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.     

Some aspects of spinning fibres from fluorine-containing copolymers by melt extrusion

Conclusions The following special features have been found in spinning fluorine-containing fibres: a small length of the deformation zone and a high degree of preliminary orientation.The advantages of spinning fibres from CP TFE-E or CP TFE-PFAVE as compared with other thermoplast fluorinated monomers consist in a high stability and speed of spinning.Translated from Khimicheskie Volokna, No. 2, pp. 28–30, March–April, 1986.     

Analytical Calculation of Kinematic and Thermal Parameters of Fibres in Spinning from Polymer Melts

An analytical mathematical model of spinning was obtained in the condition of constant rheological forces over the spinning path with algebraic calculation equations for the speed, speed gradient, and fibre temperature. The qualitative behavior and quantitative values of the calculated quantities demonstrate the possibility of using the analytical expressions for calculating the kinematic and thermal parameters of fibres.__________Translated from Khimicheskie Volokna, No. 2, pp. 52–54, March–April, 2005.     

Change in structure of polypropylene during processes of fibre spinning by the high-speed method

Conclusions Conditions for preparing polypropylene fibres from polymers of various structural modifications, orientations, and crystallinities at spinning speeds of 1000–5000 m/min have been studied experimentally.The investigated fibres are characterized by a high degree of crystallinity and orientation of the crystalline regions.Depending on fibre spinning speed, a transition is observed through definite morphological structures — from spherulitic to a typical fibrillar structure, which is formed at very high spinning speeds.Translated from Khimicheskie Volokna, No. 6, pp. 47–49, November–December, 1989.     

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.     

A mathematical model of the aerodynamic method of spinning fibres from polymer melts

Conclusions The problem of spinning fibres from thermoplastic polymers by the aerodynamic method in the preparation of nonwoven materials has been formulated and realized on a computer.It has been shown that the character of change in rheological force and lengthwise velocity gradient over the spinning path length differs sharply from the corresponding quantities in the classical method of spinning polymer melts.Translated from Khimicheskie Volokna, No. 4, pp. 18–20, July–August, 1988.     

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.     

Structure formation in high-speed spinning of polyethylene terephthalate

Conclusions Commonness and differences in yarn structure formation by high-temperature and low-temperature stretching have been shown.Model concepts on the development of structure in high-temperature deformation during the process of high-speed yarn spinning have been examined.It has been found that, on changing the linear density of elementary filaments, the spinning speed, or the position of the lubricating device, the proportion of effective high-temperature and low-temperature deformations changes.Translated from Khimicheskie Volokna, No. 3, pp. 16–19, May–June, 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.     

Tube spinning of viscose fibres

Conclusions Tube spinning of viscose fibres makes it possible to reduce the hydrodynamic frictional resistance of the precipitation bath.The possibility is created of raising spinning speed, increasing the number of spinneret holes, and raising fibre quality.On use of tube spinning, questions of reducing gas contamination of the working zone and mechanizing spinneret replacement are solved more effectively.Translated from Khimicheskie Volokna, No. 2, pp. 8–13, March–April, 1986.     

A mathematical model of a nonstationary process of fibre spinning from polymer melts

Conclusions The nonstationary problem of fibre spinning from thermoplastic polymers has been formulated and realized on a computer.Solution of the problem makes it possible to model correctly not only the phenomenon of stretching resonance, but also the effect of technological disturbances on spinning instability.Translated from Khimicheskie Volokna, No. 4, pp. 45–47, July–August, 1986.     

Isothermal stretching of the jet of polymer melt in aerodynamic fibre spinning

Conclusions Equations have been obtained for determining the diameter of a polymer melt jet over the length of the isothermal section, which is the zone of spinning fibre by the aerodynamic method.A comparison of the results of calculations with experimental data shows that they agree satisfactorily.Translated from Khimicheskie Volokna, No. 2, pp. 18–19, March–April, 1988.     

Effect of the conditions of spinning of polyester fibres on the longitudinal velocity gradient

The velocity gradient changes as a function of the conditions of spinning PETP, and the value can increase from several tens to hundreds of units in the order LSS (low-speed spinning)—MSS (medium-speed spinning)—HSS (high-speed spinning). A combined increase in the longitudinal velocity gradient, orientation, and relaxation time is observed with an increase in the speed of spinning PETP. It was shown that crosslinking of PETP is determined by the character of the strain in the longitudinal velocity gradient field. The features and common points of spinning of PETP monofilament and complex fibre and their cross-linking in a longitudinal velocity gradient field were determined.All-Russian Scientific-Research Institute of Synthetic Fibres, Tver'. Translated from Khimicheskie Volokna, No. 5. pp. 30–33, September–October, 1996.     

Special features in spinning high-modulus viscose fibre of high linear density

Conclusions On transition to spinning 0.13–0.17 tex HMV fibres to 0.22–0.44 tex fibres, to maintain diffusion conditions in spinning, the H₂SO₄ content of the precipitation bath should be kept at a level of 70–75 g/liter or increased by no more than 1–2 g/liter. Process stability is achieved by reducing the spinning speed. However, the round cross-sectional form of the fibre is not retained, and its physicomechanical properties are diminished.A further rise in fibre quality may be attained by invreasing the -Cellulose content of the viscose to 7.5% by wt., with a simultaneous increase in the viscosity of the viscose to 250–300 sec.Translated from Khimicheskie Volokna, No. 4, pp. 28–29, July–August, 1989.     

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.     

Preparation of reinforced composite yarns based on polymer mixtures

Conclusions The possibility has been demonstrated of preparing self-reinforcing composite fibres on spinning the following mixtures from the melt: polycaproamide—polyoxymethylene; copolyamide—polyoxymethylene; or an ethylene—vinylacetate copolymer—polyoxymethylene, due to the formation of ultrathin polyoxymethylene fibres in the bulk of the other polymer on flow of the mixture melt. Because of the presence of microfibres, an increase in the orientation stretch ratio of the composite fibre is observed, plus a synergistic increase in its strength and initial modulus.In articles from polymer mixtures with a well-developed interfacial layer and a strong interaction of the components in it, the maximum reinforcement will take place only at a low (up to 10%) content of the disperse phase polymer. In the absence of a strong interaction, the maximum reinforcing effect is observed when there is a predominant formation of ultrathin fibres of continuous length by the disperse phase polymer.The presence of films decreases the rise in strength and modulus of the composite fibre to a greater extent than the presence of short fibres.Translated from Khimicheskie Volokna, No. 3, pp. 35–37, May–June, 1984.     

Adoption of block spinneret assemblies with an increased number of holes

Conclusions Use of BFK-28.5 block spinneret assemblies has made it possible to ensure the necessary level of regeneration of the fibre and process stability at a spinning speed of 27 m/min.As a result of this, a productivity of 25 metric tons/day has been attained for the PL-25-I flow line.Translated from Khimicheskie Volokna, No. 3, pp. 46–47, May–June, 1987.     

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.     

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.     

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.