Use of an electrical current to warm viscose

Conclusions The possibility of using an a.c. current of industrial frequency to warm viscose has been investigated. The action of the electrical current on physicochemical indices of the viscose during the process of warming has been studied. The viscosity, ripeness, and degree of esterification of the viscose are practically unchanged during the warming process.It has been found that a homogenizing of the viscose takes place under the action of an electrical current, thanks to this, preparation of the viscose for spinning, that is, filtration, can be facilitated.Translated from Khimicheskie Volokna, No. 1, pp. 36–37, January–February, 1987.     

Use of diluted viscose waste in the process of preparing complex yarn for aircraft fabrics

Conclusions The possibility has been established of using dilute viscose wastes in the process of preparing a spinning solution for spinning complex viscose yarns which are used in the manufacture of aircraft fabrics.Empirical equations have been obtained for calculating the change with time of ripeness indices and of free NaOH content of viscoses having an -cellulose concentration of 5.0–8.4% by wt., plus calculated dependences which ensure determining the optimum ripeness index for spinning for viscoses which have been diluted in the range indicated.It has been shown that, with decrease in -cellulose and NaOH content of the spinning solution, the stiffness of complex viscose yarn is increased.Translated from Khimicheskie Volokna, No. 3, pp. 48–50, May–June, 1986.     

Special features in spinning fine viscose textile yarns

Conclusions Conditions which assure stability of the process of spinning a complex viscose yarn with an increased number of elementary filaments have been determined.It has been shown that stability of the process of spinning complex viscose textile yarn of 13.3 tex linear density with an increase in number of elementary filaments (>60) is increased on reducing the jet stretch, reducing the diameter of the spinneret holes from 0.09 to 0.06–0.05 mm, and bringing the distance between them from 1.4 to 0.5 mm.Translated from Khimicheskie Volokna, No. 3, pp. 39–40, May–June, 1984.     

Effect of electromagnetic treatment of viscose on stability of the spinning process and quality of technical yarn

Conclusions The effect of electromagnetic treatment of viscose during spinning on the stability of yarn preparation and quality of the final viscose yarns has been studied.It has been shown that electromagnetic treatment of viscose permits one to increase yarn strength, resistance to repeated deformation, and shear modulus, to increase the degree of orientation of the polymer macromolecules in the yarn, and to reduce its degree of swelling.It is recommended to carry out electromagnetic treatment of the viscose directly on the spinning machine, before delivery of the viscose to the spinneret.Translated from Khimicheskie Volokna, No. 4, pp. 39–40, July–August, 1989.     

Increasing the dyeing uniformity of viscose textile yarn

Conclusions The possibility of significantly raising the dyeing uniformity of viscose textile yarn by activating the cellulose and by selecting technological spinning parameters which ensure maximum yarn shrinkage before its arrival at the centrifuge has been shown.It has been found that, with increase in the ability of the freshly spun yarn to shrink, its dyeing uniformity is reduced.The dyeing uniformity of viscose yarn prepared by the centrifugal method can be raised by changing its shrinkage on the spinning machine during the spinning process, by activation of the cellulose, and by choosing a precipitation bath which is very suitable for spinning viscose yarns from activated celluloses.Translated from Khimicheskie Volokna, No. 2, pp. 41–42, March–April, 1984.     

Role of precipitation bath components in the manufacture of viscose fibres

Conclusions An analysis has been made of data on structure formation processes in spinning viscose fibres and of the connection of the primary structure with the properties of the finished fibres and yarns.It has been shown that the attainment of high physicomechanical and operational properties of viscose fibres is possible by preventing premature crystallization of the cellulose in the freshly-spun gel-fibre.Retardation of the cellulose crystallization process in spinning viscose fibres is advisably effected as a result of reducing the activity of water in the precipitation bath.Translated from Khimicheskie Volokna, No. 1, pp. 8–13, January–February, 1986.     

Effect of mixing viscoses with different ripeness indices on the properties of a mixture of viscoses and high-modulus viscose fibre

Conclusions A mixture of viscoses with various ripeness indices will go into an equilibrium state on keeping for about 3 h.To calculate the ripeness index of a mixture of viscoses, it is possible to use empirical formulas, starting from the ripeness indices of the components.In contemporary methods of preparing viscose for spinning, a mixture of viscoses with a wide distribution in ripening times is delivered.Preparation of viscose for spinning, with return of part of the viscose from the first and second filtrations to the mixer, makes it possible to raise the stability of maintenance of the ripeness index of the vicose which is delivered to spinning, and to solve more rationally the problem of viscose recovery in recharging the filter presses.Translated from Khimicheskie Volokna, No. 3, pp. 31–33, May–June, 1983.     

Homogenization of viscose under the action of an alternating electromagnetic field

Conclusions A method of homogenizing viscose using an alternating electromagnetic field has been suggested.Homogenization of viscose by this method is advisably carried out at an alternating field strength of 50 kA/m, immediately before spinning on the spinning machine.Translated from Khimicheskie Volokna, No. 6, pp. 33–34, November–December, 1988.     

Electric viscose warmer

Conclusions An apparatus has been devised for preheating viscose before deaeration, using an electric current of industrial frequency.The use of this apparatus will make it possible to significantly intensify the viscose heating process, while simultaneously improving viscose quality.Siberian Technological Institute. Translated from Khimicheskie Volokna, No. 2, pp. 16–17, March–April, 1987.     

Spinning viscose technical yarn into a bicomponent precipitation bath

Conclusions -- The possibility has been demonstrated of preparing viscose yarn by the centrifugal method from a viscose containing additions of urea by spinning into a bicomponent precipitation bath containing sulfuric acid and sodium sulfate.-- Optimum conditions for spinning viscose yarn have been established: a sulfuric acid content of 115 g/l in the precipitation bath, a urea content of 2.5% based on weight of -cellulose in the viscose, and an orientation stretch of 22%.-- Specimens of viscose yarn having a linear density of 13.3 tex have been prepared with a relative breaking load of up to 19 cN/tex, an elongation at break of 17–19%, and a mean squared deviation in dyeing nonuniformity of 0.8–1.0.Translated from Khimicheskie Volokna, No. 4, pp. 33–34, July–August, 1990.     

Intensification of ripening of viscose with the aid of an optimization equation for the process

Conclusions It has been shown that in the intensification of the ripening process of viscose the optimum temperature curve, which allows viscose to be obtained prior to spinning with certain values of ripeness and rate of its change, there are two periods corresponding to heating and cooling of the viscose. A method has been described for determining the optimum temperature curve with the help of an ACM. We have dealt with a definite production situation for which tables have been calculated and formulae obtained, which for certain initial and final values of the ripeness and temperature of the viscose allow a determination of the optimum temperature—time conditions for the ripening process to be made.All-Union Synthetic Fibre Research Institute (VNIIV). Moscow Institute of Chemical Machinery (MIKhM). Translated from Khimicheskie Volokna, No. 3, pp. 22–24, May–June, 1969.     

Effect of urea additions on structure formation during the separation of hydrocellulose from viscose

Conclusions It has been shown by electron microscopy that the formation of two types of structure is possible on spinning model films from viscose into precipitation baths containing additions of urea: finely heterogeneous and cellular.The suggestion has been made that additions of urea to the precipitation bath retard viscose gelation processes.Translated from Khimicheskie Volokna, No. 4, pp. 25–26, July–August, 1986.     

An automatic nephelometric determination of the ripeness of undelustered viscose

Conclusions A method for automatic determination of viscose ripeness is based on nephelometric titration of a viscose sample with an ammonium sulfate solution having a concentration of 500 g/liter.The method has passed through pilot plant tests on undelustered viscoses going to spinning.Translated from Khimicheskie Volokna, No. 5, pp. 56–57, September–October, 1983.     

Processing sulfate viscose cellulose prepared using oxygen in bleaching

Conclusions -- Two lots of cellulose, from pine wood and from larch, have been developed; these were treated in the first stage of bleaching with oxygen in alkaline medium instead of by chlorination, under experimental conditions.-- From a preliminary evaluation, the process of viscose preparation and preparation of the viscose for spinning under experimental conditions took place without significant deviations from the accepted technological regime. Higher technological indices of the viscose from pine cellulose were noted.-- The process of spinning viscose fibre from experimental lots of viscose from larch wood and from pine took place in a stable fashion; no clogging of the spinnerets was observed.Translated from Khimicheskie Volokna, No. 5, pp. 17–19, September–October, 1990.     

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.     

Spinning viscose textile into a precipitation bath containing zinc and aluminum

Conclusions A viscose textile yarn was been prepared by spinning viscose into a zinc-aluminum-containing precipitation bath.Yarn elongation is increased with increase in zinc sulfate content and with decrease in the aluminum sulfate content of the precipitation bath.Jet stretch increases strength and reduces yarn elongation.Yarn strength and elongation increase with rise in viscose ripeness.Translated from Khimicheskie Volokna, No. 3, pp. 44–46, May–June, 1988.     

Constructional features of machines for making man-made fibres from solutions

Conclusions A series of machines has been developed for the manufacture of viscose textile yarn, viscose technical yarn, polyacrylonitrile fibre, and so on.The new units of these machines for spinning yarns from solutions are spinning units with a U-shaped tube, cascade washing, a spindle with tension regulation by use of annular permanent magnets, mirror adjustment of yarns in adjacent sections, and a take-up and winding mechanism with a mobile bobbin.Thanks to the application of these units, an increase in machine productivity has been assured, plus an improvement in the physico-mechanical indices of the product produced.Translated from Khimicheskie Volokna, No. 3, pp. 8–11, May–June, 1989.     

Resources for improving the quality of viscose textile yarns

Conclusions The important trends in raising the quality of viscose textile yarns are increasing the uniformity of the viscose and stabilizing spinning and finishing conditions.An increase in viscose unformity is attained by correcting the technological stages in its preparation, improving the apparatus design of the purification process, and "leveling out" the viscose with respect to ripeness, and so on.Elimination of defects in technology, optimization of jet stretch, spinning speed, and tension in the yarn during orientation stretch will make it possible to reduce breakage due to the presence of nap and to improve yarn runnability in textile processing.This work was performed under the direction of Professor M. P. Nosov.Translated from Khimicheskie Volokna, No. 1, pp. 7–10, January–February, 1985.     

Kinetics of the decomposition of cellulose xanthate in spinning viscose films into sulfuric acid precipitation baths

Conclusions Rate constants for the decomposition reactions of cellulose xanthate have been determined in spinning viscose films into sulfuric acid baths having acid concentrations of 100–1100 g/liter.The data obtained can be used to determine technological parameters in spinning fibres with assigned physico-mechanical characteristics.Translated from Khimicheskie Volokna, No. 5, pp. 37–38, September–October, 1987.     

Effect of alkaline earth metal or iron contaminants on properties of viscose

Conclusions The effect of salts of alkaline earth metals and iron on the physico-chemical indices of viscose — viscosity, ripeness, and filterability — has been investigated.In amounts which exceed the content allowed by the All-Union State Standard in viscose by a factor of 3–4, calcium and magnesium ions do not cause a significant impairment in the physico-chemical indices of the viscose.Even at a content of 28 mg/liter, the presence of trivalent iron salts in a viscose causes a sharp impairment in its filterability, especially on prolonged ripening.Strict control of the trivalent iron content of viscose during the process of preparing it for spinning is necessary.Siberian Technological Institute. Translated from Kimicheskie Volokna, No. 2, pp. 17–18, March–April, 1987.