Abstract: A spinning apparatus includes a spinning cabinet extending in a vertical direction, a spinneret that includes a plurality of spinneret holes, is disposed on an upper end side of the spinning cabinet, and is configured to extrude a spinning dope from the plurality of spinneret holes into an interior space of the spinning cabinet, a first gas supply path connected to the spinning cabinet is configured to supply a first gas from above the spinneret to the interior space, allowing the first gas to come into contact with the spinning dope extruded from the plurality of spinneret holes, and a second gas supply path connected to the spinning cabinet is configured to supply a second gas having a higher temperature than that of the first gas from below the spinneret to the interior space, allowing the second gas to come into contact with the spinning dope extruded from the plurality of spinneret holes.

Abstract: The present disclosure discloses a method for preparing cellulose fiber. The method includes the following steps: 1) mixing cellulose pulp with NMMO aqueous solution of a mass concentration of 60%-85%, preferably 70% to 76%, to obtain a uniform mixture; 2) subjecting the obtained uniform mixture to dewatering for swelling, dissolution, and deaerating to obtain a cellulose spinning stock solution; 3) the cellulose spinning stock solution entering into a spinning machine after being filtered and heat exchange, and entering into a coagulation system after carrying out extruding by a spinneret-pack and cooling by air, and then coagulating in a NMMO coagulating bath of a mass concentration of 50% to 72% to obtain nascent fiber; and 4) subjecting the nascent fiber to rinsing to obtain a fiber filament bundle, and then, performing subsequent-section treatment to obtain cellulose fiber.

Abstract: A method of manufacturing a polyacrylonitrile fiber includes a spinning process in which a spinning dope including polyacrylonitrile is spun; a first drawing process; a drying process; and a second hot drawing process in this order.

Abstract: An apparatus and process for depositing slurry upon a moving forming web. The apparatus includes a pivotally mounted headbox for depositing slurry from the inner bottom surface of the headbox down an inclined spillway as a continuous curtain onto a moving web. The headbox is mounted transverse to the direction of travel of the moving web. The headbox also has vertical edge boards, including a headbox back edge board and two opposed headbox side edgeboards, on three respective sides of the headbox to prevent slurry from spilling over the sides and back of the headbox. The headbox is supplied with slurry from a slurry mixer by a feed line mounted on a reciprocating trolley which moves, transverse to the direction of travel of the moving web, back and forth along the length of the headbox.

Abstract: The invention relates to a process for preparing a composition comprising 10 to 45% of the total solids weight lignin, polyacrylonitrile or a polyacrylonitrile copolymer, and a solvent to form a lignin-based polyacrylonitrile-containing dope and the resulting products. The dope can be processed to produce fibers, including precursor, oxidized and carbonized fibers. The oxidized fibers are of value for their flame resistant properties and carbonized fibers are suitable for use in applications requiring high strength fibers, or to be used to form composite materials.

Abstract: The invention relates to a process for preparing a composition comprising 10 to 45% of the total solids weight lignin, polyacrylonitrile or a polyacrylonitrile copolymer, and a solvent to form a lignin-based polyacrylonitrile-containing dope and the resulting products. The dope can be processed to produce fibers, including precursor, oxidized and carbonized fibers. The oxidized fibers are of value for their flame resistant properties and carbonized fibers are suitable for use in applications requiring high strength fibers, or to be used to form composite materials.

Abstract: Process for the production of acrylic fibre, for fabrics with a low pilling formation, having a titer within the range of 1.0 to 5.6 dtex, which comprises the wet spinning in a solvent of a copolymer essentially consisting of acrylonitrile, in a quantity within the range of 97 to 99.99% by weight, and a comonomer with a strong acid group of the sulfonic type having the general formula: CH2?C(R)—CH2SO3—M wherein R represents a hydrogen atom or the CH3 radical whereas M represents a hydrogen atom or an alkaline metal in a quantity ranging from 0.01 to 3% by weight.

Abstract: Fusion cast indium zinc oxide articles and methods of manufacturing fusion cast indium zinc articles are disclosed. The fusion cast indium zinc articles can be used as sputtering targets for forming transparent conductive films.

Abstract: Porous acrylic fibers produced by a method comprising subjecting a spinning dope containing 0.3 to 20 parts by weight of poly(vinyl acetate) relative to 100 parts of an acrylic copolymer to a wet spinning to give fibers, crimping and cutting the fibers, subjecting the resultant fibers to a treatment by hot water at 90 to 100° C. for 30 to 120 minutes or by saturated steam at 90 to 130° C. for 10 to 90 minutes to thereby form porous fibers; and a pile fabric having pile portions which comprise the porous fibers in an amount of 3 wt % or more, and, in the pile fabric, respective single fibers are visible being separate and emphasized, and thus the pile fabric has an appearance being highly decorative and excellent in design characteristics.

Abstract: A solution spinning process for the production of a textile fiber with permanent repellent action includes the steps of preparing a spinnable polymer component and an ambivalent polymer compound which contains a repelling group and a residual group with an affinity for the spinnable polymer component, mixing the ambivalent polymer compound with the spinnable polymer component in a solvent, and spinning the mixture into a fiber, wherein the repelling groups orient themselves in the direction of the surface of the forming fiber and migrate to the surface, while the affine residual groups anchor the ambivalent polymer compound in the spinnable polymer compound as the solvent is driven off.

Abstract: There is disclosed an acrylonitrile fiber bundle for a carbon fiber precursor with a total denier of 30,000 or more consisting of an acrylonitrile polymer comprising 95 wt % or more of an acrylonitrile unit, wherein the surface of filaments composing of the fiber bundle has 2 to 15 corrugation with a height of 0.5 to 1.0 &mgr;m which are substantially continuous in a longitudinal direction and an iodine adsorption per a fiber weight of the fiber bundle is 0.5 to 1.5 wt %. The fiber bundle shows a large total size, a small drying load owing to its good denseness and a good convergence so that it is suitably used as precursors for carbon fibers.

Abstract: A process and apparatus for the production of polyacrylontrile (PAN) polymer fibers from a polyacrylonitrile polymer, wherein a polyacrylonitrile polymer that comprises 90 weight percent or more polyacrylonitrile, optionally mixed with from about 30 to about 50 weight percent, based on the weight of the polymer, of a fugitive plasticizer, is heated, provided to an extruder in liquid form, extruded to form polyacrylonitrile fibers, and the fibers, immediately after the extrusion, are cooled, preferably in an air-cooled manifold, to a temperature of from about 110 to about 135° C.

Abstract: The carbon fiber precursor fiber bundle of the present invention is an acrylonitrile-based fiber bundle wherein the ratio of the length and width of the fiber cross section of a monofilament (length/width) is 1.05 to 1.6, and the amount of Si measured by ICP (Inductively Coupled Plasma) atomic emission spectrometry is in the range of 500 to 4,000 ppm. This type of carbon fiber precursor fiber bundle has a high compactness, and the carbonizing processing ability is good. Furthermore, for the carbon fiber bundle which is to obtained hereafter, the resin impregnating ability and tow spreading ability are good, the strength increases, and it has bulkiness. Furthermore, the carbon fiber precursor fiber bundle of the present invention is an acrylonitrile-based fiber bundle wherein the liquid content ratio HW is 40 wt. % or more and less than 60 wt. %.

Abstract: An acrylic fiber tow having a total size of at least 22,000 dtex and a weight variation ratio in the longitudinal direction of not greater than 3.5%, which is useful as a precursor for carbon fiber production.

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: A process for producing a homogeneous phase melt of polyacrylonitrile suitable for extrusion molding and melt spinning, by the steps of preparing polymer/water crumb containing 30-60 wt % of polyacrylonitrile and dewatering the crumb in a molten state with stirring at temperatures above 140.degree. C. and at pressures above autogenous pressure until the concentration of the polymer in the crumb exceeds 70% by weight.

Abstract: This invention offers the porous fiber in which the porous form of the fiber is with an excellent durability to heat and accordingly can afford the fiber products with a shape-retaining ability.Porous acrylonitrile fiber comprising the polymers containing not less than 95% by weight of acrylonitrile in a bonded form whereby the pores in the fiber constituting the porous structure are connected each other and are communicated with the fiber surface and, in addition, having a specific decreasing rate in the average pore diameter due to an introduction of a crosslinking structure thereinto.It is possible to offer a porous acrylonitrile fiber which has a porous structure wherein the micropores in the fiber are connected each other and are communicated with the fiber surface and also exhibits an excellent retaining ability of the shape of the fiber.

Abstract: A multi-layered conjugated acrylic fiber comprises different acrylic polymers which are conjugated along the fiber axis in layers. On the average the fiber contains more than two layers of acrylic polymers. The shrinkage forming ratio in boiling water of the conjugated acrylic fiber is 7-15% and the shrinkage forming stress is 5-20 mg/denier. To make the acrylic fiber water absorbent, one or more of the acrylic polymers may contain 0.3 to 2.0 mmole/g of carboxylic acid groups. The fibers may be made by introducing the polymers into a static mixer in such a way as to retain a number of separate layers of the polymers, and thence to a spinneret through a filter having a maximum mesh space of 10 or more. After spinning out the dope, it is drawn, washed and dried. Except where water-absorbent fiber is wanted, this is followed by shrinkage forming treatment and redrawing; the water-absorbent fiber is treated with alkali solution either in the form of yarn, or a fabric made therfrom.

Abstract: A process for the production of pulp-like short fibers having a highly-oriented fibril structure without spinning is provided. This process comprises heating a mixture of water and an acrylonitrile homopolymer or copolymer to a temperature above the melting temperature of the mixture under enclosed conditions to form an amorphous melt; cooling the resulting amorphous melt to a temperature below the melting temperature to obtain a supercooled melt phase; extruding the resulting supercooled melt phase through a slit die at a temperature between the melting and the solidifying temperatures of the melt phase into an external atmosphere to give extrudates; and subjecting the resulting extrudates to drawing and heat treatment followed by beating mechanically.

Abstract: The stiffness and the tensile strength of a rope containing polymeric filaments manufactured according to the gel spinning process are substantially increased by stretching it. The stretching is preferably carried out at elevated temperature but below the melting point of the filaments.

Abstract: The process for production of polyacrylonitrile hollow threads with a stable, asymmetric pore structure by a dry-wet-spinning process with glycerine-based core liquids, definite draw and after treatment conditions and a treatment with alcohols and drying.

Abstract: A process for the discontinuous or (preferably) continuous production of dry spun hydrophilic acrylic fibers and threads with a core/sheath structure which have improved color fastness properties, more uniform cross-sections and better processing characteristics. By employing a new after-treatment combination of more intensive counterflow washing, stretching in steam, fixing in steam and careful drying of the fibers as staple fibers, improved hydrophilic fibers with a water retention capacity above 30% can be obtained from spinning solutions which have a much lower non-solvent content than is necessary in the present-state of the art for obtaining a high water retention capacity of the order indicated above.

Abstract: A process for dry spinning of synthetic polymers, in particular PAN threads containing more than 85 wt. % acrylonitrile in the PAN (co)polymer, with high spinning chimney capacities of at least 20 kg PAN solid per spinning chimney and hour, using superheated steam as the spinning gas and with in-chimney finishing with water or aqueous finishes.

Abstract: A process for the production of crimped filaments and fibers of acrylonitrile polymers of copolymers containing at least 40% by weight acrylonitrile units, by dry spinning from highly polar solvents, where the filaments are brought to extremely low solvent contents in the actual spinning tube by a minimum of superheated steam prepared in the absence of water at very high spinning tube temperatures and spinning gas temperatures, but are cooled to low filament temperatures in the spinning tube by application of water or aqueous finishes in a quantity equivalent to more than 10% by weight moisture. In this way, spun PAN filaments of good natural color are safely obtained, in which there is no washing stage and no drying stage. Acrylic fibers and filaments combining a vacuolestable structure with a very high degree of whiteness and gloss are thus obtained with densities of at least 1.180 g/cm.sup.3, giving shrinkage-free to high-shrinkage fibers, depending on the aftertreatment applied.

Abstract: A process for the dry spinning of synthetic polymers, in particular polyacylonitrile fibres, from solutions in high polar solvents, such as dimethylformamide, which are heated to 100.degree.-150.degree. C. shortly upstream of the spinneret and spun there by spinnerets having a certain shape, and in the spinning cell the specific energy supply is at least 0.090 kWh per m.sup.2 of heated cell area, the cell is charged with at least 70 m.sup.3 (S.T.P.) of hot air per hour, and the filaments are treated in the lower part of the cell with water or aqueous preparations, so that the temperature of the filaments which leave the cell is decreased below 110.degree. C. Under these conditions, the unexpectedly high spinning cell outputs of at least 20 kg of PAN solid per spinning cell per hour can be achieved without yellowing or self-ignition of the filaments occurring.

Abstract: A fiber or filament of a swellable polymer of high tensile strength is made by spinning a polymeric raw material which is produced by agitating a suspension of solid particles of an acrylonitrile polymer in dilute sulfuric acid having an acid concentration between 40 to 50 percent by weight until the polymer is hydrolyzed to an extent that it contains from 10 to 30 percent by weight of carboxyl groups such that sticking of individual particles of the polymer to one another is avoided.

Abstract: Acrylic fibers with high physical properties particularly suitable as material for cement reinforcement are provided by spinning a spinning solution of an acrylonitrile polymer at a particular linear velocity ratio of extrusion, thereby forming gel fibers; regulating the internal water content of the gel fibers, subjecting the fibers to dry-heat treatment under tension or dry-heat stretching under a particular temperature condition; and cooling the fibers under tension.

Abstract: An acrylic multifilamentary material possessing an internal structure which is particularly suited for thermal conversion to high strength carbon fibers is formed via a specifically defined combination of processing conditions. The acrylic polymer while in substantially homogeneous admixture with appropriate concentrations (as defined) of acetonitrile and water is melt extruded and is drawn at a relatively low draw ratio which is substantially less than the maximum draw ratio achievable. This fibrous material which is capable of readily undergoing drawing is passed through a heat treatment zone wherein the evolution of residual acetonitrile and water takes place. The resulting fibrous material following such heat treatment is subjected to additional drawing to accomplish further orientation and internal structure modification and to produce a fibrous material of the appropriate denier for carbon fiber production.

Abstract: An acrylic multifilamentary material possessing an internal structure which is well suited for thermal conversion to high strength carbon fibers is formed via a specifically defined combination of processing conditions. The acrylic polymer while in substantially homogeneous admixture with appropriate concentrations (as defined) of C.sub.1 to C.sub.2 nitroalkane and water is melt extruded and is drawn at a relatively low draw ratio which is substantially less than the maximum draw ratio achievable. During the melt extrusion a C.sub.1 to C.sub.4 monohydroxy alkanol preferably also is present in the substantially homogenous admixture. The fibrous material which is capable of readily undergoing drawing next is passed through a heat treatment zone wherein the evolution of residual nitroalkane, monohydroxy alkanol and water takes place.

Abstract: In a method of manufacturing carbon fiber with less uniformity of physical strength in the longitudinal direction, an oil additive in a volatile medium is applied to an organic fiber after it is removed from a container and while the volatile medium has not completely evaporated from the fiber, and before the fiber is fed to a flameproofing furnace.

Abstract: A carbon fiber of high strength is disclosed, each filament of which is substantially circular in its cross-section but which has circumferential ruggedness which extends in parallel to an axis of the filament to form pleats. The ruggedness has a depth of more than 0.1 .mu.m.The carbon fiber is prepared by extruding a spinning solution of an aqueous polyacrylonitrile/pure zinc chloride solution of a specified polymer content into a coagulating bath at a specified draft ratio, followed by washing, drying and stretching at a total stretching ratio of 10-20 folds to form a precursor which is then subjected to conventional stabilizing and carbonizing steps.

Abstract: An acrylic multifilamentary material possessing an internal structure which is particularly suited for thermal conversion to high strength carbon fibers is formed via a specifically defined combination of processing conditions. The acrylic polymer while in substantially homogeneous admixture with appropriate concentrations (as defined) of acetonitrile, C.sub.1 to C.sub.4 monohydroxy alkanol, and water is melt extruded and is drawn at a relatively low draw ratio which is substantially less than the maximum draw ratio achievable. This fibrous material which is capable of readily undergoing drawing is passed through a heat treatment zone wherein the evolution of residual acetonitrile, the monohydroxy alkanol and water takes place. The resulting fibrous material following such heat treatment is subjected to additional drawing to accomplish further orientation and internal structure modification and to produce a fibrous material of the appropriate denier for carbon fiber production.

Abstract: A process of producing carbon fibers, which comprises oxidizing polyacrylonitrile filaments having a tensile strength at 240.degree. C. of 0.3 g/d or higher and a tensile modulus at 240.degree. C. of 2.0 g/d or higher in an oxidizing atmosphere under a high tension of 0.2 g/d or higher, and carbonizing the oxidized filaments under a high tension.

Abstract: Polyacrylonitrile articles, such as filaments, tapes and films, having high tensile strength and modulus, and prepared by adding to a solution of polyacrilonitrile with a molecular weight above 3.times.10.sup.5, preferably above 5.times.10.sup.5, a minor amount of a bivalent metal compound, converting the solution into a solvent containing article, cooling this article to form a gel article, removing from this gel the solvent and metal compound, and stretching the resulting article at increased temperature. With this process filaments with a tensile strength above 1.2 GPa and a modulus above 16 GPa can be obtained.

Abstract: Ceramic alloys or solid solutions are formed by dispersing a powdery metal alloy or intimate mixture of two alloying metals in a precarbonaceous polymer such as polyacrylonitrile, forming the mixture into a molded article such as fibers, and heating the molded articles at a temperature and in a pyrolyzation atmosphere sufficient to carbonize the polymer and cause reaction of the metals with carbon and/or the pyrolyzation gas.

Abstract: A process for producing an acrylic fiber comprising the steps of:(a) dissolving a polymer having a weight-average molecular weight of at least 5.times.10.sup.5 and containing at least 80 wt. % acrylonitrile in a solvent comprising dimethylformamide or dimethylacetamide at a polymer concentration of 5-15 wt. % to provide a spinning solution having a viscosity of 500-1,500 poises at 45.degree. C.;(b) extruding the solution into a gaseous medium to form filaments;(c) introducing the filaments into a coagulation bath comprising water and at least one of dimethylformamide and dimethylacetamide at 0.degree. C. or below; and(d) stretching the coagulated filaments to a draw ratio of at least 3 to provide an acrylic fiber having at least 90% X-ray orientation and an X-ray crystallinity parameter of up to 1 degree. The resulting acrylic fiber has high strength and high modulus.

Abstract: A process for producing preoxidized fibers, which comprises preoxidizing acrylic fibers having a fluorine-containing surface active agent and at least one phosphoric surface active agent selected from the group consisting of compounds represented by the following formulae (I), (II) and (III), and preoxidizing the acrylic fibers thus-obtained: ##STR1## wherein R.sub.1 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms, R.sub.2, R.sub.3 and R.sub.4, which may be the same or different, and each represents a hydrogen atom, a lower alkyl group, a hydroxyethyl group or a hydroxyisopropyl group, ##STR2## wherein R.sub.5, R.sub.6 and R.sub.7, which may be the same or different, each represents a hydrogen atom or a hydroxyethyl group.

Abstract: Polyacrylonitrile (PAN) fibers are prepared by forming a 2-15 weight % solution of PAN of M.sub.w at least 500,000, extruding, cooling to below the gel temperature, extracting and drying. At least one of the gel fiber, the fiber containing extraction solvent and the dried gel is stretched. The product PAN fibers have a M.sub.w at least 500,000 (e.g. 1,000,000-4,000,000 or 1,500,000-2,500,000), a tenacity at least 5 g/den (e.g., at least 7 g/den) and a secant modulus at least 100 g/den (e.g. at least 125 g/den).

Abstract: A spinning solution of an acrylonitrile polymer is subjected to dry-wet spinning through an annular type spinneret having a non-perforated part, i.e. a part not formed with spinning orifices, extending from the outer periphery to the inner periphery. The spinneret has more than 3,000 spinning orifices, at the perforated part of the annular portion. The extruded fibers are then passed through a coagulation bath, and the coagulated fibers are then stretched. By this method, uniform acrylic fibers can be produced without causing quality unevenness and fiber defects due to uneven coagulation, filament agglutination, and fluctuation of the gap between spinneret lower surface and liquid surface of the coagulation bath.

Abstract: Processes for producing semipermeable membranes in the form of hollow fibers are disclosed including extruding a solution of a block copolymer including at least one hydrophilic polymer and at least one hydrophobic polymer while simultaneously injecting a gaseous or vaporous center medium into the center bore of the hollow fiber extrudate, including coagulating the extrudate so formed therefrom. The preferred process includes using air or the components of air as the center medium and employing a polyethyleneoxide-polycarbonate block copolymer to form the hollow fiber membranes.

Abstract: A process for the production of acrylonitrile fibers and filaments having a precise cross-sectional profile in which filament-forming synthetic polymers are dry-spun from a solution having a viscosity of at least 120 falling bass seconds, measured at 80.degree. C., or a viscosity of at least 75 falling ball seconds, measured at 100.degree. C. Such solution is dry-spun through one or more nozzles. The nozzle hole are of the profile nozzles being less than 0.2 mm.sup.2 and the lateral width being less than 0.17 mm.

Abstract: Extraordinarily low ranges of error, with respect to yarn adhesion and uniformity, in dry spinning yarns are achieved when the spinning gas in the upper part of the shaft blasts the yarns radially from the inside to the outside in an apparatus designed for this purpose, the velocity of the radial flow of gas, dirctly below the spinning nozzle, transverse to the running direction of the yarns and within a spacing of 10 mm from the nozzle, increasing from 0 to at least from 0.2 to 1 m/s.

Abstract: Mixtures of water with water-miscible solvent(s) containing suspended, emulsified and/or colloidal impurities are purified by contacting the water-solvent mixture with an at least partially open celled foam containing 1-75 weight percent active pulverulent additives. The liquid and solid phases are then separated. The active pulverulent additives which may be incorporated into the foam by means of a binder or by incorporation in the reactants used to form the foam include active coals, brown coal dust, peat, iron oxides and brown coal coke dust.

Abstract: Silica-containing acrylic and modacrylic fibres are obtained without spinning defects in that an aqueous silica sol is reacted with a silane and with a polar organic solvent, the sequence in which the two agents are added being optional, the water is distilled off in a vacuum at a temperature of at most 60.degree. C., the thread-forming polymer is then added in a quantity which is sufficient to form a spinnable solution and the solution is spun.

Abstract: A conductive fiber is made by an electroless plating process which is used in conjunction with a wet spinning process. The polymer must be catalyzed before the wet gel is collapsed. The resulting filament has a conductive region which is at least partially coincident with the polymer structure.

Abstract: An acrylic fiber precursor for high performance carbon fibers free of defects which comprises an acrylonitrile polymer containing at least 90% by weight of acrylonitrile and has a surface roughness of 2.0 to 3.0 with dense inner structure. from a solution comprising 24 to 27.5% of the acrylonitrile polymer is dry-jet wet spun into a coagulation bath consisting essentially of dimethylformamide or dimethylacetamide and having a bath temperature of 5.degree. to 25.degree. C.Carbon fibers obtained by carbonizing these precursor acrylic fibers have no fusion bonding or agglutination of filaments and exhibit high performance.

Abstract: Polyacrylonitrile (PAN) fiber of high strength (tensile strength.gtoreq.20 g/d) produced from a polymer composed mainly of acrylonitrile (AN) and having a weight average molecular weight not less than 400,000, and a method of producing said fiber characterized by a multistage stretching step and a drying step under particular conditions.

Abstract: Damage to the natural tone of acrylic fibres, produced according to a continuous dry spinning process, can be avoided if from 0.025 to 0.2% by weight of ethylene diamine tetra-acetic acid, based on the fibrous solids material, is added to the spinning solution.

Abstract: A process for producing a drawn product of a crystalline polymer having tenacity and high modulus, which comprises compressing a gel-like material prepared from a solution of a crystalline polymer in a solvent (i.e. a gel-like sheet material (A) consisting of gel-like particles of a crystalline polymer and a solvent which is prepared by cooling a solution of a crystalline polymer in a solvent, or a gel-like film material (B) which is prepared by casting a solution of a crystalline polymer in a solvent) at a temperature lower than the temperature at which the gel-like material is dissolved, whereby removing a part of the solvent contained in the gel-like material, and drawing the compressed material, preferably using a drawing die. The drawn product is particularly useful as a tension member for optical fiber cable.

Abstract: Polyacrylonitrile filaments and fibers may be obtained without interruption by spinning the spinning solution into a hot-air spinning duct, washing, drawing, crimping, preparing, steaming, drying cooling and, optionally, cutting at a take-off rate kept at 150 to 400 m/minute and for a tow weight of from 10 to 100 g/m when(a) the washing process is carried out in several stages on the countercurrent principle and a vibrating duct is used for transporting the spun tow through the washing process,(b) drawing is carried out before and/or after washing in a steam atmosphere at 100.degree. to 120.degree. C.,(c) crimping is carried out in an aerodynamic crimping unit using a hot, gaseous medium under a pressure of from 5 to 16 bars and at a temperature in the range from 50.degree. to 210.degree. C.