Optimization of electromagnetic shielding of three-dimensional orthogonal woven hybrid fabrics in ku band frequency region by response surface methodology

Electromagnetic shielding (EMS) has become the necessity of the present era due to enormous expansion in electronic devices accountable to emit electromagnetic radiation. The principal target of this paper is to originate three-dimensional (3D) orthogonal fabrics with conductive hybrid weft yarn and to determine their electromagnetic shielding. DREF-III core-spun yarn using copper filament in the core and polyphenylene sulfide (PPS) fiber on the sheath and fabric constructed of such yarn has a promising electromagnetic shielding characteristic. Box–Behnken experimental design has been employed to prepare various samples to investigate the electromagnetic shielding efficiency of 3D orthogonal woven structures. The orthogonal fabric samples were tested in an electromagnetic Ku frequency band using free space measurement system (FSMS) to estimate absorbance, reflectance, transmittance, and electromagnetic shielding. The increase in copper core filament diameter and hybrid yarn linear density enhances the EMS of orthogonal fabric. Statistical analysis has been done to bring out the effect and interaction of various yarn and fabric variables on EMS. Metal filament diameter, orientation, sheath fibers percentage, and fabric constructional parameters significantly affected electromagnetic shielding efficiency. The inferences of this study can be applied in other 3D structures like angle interlock, spacer fabrics for curtains, and coverings for civilians and military applications.

Effects of weft count and weft density on the surface roughness of 3/1 (Z) twill woven fabric

Purpose The purpose of this study is to investigate the effects of weft yarn diameter and pick density on the properties of surface roughness (SMD) of 3/1 (Z) twill-woven fabrics in three measurement directions weft (0°), the warp (90°) and the diagonal (45°). Design/methodology/approach Nine 3/1 (Z) twill samples were prepared with two factors and three levels and their roughness values were measured in the weft (0°), warp (90°) and diagonal (45°) directions of 3/1 (Z) twill fabrics using the Kawabata-FB4 instrument. Analysis of variance (ANOVA) is used to determine the effect of weft yarn diameter and pick density on SMD properties and comparisons were done in the weft (0°), the warp (90°) and the diagonal (45°) directions. Findings From experimental analysis, weft yarn diameter and pick density affect SMD of 3/1 (Z) twill-woven fabrics in both diagonal (45°) and weft (0°) directions but slightly affect warp (90°) direction. Maximum SMD values were observed in diagonal (45°) directions and the minimum was in warp (90°) directions of fabrics. Weft yarn diameter and pick density are statistically significant on SMD values of 3/1 (Z) twill-woven fabrics for three directions at a 95% confidence interval. Parameter variation in weft directions of 3/1 (Z) twill-woven fabrics also varies SMD values in three directions measurements Originality/value The findings of this study can be usually used for textile technology, industries and laboratories to create a basic understanding for measuring roughness properties of 3/1 (Z) twill fabric. It is also possible to identify the surface characterizations in different directions of measurement for their usage in some specific areas of end application like consumer goods, home textiles, technical textiles, etc.

Weft Yarn Interlacement Modelling for 3D Profiled Structures

Currently, generation of 3D woven T-joint models with complex weave geometries, using TexGen software, is a manual process. One of the main challenges to automatic generation of these textiles is the order in which the weft yarns interlace within the bifurcation region. This paper will demonstrate a method for predicting the order, based on the pattern draft and the information contained within it such as the direction of weft insertion and the beating action of the loom. The path of the entangling weft yarns and the yarn cross section orientation can then be modelled. Finally, a geometric transformation is applied to simulate the opening of the flanges so that the final model reflects the T-shaped profile.

Analysis of the characteristics of air–yarn coupling movement in the profiled reed groove of an air-jet loom

The movement characteristics of yarn in the profiled reed groove of an air-jet loom can have a great impact on the performance of the fabric. Unstable yarn movement tends to lead to weft defects, as short wefts or weft breaks may occur, which could deteriorate the quality of the final fabric. In this paper, the characteristics of the yarn movement in a profiled reed groove are numerically studied. The arbitrary Lagrangian–Eulerian method is used to solve the two-way airflow–yarn interaction and the yarn is simulated with the ball–socket model. A fluctuation ratio is defined to characterize the unsteadiness of the yarn movement. Our simulation first investigates the effect of the gap ratio of the profiled reed groove (β) on the yarn movement then compares the movements of different yarn kinds. The simulation results indicate that a larger β not only decreases gas leaks (thus saves gas consumption), but also stabilizes the yarn movement. Our simulation results also show that the movement of the yarn of polypropylene is more stable than the other two weft-yarn materials. An experiment is also conducted to validate our numerical results, which shows a favorable agreement between them. Our numerical results of the yarn movement in the profiled reed groove can provide a valuable insight into the optimization of the weft insertion system of the air-jet loom.

Fabrication and Mechanical Performance of Non-Crimp Unidirectional Jute-Yarn Preform-Based Composites

This work developed novel jute-yarn, non-crimp, unidirectional (UD) preforms and their composites, with three different types of warp jute yarns of varying linear densities and twists in the dry UD preforms, in order to present a possible solution to the detrimental effects of higher yarn twists and crimp at the warp–weft yarn interlacements of traditional, woven, preform-based composites on their mechanical properties. In the developed UD preforms, warp jute yarns were placed in parallel by using a wooden picture-frame pin board, with the minimal number of glass weft yarns to avoid crimp at the warp–weft yarns interlacements, which can significantly enhance the load-bearing ability of UD composites compared to traditional, woven, preform composites. It was found that an optimal combination of jute warp yarn linear densities and twists in the UD preforms is important to achieve the best possible mechanical properties of newly developed UD composites, because it encourages a proper polymer-matrix impregnation on jute fibres, leading to excellent fibre–matrix interface bonding. Composites made from the 25 lb/spindle jute warp yarn linear density (UD25) exhibited higher tensile and flexural properties than other UD composites (UD20, UD30). All the UD composites showed a much better performance compared to the traditional woven preform composites (W20), which were obviously related to the higher crimp and yarn interlacements, less load-carrying capacity, and poor fiber–matrix interfaces of W20 composites. UD25 composites exhibited a significant enhancement in tensile modulus by ~232% and strength by ~146%; flexural modulus by 138.5% and strength by 145% compared to W20 composites. This reveals that newly developed, non-crimp, UD preform composites can effectively replace the traditional woven composites in lightweight, load-bearing, complex-shaped composite applications, and hence, this warrants further investigations of the developed composites, especially on long-term and dynamic-loading mechanical characterizations.

Pengaruh Variasi Timing Opening Angle Terhadap Jumlah Weft Stop pada Pertenunan Kain dengan Anyaman Keper 2/1 1 di Mesin Air Jet Loom

In the weaving process, the process of launching the weft yarn is an important thing to consider. One of the obstacles that often occurs in the process of launching feed using a water jet loom machine is the amount of feed stuck (weft stop). The cause of the weft stop is because the process of opening the warp mouth is not clean and the weft thread slides inappropriately or too fast so that the warp mouth is in a small condition. Variations in timing opening angle of 700, 800 and 900 determine the size of the warp mouth opening, the time the weft will slide and the time the weft will arrive. From the three variations of the timing opening angle, the number of weft stops at the timing opening angle of 800 is smaller than the timing opening angle of 700 and 900, which is namely the number of big loops 0.6 times and end loops 0.8 times per hour.

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.

Influence of fabric structure on electrical resistance of graphene-coated textiles

Coating is a technique widely used in the textile industry for different purposes, mainly in coloring and functional finishes. Graphene is usually applied to fabrics using coating techniques to provide such fabrics with properties like thermal or electrical conductivity. All woven fabrics have peaks and valleys in their structure, generated by the warp and weft threads interlacing. When spreading the graphene coating, the paste is placed in the fabric’s interstices, and the connection between conductive particles is only produced when the height of the coating is sufficient to connect the different areas where it is deposited. This article analyzes three types of satin weave with three interlacing coefficients (ICs) (0.4, 0.25, 0.17) and two sets of weft yarns each (20 and 71.43 tex). For a blade gap of 1.5 mm, the electrical resistance of samples with weft yarn count of 20 tex and IC of 0.4 is 534.33 Ω, while for IC = 0.25 electrical resistance is 36.8% higher and for IC = 0.17 this parameter increases 249.3%. For samples with weft yarn count of 71.43, the sample with IC = 0.40 exhibits an electrical resistance of 1053 Ω, for IC = 0.25 this value rises to 33.9% and for IC = 0.17 the electrical resistance value increases a total of 78.9%. This finding can be of interest for coatings where continuity is crucial, and for the application of substances that need to be protected from external factors, for which fabrics with deep interstices can be designed to house said products.

The effects of yarn and fabric structural parameters on surface friction of plain-woven fabrics

Purpose Friction is considered to be one property of cloth that has considerable importance in the fields of both technological and subjective assessment for surface properties of textile fabrics. The purpose of this study is to investigate the affective aspects of yarn and fabric structural parameters on the behavior of surface friction of plain woven fabrics. Design/methodology/approach In this study, nine varieties of half-bleached cotton plain-woven fabrics with three weft yarn count (tex) and three weft thread density (ppc) are produced and will be examined for their frictional characteristics. The surface frictional properties of plain-woven fabrics were measured by using Kawabata (KES-Fb4) testing instrument. The ANOVA analysis is used to determine how yarn (count) and fabric (density) structural parameters does influence the surface friction properties of the fabrics. Also, the interaction effects between the factors (count and density) on the response variable (surface friction) of plain-woven fabrics. Findings The findings of this study revealed that the effects of weft yarn count and pick-density have statistically significant on the frictional behavior of the fabric surface properties at a 95% confidence interval. Thus, weft yarn count has a positive correlation with both coefficient of friction (MIU) and mean deviation of coefficient of friction (MMD) on frictional behavior of the fabric surface properties. On the other hand, pick density has a negative correlation with both MIU and MMD on frictional behavior of the fabric surface properties. The weft count, pick density and their interactions (Count X Density) have multicollinearity in the experiment term because the variance inflation factor values were greater than one. Originality/value The findings of this study can be routinely used across the textile industries and laboratories to provide a fundamental understanding regarding the surface frictional properties of the woven fabric for different end applications concerning the yarn structural parameters and fabric structural parameters. And the relationship of count and density with surface friction of plain woven fabrics.