Textured Yarns Research Articles

Textured viscose rayon filament yarn

In many countries of the world the production of textured yarns from thermoplastic polymers has reached a high level of devlopment. Articles processed from this yarn resemble wool in appearance, have a stable high bulk and good elastic stretch, and their useful life is longer than that of articles processed from natural fibres. Their disadvantages include unsatisfactory hygroscopic and physiological properties and a high level of proneness to static charges.

Twist Distribution in False-Twist Texturing Process

The behavior of twist of filaments passing through the twisting zone, including a heater, has been analysed by an experimental false-twisting apparatus under various texturing conditions. The relationship between the number of twists set in the heater and the crimp rigidity of the textured yarn has also been looked into.Briefly, our experiments were made by feeding two multifilaments (black and white) together into the apparatus and observing their behavior in the twisting zone with the aid of photography.The results are summarized:(1) The number of twists in the twisting zone is influenced, for the most part, by the temperature of the filaments textured, the temperature being estimated from the heater temperature and yarn speed.(2) The behavior of twist is also influenced by various other texturing conditions, e.g., yarn tension, the yarn bending angle around the yarn guide, etc.(3) Generally, the observed maximum number of twists is nearly equal to their calculated number, allowing for twist contraction.(4) The crimp rigidity of the textured yarn shows a clear correlation with the maximum number of twists actually set in the heater, but is hardly influenced by the shape of twist distribution.

The Crimp Frequency of False-twist Textured Yarns

The Crimp Frequency of False-twist Textured Yarns

The Crimp Frequency of False-twist Textured Yarns

The Crimp Frequency of False-twist Textured Yarns

Prediction of Stretch-Woven Fabric Behavior From False-Twist Textured Filament Yarn Properties

This paper is concerned with the significance of stretch-textured yarn properties in relation to the character and properties of filling stretch fabrics constructed from them. The study deals with a series of commercially produced false-twist textured polyester and polyamide multifilament yarns having various filament and yarn denier combinations made under different stretch texture processing conditions. These yarns represent differ ent combinations of stretch and bulk texture and cover the range of shrinkage properties and yarn geometries usually employed in the construction of woven stretch fabrics. Each of the false-twist textured yarns was used to construct filling stretch fabrics containing different combinations of weave type, weave texture, and warp yarn count. All of the test fabrics were commercially finished by conventional means to achieve maximum filling stretch potential and were subsequently tested to evaluate fabric stretch performance characteristics. Data obtained during the performance of this work have led to the conclusion that one can obtain a physically meaningful correlation between yam and fabric properties by considering retraction force in addition to linear yam shrinkage. fabric weave type, and fabric cover factors. Prediction of fabric stretch from the properties of false-twist textured yarns depends upon the ability of the yarn test and evaluation procedures to duplicate the loading and mechanical restraint histories experi enced by the yarn during its conversion into woven and finished fabric. The merits of using loom-state as opposed to off-loom dimensions as a basis for computing fabric shrinkage and, hence, computing fabric stretch, are discussed.

11—AN INVESTIGATION OF THE AIR-JET BULKING PROCESS

Experiments aimed at investigating the mechanism of the air-jet bulking or texturing process led to an interesting observation that the textured yarn emerging from the venturi was rotating in such a way as would temporarily untwist the yarn while it was in the jet. The indication is that false-twisting (or untwisting) occurs owing to the vorticity of the turbulent air in the wake of the yarn feed needle that bifurcates the air-stream. The various yarn-processing conditions separately affect the amount of false twist inserted. There is evidence to show that the direction of the vortex, and hence of the untwisting action, is dependent on whether the angular displacement of the feed needle from its central position is in a clockwise or anti-clockwise direction. A suggested mechanism of the process based on the untwisting and retwisting of the overfed filaments offers an explanation for the characteristic locked-in loop structure of air-bulked yarns.

Effect of Physical Properties of Extra-Long Staple Cotton on Yarn Properties, Structure, and Crepeing-Potential

Investigations of several extra-long staple cottons having different physical character istics showed that these properties have little effect on the production of satisfactory crepeing. Of the agents studied for their ability to produce aqueous swelling in cotton, monochloracetic acid at a low degree of substitution proved to be the most effective. However, an unexpected result was that in cotton the degree of swelling of fibers and yarns seems to bear little relationship to the development of crepe effects. Several methods of producing textured cotton yarns and of weaving and finishing crepe fabrics were evaluated. Although attractive 100% cotton crepe fabries were successfully pro duced, additional work to reduce costs is necessary to make them commercially competitive with rayon crepe.'

ジャージ用合繊加工糸について

ジャージ用合繊加工糸について

SOME MORPHOLOGICAL CHARACTERISTICS OF TEXTURED YARN

In order to clarify the morphological characteristics of textured yarn, the individual crimped single filament was separated from the parent textured yarn, and the crimping amplitude and wave-length distribution along a single filament was measured.The following results were obtained:(1) The amplitude and wave-length distribution of crimped filament are similar to that observable in the parent textured yarn, and this distribution discloses diagrammatically the morphological characteristics of the crimp caused by the texturing process.(2) The distribution of amplitude vector along a crimped single filament is identified with the fiber distribution in a cross section of it's parent yarn, and the function of r, which is the accumlation of each amplitude from the outside to r along a radius, is correlated with the fiber distribution f (r) derived in the previous report1).Thus, the fiber distribution f (r) was verified also experimentally by the analisis on the wave distribution in a crimped single filament.

SOME MORPHOLOGICAL CHARACTERISTICS OF TEXTURED YARNS

Employing the optical measurement method proposed in the previous report1), the fibers distribution in yarn has been observed and the following observations have been made that the relation between the distance from the axis of yarn and an intensity of the penetrated light is clearly shown as the Gaussian Distribution Function with respect to all textured yarn regardless of the textured process……the shape of the crimp of yarn……, and that this relation has been kept during the course of the elongation of the yarn. i.e.wherein γ stands for the distance from the axis of yarn and σ represents the Standard Deviation.Basing upon the value of σ of the above formula, the lateral distribution function ρ(γ) or p(γ) was. calculated. The observation agrees with the value of f(γ) of the Gaussian formula, i.e.Consequently, it is inferred that the fibers in a textured yarn are in a random distribution, and this fact is one of the basic characteristics of the textured yarn.

THE TECHNOLOGY OF THE PRODUCTION OF FALSE-TWIST TEXTURED YARNS

Experimental work in the production of false-twist textured yarns using a versatile apparatus is described. Measurements of tension are made at various stages of the process on two systems using different methods of feeding the yarn. The distribution of twist throughout the set-up is discussed. Some measurements of tension are also made on yarns given a simple thermal treatment only. Yarns have been made at a wide range of tensions, twists, and temperatures and are compared in terms of their visual appearance, breaking load and breaking extension, residual shrinkage, stretch, recovery behaviour, specific volume and change in denier on processing.