Abstract: Process for the production of cellulose shaped bodies through the precipitation of a cellulose solution containing cellulose dissolved in an amine oxide/water system in a precipitation bath, wherein the solution contains additional cellulose fibers.

Abstract: The present invention relates to novel dyed cellulosic molded bodies, in particular to fibers or films, containing a heavy-metal-containing colorant, which, according to the thermal stability test described above, reduces the rise temperature of a cellulose solution in a tertiary amine oxide by 10° C. at most, in particular by 5° C. at most. The molded bodies according to the invention may be produced in accordance with the amine-oxide process (FIG. 1).

Abstract: The invention relates to a device for the production of cellulosic tubular films by extruding a solution of cellulose in an aqueous tertiary amine oxide into a precipitant present below the device, which device comprises an extrusion die having a substantially annular extrusion gap, wherein a supply duct for precipitant and a discharge duct for used precipitant are provided in the interior of the ring formed by the extrusion gap, characterized in that the supply duct (3) for the precipitant terminates below the discharge duct (4) for the used precipitant.

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: A process of producing at least one filament of refractory material comprising: (a) preparing a spin mix of a solution of cellulose and particles of refractory material; (b) wet spinning the spin mix to form at least one filament of regenerated cellulose having at least a portion of the particles dispersed therein; and (c) heating the filament of regenerated cellulose to remove substantially all of the regenerated cellulose and to sinter the portion of the particles dispersed therein to form a filament of the refractory material.

Abstract: A method for preparing a hollow fiber-type separation membrane from high density polyethylene is provided, which includes the steps of: melt-spinning a mixture of a high density polyethylene and a diluting agent to produce a phase-separated undrawn hollow fiber; detecting a tensile strength of the undrawn fiber during an alternative and repetitive winding and unwinding procedure between two bobbins, said undrawn fiber being drawn during the alternative and repetitive winding and unwinding procedure; reducing a rotation speed of one of the two bobbins when the detected tensile strength is larger than a predetermined value; and increasing a rotation speed of one of the two bobbins when the detected tensile strength is smaller than the predetermined value to yield the hollow fiber-type separation membrane.

Abstract: The present invention is directed to methods of making lyocell fibers. In particular, the process includes reducing the average degree of polymerization of a pulp to about 200 to 1100 without substantially reducing the hemicellulose content of the pulp, and reducing the copper number to less than 2.0.

Abstract: The invention relates to a process for the production of cellulosic flat films whereby a solution of cellulose is extruded in an aqueous tertiary amine oxide by means of an extrusion die which has an extrusion gap whereby the solution is moulded in the shape of a film and the extruded solution is led via an air gap to a precipitation bath. The process in accordance with the invention is characterised in that an extrusion die is used which has an extrusion gap b of 220 &mgr;m≦b≦280 &mgr;m. Moreover, the invention relates to flat films, obtainable by the amine oxide process with a thickness d of less than 20 &mgr;m, a width B of more than 30 cm, and a factor f of 65 or less, whereby f is defined as f=d*(MD/TD), d is used in &mgr;m and whereby MD stands for the tenacity of the film in the longitudinal direction (N/mm2) and TD for the tenacity of the film in the transverse direction (N/mm2).

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: The invention relates to a process for the production of cellulosic fibres from solutions of cellulose in an aqueous tertiary amine oxide whereby the extruded fibres are led through a precipitating bath and cut and the cut fibres are passed through a series of water baths in the form of a fleece and then dried, whereby the wash baths are connected to each other and fresh washing liquor is applied to the last wash bath and led in countercurrent with the transportation direction of the fibre fleece to the first wash bath. The process in accordance with the invention is characterised in that the pH value of each of these wash baths is maintained higher than 8.5.

Abstract: Aromatic polyamide fibers which have a crystalline structure having (1) crystal size (A) in a (110) plane of 7.5 nm, (2) crystal size (B) in a (200) plane of 8.2 nm and (3) a product A×B of 61.50 to 630.00, and exhibit a thermal linear expansion coefficient of −1.0×10−6/° C. to −7.5×10−6/° C. and thus a high dimensional stability even upon moisture-absorbing and desorbing, are useful for forming a resin-reinforcing fiber sheet, a pre-preg containing the fiber sheet, and a laminate for, for example, an electric insulating material or electric circuit board, having an excellent cutting, shaving, perforating or laser processability and capable of forming a smooth cut, shaved or perforated face.

Abstract: Lyocell fibres contain elongated domains of polyester, polyamide or an olefin copolymer, the domains having an aspect ratio at least 1.5 and being aligned substantially parallel to the axis of the fibre. A process for the preparation of lyocell fibre or film by extruding a solution of cellulose in amine oxide through a spinneret or film die at elevated temperature via an air gap into an aqueous precipitation bath is characterised in that 0.1 to 60 wt % based on cellulose of a thermoplastic low-melting polymer is incorporated into the cellulose solution. A process for the preparation of a bicomponent fibre by extruding two polymers through a spinneret in side-by-side relationship at elevated temperature is characterised in that one of the polymers is a solution of cellulose in amine oxide and the other polymer is a molten thermoplastic polymer having a melting point above 25° C. but below the extrusion temperature.

Abstract: In the method of continuously producing pellets by continuously extruding a saponified ethylene-vinyl acetate (EVOH) solution in a strand form into a coagulation liquid and then cutting the resulting strand, the ratio between the weight X of the coagulation liquid and the weight Y of the strand of the saponified ethylene-vinyl acetate copolymer, namely the ratio X/Y, is set at 50 to 10,000. The coagulation liquid preferably contains 1 to 10,000 ppm of a carboxylic acid, 1 to 50,000 ppm of a carboxylic acid ester, or 1 to 15,000 ppm of a carboxylic acid salt. It is preferred as well that the water content of the continuously produced EVOH pellets be adjusted to 20 to 80% by weight and then brought into contact with an aqueous solution, having at least one boron compound, an acetic acid salt and a phosphoric acid compound.

Abstract: The invention is lyocell fiber characterized by a pebbled surface as seen at high magnification and having a variable cross section and diameter along and between fibers. The fiber is produced by centrifugal spinning, melt blowing or its espunbonding variation. The fibers can be made in the microdenier range with average weights as low as one denier or less. The fibers have inherently low gloss and can be formed into tight yarns for making fabrics of very soft hand. Alternatively, the fibers can be formed into self bonded nonwoven fabrics.

Abstract: Stable, concentrated solutions of high molecular weight polyaniline. In order to process high quality fibers and other articles possessing good mechanical properties, it is known that solution concentrations of the chosen polymer should be in the range from 15-30% (w/w). Moreover, it is desirable to use the highest molecular weight consistent with the solubility properties of the polymer. However, such solutions are inherently unstable, forming gels before processing can be achieved. The present invention describes the addition gel inhibitors (GIs) to the polymer solution, thereby permitting high concentrations (>15% (w/w)) of high molecular weight ((M.sub.w)>120,000, and (M.sub.n)>30,000) emeraldine base (EB) polyaniline to be dissolved. Secondary amines have been used for this purpose in concentrations which are small compared to those which might otherwise be used in a cosolvent role therefor.

Abstract: A process for the production of cellulose fibers, comprising the following steps:(A) dissolving a cellulose-containing material in an aqueous, tertiary amine-oxide to obtain a spinnable cellulose solution;(B) spinning said cellulose solution and passing it through an aqueous precipitation bath, whereby water-containing, swollen filaments are obtained;(C) squeezing said water-containing, swollen filaments at various points, so that at least two squeezing points per millimeter of filament length on average are achieved and(D) drying said squeezed filaments to cellulose fibers, wherein squeezing is carried out using a pressure big enough so that said squeezing points produced on the filament are preserved also on the dried fibre and may be seen as color variations when observed under linearly polarized light.

Abstract: A method and apparatus is disclosed for forming a cellulose film suitable for direct food contact by precipitation from a solution of cellulose water and a tertiary amine oxide cellulose solvent. After precipitation of a cellulose gel from the solution, the gel is washed at ever increasing temperatures and then dried to provide a cellulose film having a solvent level to not more than 40 ppm. Portions of the wash water is collected and treated to recover the solvent for reuse.

Abstract: The fibrillation tendency of solvent-spun fiber can be increased by subjecting the fiber to a treatment which reduces its degree of polymerisation by about 200 units or more. Suitable methods of treatment include severe bleaching, for example application of an aqueous liquor containing 0.1 to 10 percent by weight sodium hypochlorite (as available chlorine) to the fiber followed by steaming. Fiber may be treated in never-dried or previously-dried form. Fiber treated by the process of the invention is useful for example in the manufacture of paper and hydroentangled fabrics. Fiber of increased tendency to fibrillation can be beaten to a Canadian Standard Freeness 400 in the Disintegration Test by 30,000-150,000 disintegrator revolutions and to a Canadian Standard Freeness 200 in the same Test by 50,000-200,000 disintegrator revolutions.

Abstract: A method for producing cellulosic dialysis membranes in the form of flat, tubular, or hollow fiber membranes by spinning a spinning solution of cellulose and/or modified cellulose, a tertiary amine oxide, and additional liquids and additives such as stabilizers, pore formers and the like is provided. The method operates at high takeoff speed and produces membranes for the low, middle, and high flux ranges. The membranes show practically no aging and have a stable structure. The oxidative breakdown of cellulose in the manufacture of the membranes is extremely low and hemocompatability is very good.

Abstract: Cellulosic fibers made from a solution of cellulose in a tertiary amine oxide and optionally water and which have a low tendency to fibrillate are produced by coagulating the fibers in at least two stages. The residence time of the fibers in the first coagulation stage is adjusted so that on leaving the first coagulation stage only the adhesiveness of the surface of the solution formed into fibers has been counteracted. In subsequent coagulation stages, the fibers are kept in a slack state. On leaving the final coagulation stage, the fibers have been thoroughly coagulated. The cellulosic fibers have a new structure and apart from a very low tendency to fibrillate, they possess a high dyeing level.

Abstract: A process for preparing filaments of polyketones which can be formed into various fibers is presented. The process involves preparing a solution of polyketone in a solvent, passing the solution through a die to produce a strand, coagulating the strand to produce a filament, removing solvent from the presence of the filament, and subsequently drawing the filament. The solvents are zinc and lithium based solutions.

Abstract: The invention provides improvements in processes for film and fiber production involving precipitating cellulose from tertiary amine oxide solutions wherein a water soluble polymer is incorporated into the solution in an amount sufficient to slow precipitation of the cellulose during separation of the cellulose from the tertiary amine oxide.

Abstract: A method of producing lyocell fibers by spinning a solution of cellulose in an organic solvent through an air gap and into a spin bath in which there is provided a cross-draught of air in the air gap.

Abstract: A wet-spinning fiber process which controls the micro-structure of the wepun fiber by varying the non-solvent/solvent miscibility and precipitation strength.

Abstract: A method of producing lyocell fibres by spinning a solution of cellulose in an organic solvent through an air gap and into a spin bath in which there is provided a cross-draught of air in the air gap.

Abstract: There is provided a cord of twisted polybenzazole fibers, which has a tenacity of 35 g/d or higher and an elastic modulus of 800 g/d or higher. The cord has not only remarkably improved fatigue resistance but also excellent mechanical characteristics at a high level that has not been achieved so far. Therefore, it can attain the weight reduction of composite materials, particularly in the field of reinforced rubber materials, and can also make a great contribution to the energy saving.

Abstract: A fiber containing an organic acid salt of an intrinsically conductive polymer distributed throughout a matrix polymer along with a method for providing such fibers by spinning a solution which includes an organic acid salt of an intrinsically conductive polymer, a matrix polymer and a spinning solvent into a coagulation bath including a nonsolvent for both the organic acid salt of an intrinsically conductive polymer and the matrix polymer. The intrinsically conductive polymer-containing fibers typically have electrical conductivities below about 10.sup.-5 S/cm.

Abstract: Methods are disclosed for making semipermeable membranes from cellulose acetate and for making medical devices therefrom. In the process, a molten liquid comprising cellulose acetate (CA) is extruded to produce a membrane. The solvent and non-solvent are removed from the membrane to produce a semipermeable membrane having a water permeability. The semipermeable membrane is impregnated with a liquid consisting essentially of water to render the semipermeable membrane capable of being stored until time of use without undergoing a substantial loss in water permeability. The semipermeable membrane can be incorporated in a casing in order to produce a medical product, wherein the membrane is impregnated in the product.

Abstract: The invention relates to a process for preparing a microporous membrane from an unsulfonated poly(phenylene sulfide) polymer by forming a mixture of an unsulfonated poly(phenylene sulfide) polymer, an amorphous polymer, and optionally a plasticizer, heating the resulting mixture, extruding or optionally casting the mixture into a membrane, controlled cooling (quenching) or coagulating the membrane, and leaching the membrane, while optionally drawing the membrane before, during, and/or after leaching.

Abstract: A polyimide fiber having textile physical property characteristics and the process of melt extruding same from a polyimide powder. Polyimide powder formed as the reaction product of the monomers 3,4'-ODA and ODPA, and endcapped with phthalic anhydride to control the molecular weight thereof, is melt extruded in the temperature range of 340.degree. C. to 360.degree. C. and at heights of 100.5 inches, 209 inches and 364.5 inches. The fibers obtained have a diameter in the range of 0.0068 inch to 0.0147 inch; a mean tensile strength in the range of 15.6 to 23.1 ksi; a mean modulus of 406 to 465 ksi; and a mean elongation in the range of 14 to 103%.

Abstract: The disclosure describes a process for the manufacture of cellulosic moulded bodies in which cellulose is dissolved in a mixture of a tertiary amine oxide and a non-solvent for cellulose, e.g. water. The solution is extruded via a moulding tool and the filaments received are led via an air gap to a precipitation bath whilst being drawn. The process is characterised in that the precipitation bath substantially comprises a non-aqueous solvent for the tertiary amine oxide, whereby the molecular weight of the non-aqueous solvent is larger than that of the tertiary amine oxide. In this manner, solvent-spun fibers with a lower fibrillation tendency can be obtained. Polyethylene glycols are preferably used.

Abstract: It has been found that fibres can be spun in a simple manner from polyketone polymer solutions by making a thermoreversible gel from a solution of polyketone and a solvent for the polymer having a boiling temperature above 443 K, a melting temperature below 373 K, and a polymer dissolving temperature above 443 K. The thermoreversible gel forms as the solution is cooled. Because of the specific properties of the solvent in combination with the concentration of the polymer and its intrinsic viscosity, a permanently orientable thermoreversible gel is formed by cooling. The polymer crystallises on being cooled, optionally while still in the presence of the solvent. Preferably, so much polymer is dissolved as will give a product of the polymer concentration and ?.eta.!.sup.0.5 (wherein ?.eta.! represents the intrinsic viscosity of the polymer) of higher than 0.35 (dl/g).sup.0.5.

Abstract: The invention is concerned with a process for transporting a solution of cellulose in an aqueous tertiary amine-oxide through a component wherein said cellulose solution has different flow rates in said component, characterized in that an outlet wherethrough part of said cellulose solution is discharged from said component is provided at a point within said component whereat said flow rate is relatively low. (FIG.

Abstract: Solvent-spun cellulose fibers having a reduced tendency to fibrillate are produced by treating the fibers with one or more compounds from the group of the(A) N-methylol ethers of carboxamides, urethanes, ureas and aminotriazines,(B) N-alkyl-mono- or polysubstituted cyclic hydroxy- or alkoxy-ethyleneureas,(C) hydrophilic modified polyisocyanates, and(D) mixtures of polyurethanes with isocyanates.

Abstract: A method for preparing optical quality, thin films of polymers and co-polymers, as well as blends of such polymers or co-polymers with flexible polymers and co-polymers which comprises(a) preparing a solution of the polymer or co-polymer or blend in a suitable solvent;(b) forming a film from the solution;(c) cooling the thus-formed film to a temperature below the freezing point of the solvent; and(d) dissolving the solvent out of said film at a temperature below the melting point of the solvent.This method can be employed to prepare films of high optical clarity for electro-optical device applications. Because of their thermal stability, mechanical strength and chemical resistance, films prepared according to this method can also be used as filters and separation membranes.

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: It is known to wash dispersion noodles in a `batchwise` fashion in which the noodles are retained in a kettle or kettle and water is sprayed onto the surface of the noodles. Agitation is achieved by bubbling air into the kettle from the bottom. Described herein is a method and apparatus for continuously washing dispersion noodles. The apparatus includes continuous pipe work in which the noodles are washed, the pipe work including at least one separating device (10) for separating the noodles from the water in which they have been washed. The device (10) comprises a housing (12) having an inlet (14) and an outlet (16). A separating element (22) is located in the housing (12) between the inlet (14) and the outlet (16) and is surrounded by a collection chamber (24), the element (22) comprising a tube of mesh material through which water passes into the collection chamber (24) and which is then drained off through drain (32).

Abstract: A process for the preparation of polybenzazole filaments which comprises (a) extruding a solution of polybenzazole polymer in a mineral acid through a spinneret having at least 100 holes, which are arranged to form a annular pattern around the center of the spinneret, the center and at least two radial sections of the spinneret having no holes and an average width which is at least about 3 times the minimum pitch of the holes, thereby forming filaments of the polymer solution; (b) drawing the filaments of the polymer solution through a quench chamber while providing a substantially radial gas flow therein across the spinneret from at least two different directions; and (c) washing and drying the filaments of the polymer solution under conditions sufficient to form polybenzazole filaments.

Abstract: A crosslinked cellulose composite film including a regenerated cellulose matrix containing a uniform dispersion of hemp fibers and a poly(ethylene oxide) plasticizer. A method for forming the film includes mixing a slurry of the hemp, poly(ethylene oxide) and a cellulose solvent with a cellulose solution, extruding the mixture, regenerating the cellulose from the solution to form the matrix containing hemp fibers, contacting with a crosslinking agent and then drying.

Abstract: An adjustable reaction tub for making tubular cellulosic casings from viscose, the tub having upper rollers mounted to a frame and lower rollers on a roll support mounted to the same frame for adjustable positioning of the lower rollers at any of a range of depths within the tub.

Abstract: A process of manufacturing lyocell fiber with an increased tendency to fibrillation which includes dissolving cellulose in a tertiary amine N-oxide solvent to form a solution. The degree of polymerization of the cellulose is not more than about 450 and the concentration of cellulose in the solution is at least 16 percent by weight. The solution is extruded through a die to form a plurality of filaments which are washed to remove the solvent, thereby forming the lyocell fiber which is then dried.

Abstract: The invention relates to polyketone yarns of which the maximum tangential modulus at an elongation of more than 0.2% is at least 10 N/tex which display both high strength and, if so desired, a high elongation at break. The quality number, which is measured on a single filament out of a bundle of at least about 30 filaments spun simultaneously through one spinneret and given as .sigma., .epsilon., is higher than 85 mN/tex, preferably higher than 100 mN/tex. The quality number of a yarn spun through one spinneret of one or more holes is higher than 110 mN/tex, preferably higher than 120 mN/tex. The yarns are manufactured by extruding a solution of a linear polymer of alternating ethylene and carbon monoxide units in a resorcinol-containing solvent, after which the solvent is removed with the aid of methanol as coagulant.

Abstract: Perfluorinated cycloalkane solvents for dissolving high melting polymers containing tetrafluoroethylene, are disclosed. These solvents dissolve such polymers more rapidly, and/or are more stable, than previously known solvents. Also disclosed is a process for dissolution of the polymers and their resulting solutions. The solutions are useful for making polymer films, coatings and for encapsulating objects.

Abstract: A method of forming a flame retardant cellulose fiber is disclosed which comprises the steps of producing lyocell fiber and incorporating a flame retardant chemical into the fiber while the fiber is in the never-dried condition prior to first drying.

Abstract: A hydrophilic polymer alloy which has a permanent hydrophilic nature, a sufficient mechanical strength and a high safety and which is suitable for the formation of hydrophilic porous membranes manufacturable by an industrially advantageous process can be prepared by blending an amorphous hydrophilic copolymer (X) containing 10 mole % or more of an ethylene unit, 10 to 60 mole % of a vinyl alcohol unit and 1 mole % or more of a vinyl acetate unit with a polyolefin (Y). Furthermore, this polymer alloy is also suitable for the formation of hydrophilic (porous) fibers having a sufficient mechanical strength and antistatic function.

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: Methods are disclosed for making semipermeable membranes from cellulose acetate and for making medical devices therefrom. In the process, a molten liquid comprising cellulose acetate (CA), a solvent for CA, and a non-solvent for CA is extruded to produce a membrane. The solvent and non-solvent are removed from the membrane to produce a semipermeable membrane having a water permeability. The semipermeable membrane is impregnated with a liquid consisting essentially of water to render the semipermeable membrane capable of being stored until time of use without undergoing a substantial loss in water permeability. The semipermeable membrane can be incorporated in a casing in order to produce a medical product, wherein the membrane is impregnated in the product.

Abstract: Soluble wholly aromatic polyamide is obtained by low-temperature polycondensation in an amide solvent such as N-methyl-2-pyrrolidone. The reaction mixture is neutralized with an alkali and spun into fibers by wet spinning, coagulated in a salt-free aqueous solution of an organic solvent, preferably the polymerization solvent, and subsequently drawn in another aqueous solution of the same organic solvent, both solutions being substantially at ambient temperatures below 50.degree. C. but above freezing, More than 60% of the total fiber drawing is executed in this low-temperature draw stage.

Abstract: A spinning cell for producing lyocell fibre by spinning a solution of cellulose in an organic solvent through an air gap into a spin bath has nozzles to create a cross-draught through the air gap.