Spectrophotometic determination of the degree of esterification of cellulose xanthate in viscose

Conclusions The spectrophotometric method permits a rapid determination of the value of CS₂ for xanthate in viscose. The duration of such a determination is 20–30 min. The method is recommended for the analysis of viscose under production conditions and for investigational work.All-Union Research Institute for Synthetic Fibres (VNIIV). Translated from Khimicheskie Volokna, No. 5, pp. 71–72, September–October, 1969.     

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.     

Adaptive control system for the viscosity of viscose

Conclusions A structure and algorithm have been developed for an adaptive system for control of viscose viscosity in the manufacture of artificial fibres.The control system has been introduced into the ACS TP for viscose tire cord manufacture of the Svetlogorodsk Khimvolokno PO.Translated from Khimicheskie Volokna, No. 5, pp. 22–25, September–October, 1986.     

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.     

Connection between the supermolecular structure of viscose with characteristics of the cellulose and with the properties of fibres and films obtained

Conclusions -- The supermolecular structure of spinning solutions from viscose manufacturing operations in the Balakovskii Khimvolokno PO has been studied by the turbidity spectrum method.-- Multiple and paired correlation equations have been obtained for the parameters of viscose supermolecular structure and the characteristics of the cellulose and the physicomechanical characteristics of hydrocellulose fibres and films.Translated from Khimicheskie Volokna, No. 5, pp. 42–45, September–October, 1991.     

Stablization of tahe viscose in the manufacture of artificial fibres

Conclusions A structure and algorithm have been developed for fan adaptive system for stabilizing the composition of viscose in the manufacture of artificial fibres.This system has been introduced into the ACS TP for the manufacture of viscose tire cord at the Svetlogordsk Khimvolokno PO.Translated from Khimicheskie Volokna, No. 5, pp. 25–26, September–October, 1986.     

The filtration of viscose through granular materials

Conclusions 1. A criterial equation has been derived for the filtration of viscose through a granular bed, using the Reynolds number Re_p, taking account of the rheological properties of viscose.2. Based on treatment of the experimental findings, a particular form of the relationship Eu= (Re_p) is suggested for the case of viscose filtration through quartz.3. An analytical equation has been derived to determine the initial filtration rate of viscose through quartz.Second communication.Moscow Technological Institute. Translated from Khimicheskie Volokna, No. 2, pp. 31–33, March–April, 1969.     

Algorithm for controlling the hemicellulose content of working alkali

Conclusions Principles for solving the problem of stabilizing the hemicellulose content of working alkali for the process of continuous mercerization in viscose manufacture have been examined.A procedure has been developed for structure synthesis and evaluation of the parameters of a discrete control system for objects with technological feedback.An algorithm for controlling hemicellulose content of working alkali based on a combined discrete control system has been devised and has been realized in the ACS TP for manufacture of viscose tire cord in the Svetlogorodsk Khimovolokno PO.Translated from Khimicheskie Volokna, No. 5, pp. 20–22, September–October, 1986.     

Determination of the gel-particle and other contaminant content of viscose

Conclusions An advantage of the FS-112 type of analyzer as compared with other domestic instruments is the possibility of determining gel-particles and mechanical contaminants contained in a viscose, and of determining their disperse composition in five measurement ranges — from 5 to 500 µ.The use of this instrument permits one to investigate viscose quality in more detail, and to select filtration conditions appropriately.The procedure developed has good reproducibility and can be recommended for introduction in laboratory practice and manufacturing conditions instead of the Tsellosko-202 counter.It is inadvisable to carry out the determination of the content of gel-particles and other inclusions by the procedure described on unfiltered viscoses, since these viscoses contain much fibre and film, which may choke the instrument capillary.Translated from Khimicheskie Volokna, No. 5, pp. 38–40, September–October, 1987.     

Viscosity properties of concentrated viscoses

Conclusions The physico-chemical properties of viscose containing up to 15% -cellulose by wt. have been investigated.It has been noted that increasing the -content of viscose affects principally the viscosity of solutions, but shows up only a little in the other characteristics of the viscose.At -cellulose contents up to 13.5% by wt. viscoses retain homogeneity and can present immediate interest for technological processing on appropriate selection of such parameters as temperature and NaOH/-cellulose ratio.Translated from Khimicheskie Volokna, No. 5, pp. 45–47, September–October, 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.     

Operative control of the productivity of the chemical works in viscose plants

Conclusions The statement and principles of solution of the problem of controlling the productivity of the technological process of viscose manufacturing have been examined.An algorithm for control of the productivity of the chemical works has been worked out and realized in the ACS TP for the manufacture of viscose tire cord at the Svetlogorodsk Khimvolokno PO; this algorithm assures coordination of the loads of the xanthation and mercerization division with the planned mean daily output of the spinning division, with fulfillment of assigned requirements on change in level of intermediate reserves during the planned period.Translated from Khimicheskie Volokna, No. 5, pp. 34–36, September–October, 1986.     

Hydraulic design of viscose conductors for spinning machines

Conclusions 1. A method has been developed for the calculation of viscose conductors for solution input into spinning machines by the calculation of the travelling and transit flow rates. It has been shown that for calculation of solution flow in a viscose conductor it is necessary to calculate the effective viscosity of the viscose as otherwise a significant variation from the true value is possible.2. It was shown that for the calculation of the main pipeline and of the viscose conductors in the branch pipes there is a possibility of work irregularity of the monitoring pumps and it also indicated the work of the filter-fingers established in front of the spinneret.Fourth communication.Moscow Textile Institute (MTI). Translated from Khimicheskie Volokna, No. 3, pp. 27–29, May–June, 1969.     

Adaptive system for stabilizing viscose ripeness

Conclusions A control algorithm has been described for the process of viscose ripening, which is based on compensating for current perturbations and predicting their effect using an adaptive mathematical model of the process.The algorithm developed has been realized in the make-up of the ACS TP for viscose tire cord manufacture in the Svetlogorodsk Khimvolokno PO and in cellophane manufacture in the Kiev Khimvolokno PO.Translated from Khimicheskie Volokna, No. 5, pp. 26–29, September–October, 1986.     

Change in polydispersity of degree of esterification of cellulose xanthate during the process of viscose ripening

Conclusions A method of determining the polydispersity of the degree of esterification () of the cellulose xanthate in viscose has been proposed, plus an algorithm for calculating it.The change in density of distribution of in cellulose xanthate during viscose ripening over a period of 96 h at 16°C has been studied.It has been found that the dispersion in density of distribution of in cellulose xanthate continuously decreases during ripening.Translated from Khimicheskie Volokna, No. 1, pp. 18–21, January–February, 1989.     

Viscose fibres from hydroxyethylcellulose of low degree of substitution

Conclusions The effect of introducing small quantities of hydroxyethyl groups into cellulose (=6–10) on the structure and properties of various types of viscose fibres has been studied. The structure and properties of cord fibre and cord are not affected, but the properties of textile yarn deteriorate sharply. There is a significant change in the structure of polynosic fibre and in some of its properties: the brittleness is reduced, simultaneously with an increase in alkali solubility and swelling in water.All-Union Scientific-Research Institute for Synthetic Fibres (VNIIV). Translated from Khimicheskie Volokna, No. 4, pp. 55–57, July–August, 1969.     

Clean-up of industrial wastewater from viscose manufacturing on filters having a foamed polystyrene charge

Conclusions Basic technological parameters of the process of filtering industrial wastewater from viscose manufacturing on filters having a polystyrene charge have been determined.It is recommended to use filters with a foamed polystyrene charge in the clean-up units of the Kalinin, Cherkassk, and Ryazansk Khimvolokno Industrial Association and the Sibvolokno PO to attain the required degree of wastewater clean-up in mechanochemical clean-up units.Translated from Khimicheskie Volokna, No. 5, pp. 13–14, September–October, 1988.     

Matching the Composition of Viscose to the Composition of the Spinning Bath in Production of Viscose Fibre

The existence of optimality criteria for viscose and spinning bath compositions is advanced as a working hypothesis. The degree of preparation of viscose for spinning is expediently characterized not only by the ripeness index and viscosity, but also by the chemical composition: the ratio of sodium trithiocarbonate (TTC)/NaOH_fr. A ratio of 2.0-2.1 should be considered optimum. Specific conductivity on the level of 32-33 S·m^–1 is the criterion of spinning bath activity.     

Effect of urea on the properties of viscose

Conclusions Additions of urea to viscose lead to a small increase in density and ripeness index, and to a decrease in its viscosity.Urea in viscose does not enter into specific interactions with the components of the viscose and is not decomposed.The change in properties of viscose on increasing the urea content is explained principally by an effect of dilution of the polymer solution.The authors express their thanks to V. G. Kulichikhin for help in this work and for participation in discussing the results.Translated from Khimicheski Volokna, No. 1, pp. 24–26, January–February, 1986.     

Effect of carbon disulfide consumption on the basic properties of viscose prepared from radiation-modified cellulose

Conclusions -- The process of preparing viscose from radiation-modified cellulose using carbon disulfide in the range of 6–32% of the weight of -cellulose in the xanthation has been investigated.-- Equations have been given which describe the dependence of the degree of esterification of the cellulose xanthate, the ripeness index, the byproduct content, the viscosity, and the filterability of the viscoses on CS₂ consumption in xanthation within the range 6–32% by wt.-- It has been found that a decrease in consumption of CS₂ primarily affects the viscosity of the viscoses obtained, and then it affects figures which characterize the content of byproducts, degree of esterification of the cellulose xanthate, ripeness, and the filterability of the spinning solutions.Translated from Khimicheskie Volokna, No. 5, pp. 51–53, September–October, 1991.