Optimization of the spinning solution preparation process in the manufacture of polyvinyl chloride fibre

Conclusions The effect of spinning solution preparation parameters on the fibre preparation process and on the properties of polyvinyl chloride fibre have been studied using the experiment planning method.It has been found that the concentration and holding time of the spinning solution exert the greatest effect on the process of washing the fibre free of dimethylformamide.An optimization of the parameters of preparing a solution for polyvinyl chloride fibre production under manufacturing conditions has been carried out.Translated from Khimicheskie Volokna, No. 1, pp. 24–25, January–February, 1988.     

Preparation of ftorlon fibre filled with manganese dioxide

Conclusions The possibility of obtaining catalytic fibres by introducing the catalyst as a filler into the structure of Ftorlon fibre has been established.Sorptive properties of Ftorlon fibre spun in the absence of filler as a function of the amount of polyethylene glycol added to a spinning solution of the fibre-forming polymer and of the spinning conditions have been investigated, as well as the morphology of the surface of the modified Ftorlon fibre.It has been discovered that, by choosing the composition of the spinning solution and the conditions of spinning Ftorlon fibre filled with manganese dioxide, it is possible to obtain a fibre having a porous structure which ensures accessibility of the filler to reagents.Translated from Khimicheskie Volokna, No. 2, pp. 31–33, March–April, 1988.     

Heat- and mass-exchange in spinning acetate fibres

Conclusions The process of heat- and mass-transfer have been examined in the spinning of acetate fibre. A calculation of the heat- and mass-transfer coefficients and of the diffusion coefficient has been carried out.It has been found that the fibre being spun passes through four zones in the spinning tower. Zones I and II are characterized by a high rate of mass-transfer; in these zones, 70–75% of the acetone is evaporated from the fibre. In zones III and IV, the heat-exchange process is intensified; here the heat-transfer coefficient is 1.7 to 2.0 times less than in zones I and II.Translated from Khimicheskie Volokna, No. 6, pp. 23–25, November–December, 1985.     

Effect of surface-active substances on the fibre-forming process and properties of nitron fibre

Conclusions The effect of surface-active agents on the surface tension of polyacrylonitrile (PAN) spinning solutions has been studied.It has been found that introducing SAS into the precipitation bath increases fibre-formation stability. The use of SAS as modifying additives to the spinning solution and into the precipitation bath leads to an increase in the uniformity of spun fibre properties.The possibility of reducing the linear density of Nitron fibres on introducing SAS into the spinning solution and the precipitation bath has been demonstrated.Translated from Khimicheskie Volokna, No. 3, pp. 24–26, May–June, 1985.     

Diffusion processes in spinning polyacrylonitrile fibres

Conclusions -- It has been found that the diffusion coefficient of precipitant into polyacrylonitrile fibre being spun at 20°C is 0.8·10^–5 cm²/sec.-- The distribution of precipitant concentrations in fibre spun from solutions of polyacrylonitrile into an aqueous thiocyanate precipitation bath has been obtained.-- The extent of the polymer precipitation zone in a jet of spinning solution has been estimated.Translated from Khimicheskie Volokna, No. 5, pp. 6–8, September–October, 1990.     

Chemical changes in polyvinyl fluoride during the process of fibre-spinning

Conclusions The change in some properties of polyvinyl fluoride during the process of fibre spinning has been investigated.It has been found that during the process of converting PVF powder into fibre, the degree of polymer crystallinity plus its resistance to thermal and thermooxidative degradation is increased; depending on the spinning regime, the densities and physicomechanical properties of PVF fibres are different.Translated from Khimicheskie Volokna, No. 4, pp. 34–35, July–August, 1984.     

Structure of a biocatalyst fibre containing modified β-galactosidase

Conclusions A connection between the composition of the spinning solution intended for preparation of a biocatalyst fibre, the conditions of fibre spinning, and the porosity characteristics of the fibre structure has been established.The possibility of purposefully regulating the catalytic properties of a biocatalyst fibre by varying the fibre structure has been demonstrated.Translated from Khimicheskie Volokna, No. 1, pp. 21–23, January–February, 1989.     

Spinning of a chemisorptive sulfonic acid fibre

Conclusions Special features of spinning a fibre by the wet method from a copolymer based on acrylonitrile and sodium methallylsulfonate which are connected with dissociation and solvation of the sulfonate groups have been examined.It has been found that, to obtain a fibre with satisfactory physico-mechanical properties which assure processing into textile articles from a sulfonate-containing copolymer, it is necessary to carry out the spinning either into nonaqueous baths or into aqueous baths which contain lyophilic salts.Translated from Khimicheskie Volokna, No. 3, pp. 10–12, May–June, 1988.     

Determination of acid impurity content in spinning solution and in freshly spun fibre made from aromatic polyamides

Conclusions The spinning solution from the manufacture of fibre from an aromatic polyamide contains dissolved HCl in the free form and HCl bonded to functional groups of the polymer; the freshly spun fibre contains only bonded HCl.A procedure has been developed for determining the content of free and bound HCl in spinning solution and freshly spun fibre; it is based on titrating a sample of a specimen in a medium of dimethylacetamide containing 3% LiCl with an approximately 0.04-molar alcoholic KOH solution.Translated from Khimicheskie Volokna, No. 2, pp. 58–60, March–April, 1990.     

Spinning cellulose acetate fibres in a nitrogen stream

Conclusions Results of studies on the spinning of acetate yarn in a current of nitrogen, at elevated concentrations of acetone vapor in the vapor-gas mixture in the spinning tower, have been presented.It has been shown that when acetate yarn is spun under the indicated conditions, the physicome chanical properties of the fibre are improved and the residual acetone content of the freshly spun yarn is reduced.Translated from Khimicheskie Volokna, No. 1, pp. 28–29, January–February, 1984.     

Optimizing the process of filtering spinning solutions

Conclusions The question of optimizing the spinning solution filtration process with respect to a production criterion — the maximum gain in commercial production (profit) — has been examined.It has been shown methodically and experimentally that attainment of the maximum yield of fibre of highest quality as a result of increasing the cleanness of the spinning solution is attended with a deviation from the maximum profit.A procedure has been worked out, and specific example given, for calculating the optimum values of the filtration surface and charge density for typical manufacturing situations. It is recommended to use this procedure in plants which produce viscose, acetate, nitron, or other fibres.Translated from Khimicheskie Volokna, No. 6, pp. 8–12, November–December, 1985.     

Dry-spinning fibres from solutions of polymers in high-boiling solvents

Conclusion Dry spinning from polymer solutions in high-boiling solvents is used extensively for the production of polyacylonitrile, polyurethan, and thermostable fibres of various classes. The method possesses important economic advantages over wet spinning, i.e., the concentration of the spinning solution and the spinning speeds are higher, and solvent recovery is easier and more complete.The dry method is preferred for polyurethan fibre, polyacrylonitrile filament, and fibres based on poly-m-phenylene isophthalamide, polybenzimidazoles, polyamidoimides, and polyimides because it gives better physicomechanical fibre properties.The spinning speed for these fibres does normally exceed 300 m/min although speeds of 800–1000 m/min have been reported as practicable.The quality of the finished fibres is influenced to a significant extent by the configuration of the spinning equipment (i.e., the cabinet design and the method of distributing the gas-air flow) and by the substances added to the spinning solution (esters of phosphoric acid, organosilicon compounds, etc.).All-Union Scientific-Research Institute for Man-Made Fibres. Translated from Khimicheskie Volokna, No. 1, pp.11–17, January–February, 1976.     

Some features of spinning hollow fibres from polycarbonatesiloxane melts

Conclusions The following parameters have been determined as a result of calculations: fibre tension, solidification path length, and the change along the spinning path of the following: stretching stresses, speed, radius, wall thickness, and fibre temperature.It has been shown that, with increase in take-up speed, the length of the section of fibre deformation is reduced, varying practically proportionally to the flow rate of the polymer system.Stability of the process of spinning hollow fibres from polycarbonatesiloxane melts is assured within a narrow range of stretching force.Translated from Khimicheskie Volokna, No. 3, pp. 41–43, May–June, 1989.     

The role of fibre diameter in preparing a heat-bonding fibrous material

Conclusions The connection of the basic technological parameters of the spinning process with structural parameters has been established for heat-bonded fibrous materials.It has been shown that the decisive structural parameter which affects the service characteristics of heat-bonded fibrous materials to the greatest extent is the fibre diameter.An equation has been found which reflects the dependence of fibre diameter on technological spinning parameters, and which makes it possible to predict the operational properties of heat-bonded materials.VNIISV, Tver'. Translated from Khimicheskie Volokna, No. 2, pp. 37–39, March–April, 1992.     

Preparation of heat-stable polypropylene fibres and their properties

Conclusions A method has been developed for preparing a modified polypropylene fibre by spinning from a mixture of polypropylene and a small amount of a thermoplastic acrylonitrile copolymer which contains a functional group which forms intermolecular chemical bonds during the fibre preparation process.It has been shown that in the given method of modifying PP fibre, its heat resistance is raised by 40–50°K.Translated from Khimicheskie Volokna, No. 3, pp. 51–52, May–June, 1985.     

The problem of refining cellulose triacetate solutions with fibrous ion-exchange resins

Conclusions The process of cleaning up cellulose acetate spinning solutions and model solutions from traces of acid dyes with polyacrylonitrile fibre anion-exchangers has been investigated. Optimum conditions for carrying out the clean-up have been determined.It is recommended to use ion-exchange resin type PAN(2)cp-PEA, prepared using a polyamine preparation, to clean up the spinning solution.Translated from Khimicheskie Volokna, No. 5, pp. 16–17, September–October, 1985.     

Structure of polyurethane spinning solutions and its effect on properties of spandex fibre

Conclusions The supermolecular structure of solutions of polyurethane and of polytetramethylene ether glycol has been studied. It has been found that spinning solutions having a large content of gel-particles are obtained from a more structurized polytetramethylene ether glycol.Correlation analysis of the dependences of physico-mechanical fibre indices on parameters of the low-molecular compounds of spinning solutions has shown that the specific load and load at 300% extension vary directly proportionally to the concentration and inversely proportionally to the size of particles in the spinning solution, and shrinkage in hot water varies in the opposite way.Translated from Khimicheskie Volokna, No. 1, pp. 37–38, January–February, 1989.     

Effect of orientation stretch and of jet stretch on properties of viscose fibre spun into a bicomponent precipitation bath

Conclusions The effect of orientation stretch and of jet stretch on the technological process of preparing viscose fibre from viscoses containing added urea has been studied in spinning into a bicomponent precipitation bath containing sulfuric acid and sodium sulfate.It has been shown that increasing the air stretch to 30–40% while reducing the sulfuric acid content of the precipitation bath to 80–100 g/liter and reducing the jet stretch 8 to 20% helps to improve the properties of viscose fibre.Translated from Khimicheskie Volokna, No. 4, pp. 47–48, July–August, 1989.     

Causes of the appearance of adhesions in the formation of cuprammonium staple fibre

Conclusions 1. It has been shown that the content of ammonia in the spinning solution and the coagulation bath, the content of sodium sulphate in the coagulation bath, and the rate of its feed to the spinning unit affect the adhesivity of cuprammonium staple fibre.2. To decrease the number of adhesions in the fibre it may be recommended that the ratio of ammonia to cellulose in the solution should be kept between 0.48 and 0.50, the content of ammonia in the coagulation bath should be not more than 0.05 g/litre and that of sodium sulphate 1.2–1.5 g/litre, and the rate of feed of the bath should be 18–20 litres/min.We express our thanks to Prof. A. B. Pakshver for valuable advice in the performance of this investigation.Ivanov Chemical and Technological Institute (IKhTI); Shui Factory. Translated from Khimicheskie Volokna, No. 3, pp. 41–42, May–June, 1969.     

Increasing the linear density uniformity of yarn spun from an aggressive solution

Conclusions It has been found experimentally that to increase the uniformity of linear density of yarn spun from an aggressive spinning solution of 40–50 Pa·sec viscosity, it is necessary to use metering pumps of high output and to maintain a positive pressure difference of up to 1 MPa between the spinning solution pressure at intake and that at discharge from the pump.A new candle filter construction has been proposed for maintaining a positive difference between the spinning solution pressure at intake and at discharge.Translated from Khimicheskie Volokna, No. 1, pp. 40–41, January–February, 1986.