparatus as set forth in U.S. Pat. No. 3,796,781 for the production of quenched tubes of plastics materials, wherein the peripheral portions of the caibrating disc assembly that contact the wall of the tube during operation of the apparatus comprise a liquid absorbent material.

Abstract: The disclosure embraces a method of and apparatus for processing heat-softenable materials, such as glass, to form fibers or filaments from the streams of material and more particularly effecting successive distortions, oscillations or vibrations of the streams of glass by directing streams or jets of liquid for cooling or quenching the streams of glass at the region of formation of the fibers or filaments for establishing successive kinks, bends or crimps in the attenuated fibers or filaments, and delivering or conveying by the quenching streams of liquid or other streams of liquid powdered or particulate materials or metals for combining with, coating or reacting with the glass of the streams at the region of formation of the fibers or filaments for producing combined metal and glass fibers or filaments or coating the glass fibers or filaments with metals or other materials and utilizing electric current potential applied to the streams of liquid entraining metal or other particulate materials for establish

Abstract: This invention relates to a method and apparatus for integrating a newly formed continuous filament into a continuous strand. Mechanically complicated prior integration devices are usually expensive to purchase and operate and do not always ensure that the initially formed section of the new filament is separated from the new filament, that the fiber diameter of the new filament is predrawn sufficiently for ready integration, or ensure the reliability of the guiding elements facilitating integration. The present invention includes the operations of drawing a plurality of continuous filaments 3 from a bushing 1 into a fiber fan 4 by gathering the filaments 3 into a continuous strand 6 at a deflection point or roller 5. Should one of the filaments 3 break, a new continuous filament 8 is formed which is deflected by a guide plate 9 toward the point 5.

Abstract: Substantial and commercially important increases in polypropylene film production rates without adversely affecting film quality are obtained in a tubular water film process. The improvements comprise modifications in the die lip, in the mandrel air (fluid) slot affecting the cooling gas velocity, and in the upper bubble pressure control. The improvements are especially useful to obtain mill rolls 60 to 80 inches wide.