Preparation and properties of looped viscose-kapron yarns

Conclusions The method of yarn texturizing with an air stream is universal: it permits one to obtain looped yarns both from natural fibers, and also from thermoplastic or nonthermoplastic man-made yarns. The main advantages of this method are the possibility of processing yarns over a broad range in linear density, a high texturizing speed, and maintenance of the physicomechanical properties of the original yarns.Using aerodynamic texturization, one can produce combined yarns which have such specific properties as incombustibility, electrical conductivity, antistatic behavior, etc.The use of yarns which have been texturized by the aerodynamic method will make it possible to enlarge the assortment of articles produced by the textile and jersey industry.Translated from Khimicheskie Volokna, No. 1, pp. 25–28, January–February, 1985.     

Some special features in texturizing complex Karbimid yarns

Conclusions The effect of the orientation stretch ratio of complex Karbimid yarns on their physicomechanical properties has been examined.It has been found that, to increase the ability of complex Karbimid yarns to undergo texturizing, it is advisable to use a yarn with a degree of orientation stretch of 600%.Translated from Khimicheskie Volokna, No. 1, pp. 32–33, January–February, 1984.     

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.     

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.     

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.     

Effect of pneumotexturizing on surface topography of polyethylene terephthalate and viscose yarns

Conclusions A classification of the basic types of defects in the surface of viscose yarns and yarns from polyethylene terephthalate which arise as a result of actions which take place during the pneumotexturizing process has been made.A qualitative estimate of the density of defects agrees with data on the strength characteristics of yarns which have been subjected to texturizing at various fibre movement speeds and air pressures in the nozzle of the aerodynamic device.Translated from Khimicheskie Volokna, No. 4, pp. 28–29, July–August, 1988.     

A study of the high-speed spinning process for polycaproamide complex yarns

Conclusions -- The basic laws governing the effect of spinning conditions on the properties of PCA yarns have been investigated. It has been shown that in distinction to spinning monofilaments, in high-speed spinning of complex yarns, additional factors appear by use of which it is possible to effectively control the properties of the yarns obtained.-- It has been found that the site of disposition of the aqueous lubricant in the high-speed spinning PCA yarns exerts a fundamentally different action on the breaking elongation of the yarns and on their structure, depending on the linear density and the number of elementary filaments in the complex yarn; however, it does not change the character of this dependence on the breaking strength of the yarn.-- Under otherwise equal conditions, a lower disposition of the lower lubricating device helps in obtaining complex PCA yarns which have a larger breaking strength and a lower elongation.Translated from Khimicheskie Volokna, No. 1, pp. 19–21, January–February, 1991.     

A combined process for double-twisting and heat-treating textile grade polyester yarn

Conclusions The use of a technological scheme which combines the processes of twisting and yarn heat-treatment makes it possible to intensify the process of textile grade polyester yarn manufacture as a result of shortening the series of textile-technology steps.The scheme permits one not only to set the twist well, but also to regulate the basic physicomechanical properties of the yarns over a wide range.By using the proposed technological scheme, depending on the assigned degree of deformation, one can obtained twisted yarns with a shrinkage of 1–2% at an initial elastic modulus up to 20 MPa.Translated from Khimicheskie Volokna, No. 6, pp. 32–33, November–December, 1984.     

Investigation of some specific properties of bulk-looped yarns by the acoustical method

Conclusions The principles for change in certain acoustical characteristics of bulk-looped yarns as a function of the load straightening out the yarn have been demonstrated.It has been found that the core yarn is the channel for propagation of ultrasonic waves.The rate of ultrasound damping can characterize certain specific properties of bulk-looped yarns and thereby help optimize the technological process for preparing them.Translated from Khimicheskie Volokna, No. 1, pp. 33–34, January–February, 1986.     

Improving the properties of fabrics as a result of the use of viscose-polyamide yarns

Conclusions An increase in the viscose yarn sheathing in combined loop yarns leads to an improvement in the hygienic properties of fabrics made from them.The properties of viscose-polyamide looped yarns permit one to use them in the assortment of yarns for shirting or blouse purposes. This trend in the use of looped yarns is very promising.The fabrics developed have an agreeable silkiness and high service properties, and they conform to contemporary style trends.Translated from Khimicheskie Volokna, No. 2, pp. 35–37, March–April, 1987.     

Structure and properties of dyed polypropylene yarn containing an addition of chemically colored low-molecular polycaproamide

Conclusions The thermal properties of PP yarns have been studied by determining their weight loss on heating. It has been shown that, by comparison with unmodified PP yarn, yarns containing an addition of chemically dyed LMPCA have improved thermal stability.Addition of chemically dyed LMPCA in the spinning of PP yarn leads to an increase in mean crystallinity and a decrease in the average size of yarn crystallites after jet stretch. The existence of two morphological forms of supermolecular structure has been shown by the electron microscopy method: spherulitic and oriented along the yarn axis.Translated from Khimicheskie Volokna, No. 6, pp. 20–21, November–December, 1986.     

Properties of Textured Yarns of Low Linear Density by Commercial Package Layers

The effect of the structure of commercial packages on the properties of textured yarn of low linear density is investigated. The possibility of using commercial packages with textured yarns of low linear density weighing 2.5 kg for 1.67 tex yarn, 3 kg for 2.2 tex yarn, and 4 kg for 3.3 tex yarn is established.__________Translated from Khimicheskie Volokna, No. 1, pp. 42–45, January–February, 2005.     

Yarn spinning stability from a cellulose triacetate melt

Conclusions In spinning yarns from a cellulose triacetate melt on a unit with a heatable spinneret, it is possible to calculate spinning parameters which ensure obtaining a yarn having a low degree of nonuniformity, both with respect to linear density and also in physicomechanical properties.The smaller the diameter of the spinneret holes, the greater the uniformity and the higher the physicomechanical properties of the yarn.Translated from Khimicheskie Volokna, No. 6, pp. 29–30, November–December, 1985.     

Laws governing the stretching of preliminarily oriented polyacrylonitrile yarn

Conclusions Boundaries for the transition of polyacrylonitrile into the glassy state have been determined in coordinates of temperature vs velocity of yarn movement through heater.An analysis is given of the physico-mechanical properties of yarns which have been drawn to various extents under conditions which differ considerably from the point of view of the relaxation behavior of the material.It has been shown that the properties of yarns having various degrees of stretch are close under conditions which correspond to a single isopiest. The maximum stretch ratio under conditions which correspond to a single isopiest increase as the temperature and rate of yarn movement are reduced.Translated from Khimicheskie Volokna, No. 4, pp. 24–26, July–August, 1988.     

Effect of a plasticizer on the properties of texturized diacetate yarns and their preparation on single-process machines

Conclusions Diacetate texturized yarns with a stable twist have been prepared on single-process machines with a false-twist mechanism.Yarn texturizing was carried out at 80–100°C in the presence of a plasticizer, whose role was filled by water; the process occurred in the zone of softening and partial viscose-flow state of the polymer.Translated from Khimicheskie Volokna, No. 3, pp. 45–47, May–June, 1983.     

Hydrodynamic stability of yarn spinning from a melt of flexible-chain polymers

Conclusions Empirical relationships have been obtained which describe satisfactorily the effect of basic spinning parameters on nonuniformity in the diameter of the undrawn yarns; these make it possible to calculate optimum parameters which ensure an assigned level of yarn nonuniformity in diameter.It has been found that increasing the melt viscosity decreases the region of stable spinning.A connection has been found between nonuniformity of the undrawn yarn and the strength of the finished yarn: the strength of the drawn yarn is increased proportionately to the decrease in nonuniformity of the undrawn yarn in its diameter.Translated from Khimicheskie Volokna, No. 5, pp. 16–18, September–October, 1984.     

Properties of acetate yarns having an increased content of elementary filaments

Conclusions A process has been developed for preparing 11/32 and 16.6/38 tex complex acetate yarns. Thereupon the yarn strength is increased by a factor of 1.2, and the resistance to repeated bending by a factor of 1.2–1.4.Processing acetate yarns having an increased content of elementary filaments in the complex yarn in textile industry plants has given good results.Translated from Khimicheskie Volokna, No. 4, pp. 27–28, August–July, 1989.     

Man-made fibres for carrets. Tendency in development

Conclusions The main direction of world development in the manufacture of man-made carpet yarns is modification of existing yarns with the purpose of improving the consumer properties of carpets — soil-repelling or soil-masking, antimicrobial, antistatic, or increasing yarn bulk, improving dyeability, resistance to ignition, etc.Reinforced carpet yarns and thread based on various combination of man-made fibres and complex yarns are finding steadily greater use in the manufacture of carpets.A new type of floor covering has appeared — carpet sheets, which are produced mainly by the tufting method at present.Translated from Kimicheskie Volokna, No. 5, pp. 18–23, September–October, 1987.     

New fibres prepared from cellulose-aqueous solution of sodium hydroxide systems (review)

The following basic conclusions were drawn from the published data examined; cellulose treated in steamblast conditions can form solutions and gelling pastes in an aqueous solution of sodium hydroxide; the solubility of cellulose in aqueous sodium hydroxide solution is primarily a function of the intramolecular bonds in the cellobiose unit with constant DP; intramolecular bonds are most efficiently broken in steamblast treatment in the cellobiose unit of cellulose I and cellulose III; monofilaments and yarns were obtained from solutions and gelling pastes of cellulose in aqueous sodium hydroxide solution; the physicomechanical properties of the monofilaments and yarns obtained from solutions and gelling pastes of cellulose in aqueous sodium hydroxide solution are still significantly lower than these indexes for viscose textile yarn.All-Russian Scientific-Research Institute of Polymer Fibres. Mytishchi. Translated from Khimicheskie Volokna, No. 2, pp. 11–14, March–April. 1996.     

Properties and application of Ovilan-2 texturized viscose yarns

Conclusions Ovilan-2 texturized viscose yarn has satisfactory physicomechanical characteristics, whose uniformity is improved on doubling two or more yarns.The high-bulk structure of Ovilan-2 yarns is stable to hot-moist or mechanical actions during the processing operations.Ovilan-2 yarn which has been dyed in bulk corresponds to the requirements imposed on a raw material for the manufacture of double-weave Jacquard carpeting.Translated from Khimicheskie Volokna, No. 3, pp. 43–45, May–June, 1983.