Technical Yarns Research Articles

Tensile Properties and Fracture Morphology of Viscose Yarn at High Strain Rates

The tensile behavior of textile yams at high speeds is a problem of great practical interest. Higher speeds induce higher strains and, consequently, a higher probability of yarn breaks. In order to ensure acceptable quality even at the highest spinning or weaving speeds, tensile instruments and testing conditions have to be improved. Therefore, we have developed a new high-speed dynamometer and a new method to subject yams at strain rates similar to those found in current textile operations. We use this high-speed dynamometer to investigate the influence of high strain rates on the tensile properties and fracture morphology of a technical viscose multifilament yarn. Data reveal that rapid straining usually results in higher yarn tensile properties. SEM photos show a characteristic granular fracture morphology, but the yarn surface becomes less granular as the strain rate increases.

Study on thermal treatment of hybrid technical yarns

The present paper reports the impact of thermal treatment on the characteristics of core-sheath type hybrid technical yarns. The core-sheath type hybrid yarns are prepared using DREF-III technology. Polyester and glass multifilaments are used as core components whereas the cotton and polyester staple fibers are the sheath components wrapped around the core filament with different proportions to form a hybrid structure. The thermal treatment is carried out both in dry and in wet state under relaxed condition and the thermal shrinkage, sheath-slipping resistance and tensile and bending properties of hybrid yarns have been studied. Thermal treatment markedly increases the thermal shrinkage and sheath-slipping resistance of hybrid yarns with polyester multifilament in core, but insignificant effect for yarns with glass multifilament in core. Breaking elongation of hybrid yarns with polyester multifilament in core increases with treatment temperature. The hybrid yarns with glass multifilament in core are least affected by thermal treatment.

Characterization of oligomers in poly(ethylene terephthalate) by matrix‐assisted laser desorption/ionization mass spectrometry

Matrix-assisted laser desorption/ionization mass spectrometry was used for the characterization of extracted and synthesized oligo(ethylene terephthalate)s. Generally, cyclic oligomers [GT]n could be found in technical yarns and tiles, whereas our synthesized model oligomers mainly consisted of linear chains H-[GT]n-G. In addition, some other distributions could be identified as H-[GH]n-OH and H-[GGT]1-[GT]n-7/-G linear oligomers and H-[GGT]1-[GT]n-1 cyclic oligomers, where G is an ethylene glycol unit, GG is a diethylene glycol unit, caused by impurities of ethylene glycol, and T is a terephthalic acid unit. NMR and IR investigations were carried out to verify these results.

Chain stretching in a poly(ethylene terephthalate) fibre

Molecular deformation during the mechanical straining of single filaments in a high-tenacity poly(ethylene terephthalate) (PET) technical yarn has been investigated using Raman spectroscopy. A significant shift of over 2.5 cm −1 in the peak position of the 1616 cm −1 phenylene ring stretching Raman band was found during deformation up to fibre fracture, and this has been related to chain stretching of the polymer molecules in the fibres during macroscopic deformation. It is found that the change in the position of the Raman band is more closely related to stress than to strain, and the behaviour has been shown to be similar to that of deformed PET films and of high-performance fibres such as aromatic polyamides (aramids).

The SDM40/90: A concept of the Barmag company for the manufacture of technical yarns

The SDM40/90: A concept of the Barmag company for the manufacture of technical yarns

AC10: A one-process technical yarn twisting machine for tire cord production

AC10: A one-process technical yarn twisting machine for tire cord production

Basic directions of research in the area of preparing carbon fibre materials based on hydrocellulose fibres

-- A wide assortment of CFM based on viscose technical yarn has been developed in the VNIIPV and introduced into industry. -- Basic trends of studies in the area of preparing CFM based on HCF have been defined: improvement in the quality of viscose technical yarn; solution of ecological problems in its manufacture; optimization of technology with the purpose of improving characteristics and reducing costs; the development of CFM with qualitatively new characteristics; and the search for new regions of application.

Effect of drying conditions on the properties of tire-cord yarn

-- The drying conditions of technical yarn on a PN-300-IZ machine, where the yarn has been prepared from spinnerets having 2200 holes, has been investigated.

MFTP-1000-KG18 machine for production of high-strength polycaproamide yarn

The construction and principles of operation of an assembly for combining spinning, stretching, and winding of technical polycaproamide yarns have been described, and its technical characteristics have been given.

Analytical control methods for N-1 thermostabilizer in the manufacture of technical polyamide yarn

The chromatographic behavior of technical N-1 has been studied in “Silufol” plates using various eluents.

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

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.

Raising the quality of technical yarn by improving the state of KV-III-250KA twisting and stretching machines

As a result of improving the technical state of the KV-III-250KA machine, a stabilization in the physicomechanical properties of polycaproamide tire cord yarn has been achieved.

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

A series of machines has been developed for the manufacture of viscose textile yarn, viscose technical yarn, polyacrylonitrile fibre, and so on.

Modifier for viscose technical yarn based on cotton soapstock acids

A new domestic modifier for viscose technical yarn has been synthesized — Amiprin KhS-20, based on distilled fatty acids from cotton soapstock.

Conditionality of fatigue properties of polyester yarn on physical structure parameters of the polymer

An interconnection has been found between the conformational composition of the polyethylene terephthalate structure and fatigue properties in specimens of technical polyester yarn.

?Banavis?R viscose fibrous filler

A technological process has been worked out for preparing a new fibrous filler, “Banavis,” for technical rubber articles from viscose technical yarns having a linear density of 187 tex by treating them with a mixture of L-7 chloroprene latex and SF-282 resorcinol-formaldehyde resin.

Double-strand scheme for spinning technical viscose yarn

A two-strand scheme for spinning technical viscose of 183.5 tex linear density has been developed under experimental production conditions. The yarn obtained by this scheme has a breaking load of 38–40 cN/tex at an elongation of 8–10%.

Determination of the maximum diameter of the winding on increasing the weight of a package with a biconical form

A formula has been proposed for determining the instantaneous value of the yarn winding angle in forming a package of biconical form with precision cross-winding. The fundamental possibility of obtaining a package of weight up to 6 kg on a rewinding machine for technical polyamide yarns using existing type PTsG yarn carriers (59.3×300) has been demonstrated.

Estimating the character of the distribution in mechanical properties of technical complex yarns

The possibility of approximating the results of strength (breaking load) tests by the normal, logarithmically normal, or Weibull distribution has been shown in the case of technical complex yarns from various methods of preparation, having various levels of defectiveness. The best confirmity of the experimental data to the three-parameter Weibull distribution has been noted.

Estimation of the scale effect in mechanical testing of technical yarns

On the basis of the statistical theory of strength, a scale effect equation has been formulated for technical complex yarns, on approximation of strength tests by a logarithmically normal distribution.