An adaptive system of automatic control of the quality indices in the process of polyethylene terephthalate

Conclusions -- Principles for constructing an adaptive control system for qualitative indices of the polyethylene terephthalate synthesis process have been examined.-- A mathematical assurance of a control system for the basic technological stages has been developed.-- A control algorithm has been realized in the esterification stage of the synthesis process of an industrial unit, which ensures a degree of completion of the process within assigned limits.Translated from Khimicheskie Volokna, No. 5, pp. 48–49, September–October, 1990.     

Control of a batch process of polymer synthesis by the low-temperature polycondensation method

Conclusions A mathematical assurance for a control system for a batch nonstationary process of polyme synthesis has been developed which uses the principle of control with respect to perturbation, with adaptation of a mathematical model.The use of a two-loop scheme of adaptation of the mathematical model of the process in two-cycle formation of the addition of active monomer has been given a foundation.Operability of the mathematical model and of the control algorithm have been confirmed by analysis of manufacturing data.Translated from Khimicheskie Volokna, No. 5, pp. 32–34, September–October, 1986.     

Mathematical modeling and calculation of the spinning solution filtration process in the manufacture of man-made fibres

Conclusions A generalized filtration equation has been obtained, which permits one to carry out mathematical modeling of a broad class of filtration processes of spinning solutions of fibre-forming polymers; it has low values of the error in approximation.On the basis of the results of mathematical modeling, a procedure has been worked out for evaluating the complex mechanism of the filtration process, using which it is possible to carry out a comparative analysis of the experimental data and to take into account (quantatively) the effect of technological conditions on the filtration process.The extremeness of the behavior of the basic characteristics of filtration equipment as a function of change in filtration rate, which characterizes the operating regime of a filter, has been demonstrated.The use of the magnitude of specific costs as an optimicity criterion in designing and rational construction of filtration schemes is soundly based.Program provision has been devised for calculating and making an analysis of the characteristics of apparatus design in the stage of filtering spinning solutions of fibre-forming polymers using a computer for projected and operating man-made fibre manufacturing.Translated from Khimicheskie Volokna, No. 2, pp. 24–27, March–April, 1985.     

Mathematical modeling of synthesis processes for polymers which are prepared by the low-temperature polycondensation method

Conclusions A procedure has been proposed for the construction and identification of a mathematical model for the process of a nonequilibrium polycondensation.The method is applicable for the construction of a mathematical model and control algorithms for the control of a process for preparing a thermally resistant polymer.Translated from Khimicheskie Volokna, No. 2, pp. 8–11, March–April, 1985.     

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.     

System for automated design of equipment for the manufacture of nonwoven materials from polymer melts

Conclusions A system for automated design of equipment for the manufacture of filamentary nonwoven materials has been developed — the SNM SAD. The system has been realized on an SM 1420 computer.An interactive regime of the SAD operation is used; and theoretical and empirical mathematical models have been employed for the basic technological processes in the preparation of nonwoven material; imitative modeling and optimization based on mathematical methods of experiment planning have also been used.Translated from Khimicheskie Volokna, No. 4, pp. 10–12, July–August, 1989.     

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.     

A mathematical model of the oxidative degradation of alkali cellulose in pre-ripening chambers

Conclusions A theoretical study of the oxidative degradation of alkali cellulose in pre-ripening chambers has been conducted.A mathematical model of the process has been constructed which reflects the change in mean degree of polymerization and temperature of the alkali cellulose along the length of the chamber, with consideration of heat-exchange and hydrodynamic processes.The values of the kinetic and thermal constants of the mathematical model have been refined on the basis of experimental data, and its adequacy for the object has been established.Translated from Khimicheskie Volokna, No. 2, pp. 14–16, March–April, 1985.     

The preparation of fibrous anion-exchange resins based on a graft copolymer of polycaproamide-polyglycidyl methacrylate and polyethylene polyamine

Conclusions -- A mathematical model for the amination reaction of the PCA-PGMA graft copolymer has been constructed which adequately describes the process.-- The problem of optimizing the process of aminating the PCA-PGMA graft copolymer with polyethylene polyamine has been solved. The chemisorbents prepared at the optimum regime have an SEC of up to 3.7 meq/g.Translated from Khimicheskie Volokna, No. 5, pp. 34–35, September–October, 1991.     

Search for optimum regimes in the imidization of polyamido acid in solution

Conclusions -- A mathematical model of the process of imidizing a polyamido acid in the liquid phase has been developed using the theory of neighboring group effects.-- An identification of the model has been performed using the method of moments.-- The mathematical model of the imidization process of polyamido acids has been used to calculate optimum regimes for preparing polyimide fibres.Translated from Khimicheskie Volokna, No. 1, pp. 22–24, January–February, 1991.     

Basic principles in developing waste-free technology for regeneration of components from spent solutions in synthetic fibre manufacture

Conclusions A methodological approach is given to the development of a technological process for regenerating the components from spent technological solutions. As the object we have examined a very complex system containing an aprotic amide solvent, a monohydric alcohol, water, and a salt component — a chloride of an alkali metal or alkaline earth metal.Requirements have been formulated for heat- or heat-and-mass exchange processes for the preparation of chemical pure object regeneration products. Practical schemes have been examined for closed processes on regenerating components which assure low-waste technology conditions, and recommendations have been given for bringing them into a waste-free technological process.Translated from Khimicheskie Volokna, No. 2, pp. 52–54, March–April, 1989.     

Stability to the process of spinning a jet of polyacrylonitrile solution in dimethylformamide

Conclusions An experimental study of stretching resonance in spinning solutions of polyacrylonitrile in dimethylformamide has been performed, and conditions for stable spinning of these solutions has been determined.It has been shown that the mathematical model used to describe theoretically spinning process stability adequately describes this process only on the condition that the rheological characteristics are functions of lengthwise deformation rate and spinning conditions.Translated from Khimicheskie Volokna, No. 4, pp. 16–18, July–August, 1988.     

Systems for automating technological processes of synthetic fibre and yarn preparation

Conclusions -- Some basic special features in devising a panel-free technology in the manufacture of synthetic fibres and yarns have been examined.-- Some advantages of an approach based on parallel designing of the technological process and the control system over the traditional approach have been shown.-- The new methodical approach has found application in developing automation systems at a number of synthetic fibre and yarn manufacturing plants.Translated from Khimicheskie Volokna, No. 5, pp. 47–48, September–October, 1990.     

Some features of moisture exchange by carbon fibres

Conclusions A mathematical model for the moisture exchange of carbon fibres in an atmospheric medium has been proposed.The kinetics of moisture exchange by carbon fibres has been studied. Depending on atmospheric humidity, the dynamics of moisture exchange by carbon fibres is determined by a mechanism of activated, Knudsen, or free diffusion or by a combination of these.Diffusion coefficients have been obtained for the moisture which make it possible to carry out a calculation of the drying process and to select optimum conditions for storing carbon fibres.Translated from Khimicheskie Volokna, No. 1, pp. 36–37, January–February, 1990.     

Texturizing synthetic fibres with a stream of hot gas

Conclusions The features of the pneumotexturizing process for synthetic yarns have been examined in comparison with mechanical crimping. A mechanism has been suggested for crimp formation on elementary filaments in pneumotexturizing.Experimental dependences of the properties of the yarns obtained on the temperature of the working air stream have been given.Translated from Khimicheskie Volokna, No. 1, pp. 18–19, January–February, 1984.     

Analytical control of contaminating components in wastewater from viscose manufacturing operations

Conclusions The world working level of control of the composition of natural waters and wastewater has been analyzed.A mathematical model has been proposed which characterizes the level of environment-protective standardization and the tendency for its development.The information stream of national and international standards with respect to nomenclature and quality has been analyzed. Tendencies have been disclosed which coincide with mathematical calculations.A high completeness in standardization of procedures in performing measurements of the composition of natural waters and wastewater, orderliness in standardization, a tendency toward overall standardization, automatic, and instrumentation of standardized methods of performing measurements are characteristics of the leading countries in the environmental-protective respect (as applied to the needs to viscose manufacturing).The overall model of analytical control which has been made up in the leading countries in the environmental respect can be used in the man-made fibre sub-branch upon appropriate treatment.Translated from Khimicheskie Volokna, No. 6, pp. 21–26, November–December, 1988.     

Optimizing the processes of recovering dimethylacetamide and isobutanol in the manufacture of man-made fibres

Conclusions The process of recovering DMAc and IBA has been investigated using mathematical modeling.It has been shown that the use of a two-phase adsorption—desorption cycle is possible for recovering DMAc at an original concentration not over 4 g/m³ and for an initial IBA concentration not over 2 g/m³.Translated from Khimicheskie Volokna, No. 1, pp. 52–54, January–February, 1987.     

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.     

Some features of the heterophase emulsion graft polymerization of glycidyl methacrylate to polycaproamide fibre

Conclusions -- The special features of the graft polymerization of glycidyl methacrylate to polycaproamide fibre have been discovered. An anomalous effect of the copper compound and of hydrogen peroxide in the composition of the redox system on the rate of graft polymerization of glycidyl methacrylate has been found.-- The graft polymerization in the presence of the redox system Cu_c-H₂O₂ which has been examined is characterized by a high rate and high monomer conversion and takes place essentially without formation of homopolymer.-- The relationships which have been found indicate a high efficiency and an ecological cleanness of the graft polymerization process at hand.Moscow State Textile Academy. Translated from Khimicheskie Volokna, No. 5, pp. 14–16, September–October, 1992.     

Some algorithms for treatment of information in automatic control systems for technological processes

Conclusions Questions in the selection of optimum algorithms for filtration, extrapolation, and interpolation in an ACS TP have been examined.Procedures have been proposed for estimating optimum values for the sampling period and filter parameters from measured signal values.Results of this work have been introduced into the ACS TP for viscose tire cord manufacture at the Svetlogorodsk Khimvolokno PO.Translated from Khimicheskie Volokna, No. 1, pp. 24–27, January–February, 1987.