Effect of Spinning Triangle and Production Speed of Hollow-Spindle System on the Bouclé Yarn Structure

This study aims to show the impact of both the width of the base of the spinning triangle and the production speeds of hollow-spindle spinning machines on the structure of ultimate multiple-thread-structure bouclé yarns and similar fancy yarns. A hollow-spindle spinning machine was used and bouclé yarns were made of a core thread, an effect thread and a (multifilament) binder. Initially, five bouclé yarns were made by setting the widths of the base of the spinning triangle at five levels, i.e. 4.5 mm, 7.5 mm, 10 mm, 13 mm and 16 mm. A further six bouclé yarns were made to show the changes that occur to the spinning triangle at various production speeds. The resulting fancy bouclé yarns were assessed by measuring the size, number and circularity ratio of bouclé profiles. It was found that at low production speeds, i.e. at start-up, that the spinning triangle was unstable, which adversely affected the structure of the final bouclé yarns. However, at production speeds higher than 17 m/min, the spinning triangle became stable, though such a stable spinning triangle had no impact on the structure of the resulting fancy bouclé yarns. The results of this study may help fancy yarn manufacturers to avoid making defective fancy yarns.

Moisture Vapor Permeability and Thermal Wear Comfort of Ecofriendly Fiber-Embedded Woven Fabrics for High-Performance Clothing

This study examined the moisture vapor permeability and thermal wear comfort of ecofriendly fiber-embedded woven fabrics in terms of the yarn structure and the constituent fiber characteristics according to two measuring methods. The moisture vapor permeability measured using the upright cup (CaCl2) method (JIS L 1099A-1) was primarily dependent on the hygroscopicity of the ecofriendly constituent fibers in the yarns and partly influenced by the pore size in the fabric because of the yarn structure. On the other hand, the moisture vapor resistance measured using the sweating guarded hot plate method (ISO 11092) was governed mainly by the fabric pore size and partly by the hygroscopicity of the constituent ecofriendly fibers. The difference between the two measuring methods was attributed to the different mechanisms in the measuring method. The thermal conductivity as a measure of the thermal wear comfort of the composite yarn fabrics was governed primarily by the pore size in the fabric and partly by the thermal characteristics of the constituent fibers in the yarns. Lastly, considering market applications, the Coolmax®/Tencel sheath/core fabric appears useful for winter warm feeling clothing because of its the good breathability with low thermal conductivity. The bamboo and Coolmax®/bamboo fabrics are suitable for summer clothing with a cool feel because of their high thermal conductivity with good breathability. Overall, ecofriendly fibers (bamboo and Tencel) are of practical use for marketing environmentallyfriendly high-performance clothing.

Effect of Different Yarn Combinations on Auxetic Properties of Plied Yarns

This study presents the effects of a novel plied yarn structure consisting of different yarn components and yarn twist levels on the Poisson's ratio and auxetic behavior of yarns. The plied yarn structures are formed with bulky and soft yarn components (helical plied yarn [HPY], braided yarn, and monofilament latex yarn) and stiff yarn components (such as high tenacity [HT] and polyvinyl chloride [PVC]-coated polyester yarns) to achieve auxetic behavior. Experimental results showed that as the level of yarn twist increased, the Poisson's ratios and the tensile modulus values of the plied yarns decreased, but the elongation values increased. A negative Poisson's ratio (NPR) was obtained in HT–latex and PVC–latex plied yarns with a low twist level. The plied yarns formed with braid–HPY and braid–braid components gave partial NPR under tension. A similar result was achieved for yarns with HT–latex and PVC–latex components. Since partial NPR was seen in novel plied yarns with braided and HPY components, it is concluded that yarns formed with bulky–bulky yarn components could give an auxetic performance under tension.

A STUDY ON ENHANCING THE FLAME RETARDANCY OF POLYPROPYLENE YARN WITH BORON COMPOUNDS

Functional properties such as; water resistance, flame retardancy, antibacterial efficiency etc. are required from textile products. One of the most commonly demanded products among functional textile products is the flame-retardant textiles. In this study, it is aimed to produce polypropylene filament yarn with permanent flame retardancy functionality by adding boron compound, which is Anhydrous disodium tetraborate powder (particle size < 38 micron), to the fiber structure during melt spinning process. In this study two different yarn samples are produced with anhydrous disodium tetraborate content by mass ratios of 2% and 5%. A control polypropylene filament yarn sample is also produced with no additive. By this way, three samples are produced by a conventional BCF polypropylene melt spinning machine with the same production parameters. Then, three knitted fabric samples were produced flat knitting machine. Limiting Oxygen Index (LOI) and vertical flammability tests were applied to the samples. According to results an important level of increase for LOI value is obtained with the sample which has 2% boron compound additive. Nevertheless, there is not a consistent effect of increasing boron content in yarn structure for LOI value. The reason of this situation may be resulted due to the uneven distribution of the boron compound in the yarn structure because of the particle size.

Parametric study on mechanical properties of basalt leno textile applied as concrete reinforcement

In this study, the mechanical properties of the basalt leno textile applied as concrete reinforcement were experimentally investigated considering different parameters including the impregnation materials, geometrical characteristics (the number of yarns, yarn structure, and yarn spacing), and loading rate. The tensile strength, elastic modulus, and failure mode were examined. Furthermore, the force mechanism of impregnated leno textile under tensile load was analyzed. The experimental results showed that the textile with a stiff impregnation material exhibited a higher strength and modulus than that with a flexible material. The leno textile with the straight yarn had a better performance than those with the twisted yarns. Besides, the constraint of the weft yarns is obvious to the textile in the warp direction, while the warp yarn makes no contributions to the bearing capacity of textile in the weft direction. The weft yarn spacing had a significant impact on mechanical properties of the textile in the warp direction. Furthermore, the loading rate of approximately 1.2 mm/min was suggested to determine the maximum force of the impregnated basalt leno textile. A tensile strength model was proposed considering the effects of the impregnation material, consistent deformation, torsion damage, and twisted angle.

Engineering the Structure of Multi-thread Fancy Bouclé Yarn: Individual Effects of the Number of Wraps and the Overfeed Ratio

This study is about the influence of the number of wraps and the overfeed ratio on the fancy bouclé yarn structure. The bouclé yarns of this study were made on a hollow-spindle spinning system. The number of wraps and the overfeed ratio were increased incrementally and individually in two different experiments. It was found that there were significant linear relationships between increasing the overfeed ratio and increasing the number and size of fancy bouclé profiles, but at the expense of decreasing their circularity ratio and changing the bouclé yarn morphology. However, increasing the number of wraps made a significant linear reduction to the size of fancy bouclé profile but without affecting their number. This study aids bouclé yarn manufacturers to increase their understanding of the structure and aesthetics of bouclé yarns. It also shows them how the morphology of bouclé profiles may change when the overfeed ratio or the number of wraps is changed. In particular, variants of bouclé profiles may appear, which can increase the potential for those variants to attract the attention of designers and consumers. It also can strengthen the manufacturers’ capabilities to satisfy the needs of a wide range of consumers, by creating a wider range of novelty clothing.

Investigation of Twist Waves Distribution along Structurally Nonuniform Yarn

This paper presents the features of yarn structure formation on spinning machine, i.e. yarn twist change when winding. It was considered that the twist distribution was one of the reasons for its decrease along the formed yarn. In this paper, based on analysis of changes in thickness and twist due to axial deformation, we consider a yarn moving at constant speed. Moving dynamics of yarn are studied here by using Euler variables. The correspondences of forward and reverse twist waves’ distribution speeds on presented frequency at various vibration forms are obtained. The parameters of Doppler effect for the waves distributed along the yarn are determined.