Modification of carpet grade texturized polycaproamide yarns

Conclusions It has been found that the introduction of Boramol-15 in amounts up to 3% by wt. in the -caprolactam polyamidation stage does not effect the rheological properties of the polycaproamide melt or the texture properties of the polyamide yarns, and, at the same time, ensures good antistatic and soiling properties.Addition of Boramol-15 increases the rate and equilibrium sorption level of dyes by a factor of 2 to 2.5 as compared with sorption of the unmodified specimens.The physico-mechanical and texturized properties of polycaproamide yarns modified with Boramol-15 do not differ from those of serially produced yarns; the modified yarns have good processing ability.Translated from Khimicheskie Volokna, No. 4, pp. 29–31, July–August, 1988.     

Properties of complex viscose yarns containing elementary filaments of different linear density

Conclusions Breaking loads and deformation properties of complex viscose yarns containing elementary filaments of different linear density have been studied.The change in structural nonuniformity over a cross-section of viscose textile filaments of different linear density has been quantitatively evaluated.Translated from Khimicheskie Volokna, No. 3, pp. 47–48, May–June, 1985.     

Chemical cross-linking of carboxymethylated viscose yarns

Conclusions The parameters of chemical cross-linking of yarns based on carboxymethylcellulose (CMC) and their physicomechanical properties depend on the concentration of the cross-linking agent — formaldehyde — the catalyst concentration, and also on the reaction temperature and time.A bound formaledhyde content of 0.5% by wt., in the form of methylene bridges in the make-up of CMC yarns, leads to a 31% increase in their strength in the wet state.Chemical cross-linking of CMC fibres with formaldehyde helps increase their resistance to biodegradation and correspondingly leads to a larger strength retention in living organisms.Translated from Khimicheskie Volokna, No. 5, pp. 18–20, September–October, 1989.     

Defectiveness of texturized yarns which have a matrix-fibrillar structure

Conclusions The PE content of a matrix-fibrillar yarn spun from a melt of a PCA-PE mixture exerts a significant effect on the formation of defects in this yarn.Yarn defectiveness has been evaluated from acid-resistance; the latter is somewhat reduced for untexturized yarns (as compared with the acid-resistance of yarns from pure PCA) and is considerably reduced for texturized specimens.During the texturizing process, defects of various depths and lengths are formed on the surface of matrix-fibrillar yarns due to breaking off of individual PE fibrils; the intensity of this phenomenon rises with increase in the concentration of PE in the PCA.Translated from Khimicheskie Volokna, No. 6, pp. 45–46, November–December, 1986.     

Carboxymethylated viscose yarns for surgical purposes

Conclusions In twisting complex yarns based on CMC, the plasticizing role of water is more noticeable than in twisting viscose yarns.The dependence of the breaking load of twisted CMC yarns on degree of twist has an extreme character, with a maximum at a twist of 150–200 twists/m.A number of medico-biological properties of reabsorbable surgical CMC yarns (capillarity, swellability, diameter, elasticity) depend on the degree of twist, a twist of 320–350 twists/m being optimal.Translated from Khimicheskie Volokna, No. 5, pp. 43–45, September–October, 1987.     

Effects of preliminary heat-treatment on properties of texturized carbimide yarns

Conclusions To obtain texturized carbimide yarns with high specific properties and satisfactory physico-mechanical properties it is necessary to subject them to heat-treatment at 140°C.A twist resistance of the texturized yarn greater than 60% is attained at a texturizing temperature 50°C higher than its preliminary heat-treatment temperature.Translated from Khimicheskie Volokna, No. 1, pp. 33–35, January–February, 1988.     

Interconnection between preparation parameters and the strength of texturized combined yarns

Conclusions The laws governing changes in breaking diagrams of texturized combined yarns as functions of technological parameters in their preparation have been studied.It has been found that, with increase in the amount of viscose fibre sheathing, a decrease in elastic modulus of the combined looped yarns takes place, plus an increase in the coefficient of utilization of the strength of the core yarn.Translated from Khimicheskie Volokna, No. 3, pp. 32–34, May–June, 1987.     

Development of equipment for production of carpet grade texturized polycaproamide yarns

Translated from Khimicheskie Volokna, No. 4, pp. 3–8, July–August, 1989.     

Change in properties of texturized carbimide yarns on additional heat treatment

Conclusions The heat-setting process in texturizing and supplementary heat-treatment affects the change in physicomechanical and specific properties of low-extensibility carbimide yarns.It is recommended to carry out supplementary heat-treatment of a highly-extensible carbimide yarn at a heating chamber temperature of 120–125°C.Translated from Khimicheskie Volokna, No. 6, pp. 35–36, November–December, 1985.     

粘胶纤维及其浸胶帘布的性能与应用

主要介绍国内外粘胶纤维的生产现状及人造丝帘线的特殊性能。人造丝帘线断裂强度比棉帘线高,断裂伸长率较低,模量高,几乎不存在干热收缩,尺寸稳定性极佳,而且耐热性能较好,浸渍处理较容易,是制造高性能轿车子午线轮胎的优良骨架材料。     

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.     

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.     

Expenditure of heat energy in drying viscose textile yarns

Conclusions It has been found that the thermogravimetric analysis method is applicable for determining the expenditure of thermal energy in desorbing moisture from hydrocellulose textile fibres; it gives a quantitative evaluation of the fractional composition of the water sorbed by the yarns and of its bonding energy with the yarn matrix.The change in consumption of heat energy at various extents of drying of freshly-spun viscose textile yarns has been studied.It has been found that extensive drying of yarns, to a moisture content significantly lower than the conditioned values, that is, overdrying, requires elevated, unjustified expenditures of heat energy.Translated from Khimicheskie Volokna, No. 4, pp. 43–44, July–August, 1987.     

Measurement of the propagation rate and damping rate of ultrasound in kapron texturized yarns

Conclusions The effect of molecular orientation and of tension in the specimen on the propagation velocity and absorption coefficient of longitudinal ultrasonic waves has been investigated with the aid of an acoustical method.The dependences found for the rate of propagation and the absorption coefficient of ultrasound have made it possible to analyze the mechanism of sound passage through a specimen as the fibre is straightened out.A relationship has been found between the change in rate of propagation and the damping coefficient of ultrasound in the process of molecular orientation.Translated from Khimicheskie Volokna, No. 5, pp. 35–37, September–October, 1983.     

Some special features in drying ordinary viscose textile yarns

Conclusions On machines for continuous spinning, finishing, drying, and twisting of viscose textile yarns without intermediate conditioning, the most favorable yarn moisture range is 10–13%; this ensures optimum physicomechanical indices and twist uniformity.In conductive-convective drying of viscose textile yarns which are in the drawn state, evaporation of moisture from the interfiber space takes place more slowly, the larger the number and the less the linear density of the elementary filaments in the complex yarn.Translated from Khimicheskie Volokna, No. 1, pp. 39–41, January–February, 1985.