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.     

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.     

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.     

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.     

Effect of technological spinning transitions on the properties of nickel-containing nitron fibre

Conclusions The effect of technological spinning transitions on the properties of an electrically-conducting metallized Nitron fibre has been investigated.It has been shown that in mechanical crimping the mechanical and electrically-conducting properties of a nickel-containing fibre are considerably impaired. During the spinning process, a considerable leveling out of the nickel content of the fibre and of its electrical resistance takes place.Processing of the nickel-containing fibre should be carried out with elimination of the mechanical crimping process. Thereupon the change in fibre properties takes place mainly during the process of preparing the combed lap.Translated from Khimicheskie Volokna, No. 5, pp. 39–40, September–October, 1985.     

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.     

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.     

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.     

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.     

Operative analysis of the stability of a spinning process based on methods of sample recognition

Conclusions An algorithm has been developed for operative analysis of the stability of the spinning process which is based on methods of sample recognition.A type program assurance has been recommended for use in the ACS TP for man-made fibre plants.Translated from Khimicheskie Volokna, No. 5, pp. 36–38, September–October, 1986.     

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.     

Resonance and fibre formation in the process of spinning melts of flexible-chain polymers

Conclusions The reason for onset of the polymer jet stretch resonance phenomenon during the spinning process has been found.A mechanism for the uniaxial stretching of a jet of viscoelastic liquid under conditions of fibre stretching resonance has been proposed.Some features in the spinning of a polycaproamide melt have been determined.This article was published to stimulate discussion.Translated from Khimicheskie Volokna, No. 1, pp. 24–26, January–February, 1990.     

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.     

Calculation of Filtration Throttling of Liquefied Gas with Evaporation

The throttling of a vapor–liquid mixture in porous filters of different design is mathematically described using filtration, thermodynamic, and heat- and mass-transfer equations, and an example of describing this process for carbon dioxide is presented.     

Laws governing the process of spinning isotropic pitches

Conclusions -- A procedure has been developed for calculating the specific volume of the flowing zone of fibre in spinning from the melt.-- The unequivocal connection between the specific volume of the flowing zone of spun fibre and the strength of the final fibre from pitches indicates that to attain higher strength, it is necessary to create more severe conditions for fibre cooling.-- It has been found that fibres from pitches with a softening point above 200°C are more sensitive to fluctuations in parameters of the spinning process.VNIIPV. Translated from Khimicheskie Volokna, No. 3, pp. 41–42, May–June, 1991.     

Effect of aerodynamic spinning parameters and polymer properties on fibre diameter

Conclusions On the basis of theoretical calculations by a mathematical model of the process of aerodynamic spinning of polymer melts, whose adequacy has been established from experimental data, the sensitivity of final fibre diameters to change in technological spinning parameters and on the thermophysical and rheological properties of the polymer has been determined.It has been shown that among the factors which most significantly affect the final fibre diameter are the velocity of air movement in the ejector, the polymer flow rate, the temperature of the melt, the density of the melt, the viscosity anomaly, and the activation energy of viscous flow.Translated from Khimicheskie Volokna, No. 5, pp. 37–39, September–October, 1988.     

Modification of polyacrylonitrile fibre with hydrolyzed wastes

Conclusions Principles governing the alkaline hydrolysis of wet Nitron fibre waste and their solubilities in 51.5% aqueous sodium thiocyanate solution have been studied. It has been found that the best solubility is attained at an SEC of 0.17–0.20 meq/g. The solutions obtained on addition of these wastes are characterized by reduced viscosity, better filterability, and a reduced gel-particle content.It has been found that stable spinning and preparation of fibre with better physicomechanical characteristics are achieved when 5% by wt. of the hydrolyzed products is added to the spinning solution.Translated from Khimicheskie Volokna, No. 1, pp. 10–11, January–February, 1989.     

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.     

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.     

Wet spinning of asymmetric hollow polysulfone fibres by the double spinning bath method

The possibility of fabricating an asymmetric hollow fibre from polysulfone in a one-stage process with the double spinning bath method was demonstrated. A correlation was established between the quality of the selective layer and the value of the diffusion coefficient of the solvent in the precipitant.Russian Institute of Chemical Technology, Moscow. Translated from Khimicheskie Volokna, No. 6, pp. 24–26, November–December, 1993.