A Calculation Method for the Deformation Behavior of Warp-Knitted Fabric

In this paper, a new method to simulate the structure and loop deformation behavior of double-bar reflex-lapping warp-knitted fabrics based on the structural characteristics is proposed. A simplified mass-spring model was built in which loops knitted by filaments were considered as particles with the uniform mass distribution connected by structure springs for overlaps and shear springs for underlaps. Deformation forces and direction on particles were analyzed to describe the displacement and deformation behavior of particles. A loop model with eight control points was established, and the relationship between control points and particles was studied combining the quadratic Bezier curves. The deformation simulation was implemented by a simulator program with C# and JavaScript via web technology on Visual Studio 2015. The stereoscopic sense of filaments was realized by changing the direction and intensity of the light. The results show that the fabric deformation and the loop shape can be accurately achieve using the simplified mass-spring model compared with the real sample.

The Influence of the Structure Parameters on the Extensibility of Woven Fabrics

Fabric deformation properties considerably depend on its structure. Garment elasticity is an important factor that allows a garment wearer to move freely. Fabric deformation depends on the structure parameters of yarrn and fabric. It has been known that elongation at break of fabric with elastane yarn is higher than of ordinary fabric. The aim of this work was to analyse elongation at break parameters of the and warp and weft yarn in fabrics. Ten commercially produced samples of woven fabrics were used in the experiment. Some samples were with elastan yarn in the warp and weft directions or only in the weft direction. Elongation at break was measured applying a standard method. The results showed that elongation at break of the main elastic component or another component may occur simultaneously when an elastic component or elastane yarn may reach fabric ultimate elongation.

Influence of Tensile Stress on Woven Compression Bandage Structure and Porosity

Woven compression bandage (CB) is one of the elastic textiles that exert pressure on muscles. With a defined tensile strength, it is possible to create the required compression on the given body parts. This work aims to investigate the relationship between woven fabric deformation, porosity, and tensile stress properties of three main types of woven CBs. All bandage samples are applied on human leg using two- and three-layer bandaging techniques. Bandage porosity is calculated for all frames at different weave angles using NIS software. Woven bandage construction parameters which are given by the preparation of warp and weft yarns, twist, count, and density along with woven fabric weave, type of weaving, and finishing process are the main factors that influence the bandage properties. Several methods considering thread distributions have been developed to determine the woven fabric's porosity during the tensile stress. Experimental results confirm that bandage porosity is directly proportional to the bandage extension and weave angle that ranges from 44° to 90°. The novelty of candidate study is to introduce practical remarks to the patient for optimizing the required bandage pressure by suitable extension or applied tension or weave angle for two- and three-layer bandaging systems.

The Effect of Single and Dual-Core Yarns Produced with Different Core Materials on the Elasticity and Recovery Properties of Denim Fabrics

Elastic structures are preferred for improving the elasticity and recovery of the fabrics. Bagging, which is a three-dimensional fabric deformation, is an undesirable appearance of fabrics. The lack of dimensional stability or recovery after pressure on the fabrics causes bagging deformation. In recent years, denim manufacturers prefer double-core yarns to cope with the problem of bagging. In this study, various types of weft yarns were produced by using different core materials in different combinations. Double-core and single-core ring-spun yarns (Ne 18, ae 4,4) were used as weft yarns in weaving. Yarn and fabric samples were conditioned under standard atmospheric conditions and measured according to the related test standards. Yarns were tested and evaluated for important physical and mechanical properties such as evenness, imperfections, tenacity, breaking elongation, hairiness and yarn liveness. For denim fabric samples, all tests were performed after 3 consecutive domestic washing processes. Test results showed that there are significant differences between fabric properties depending on the weft yarn characteristics. By using double-core weft yarns in denim fabric production, consumers can have stretch jeans for improving body movement comfort while exhibiting low growth and shrinkage values.

Progress on the Fabrication of Smart Textiles Based on Soft Strain Sensors

The focus of this study is on strain sensing research and applications in smart textiles. Strain sensing is the measurement of fabric deformation by embedding a strain-sensitive material in it and subjecting it to stress. This paper presents an extensive classification of knitted textile strain sensors. Salient knitted strain sensor production parameters, such as conductive yarn choice, fabric structure, fabric structure deformation, and its relationship to strain signal extraction are discussed. The study concludes that producing yarn-based soft strain sensors for smart textile applications is viable. However, sensitive yarns with the right conductivity, count, and structural configuration are often unavailable. Work remains in the areas of efficient fabric deformation, signal extraction methods, development of sensor nodes, and robust experimental testing systems.

Flexible Textile Strain Sensor Based on Copper-Coated Lyocell Type Cellulose Fabric

Integration of sensors in textile garments requires the development of flexible conductive structures. In this work, cellulose-based woven lyocell fabrics were coated with copper during an electroless step, produced at 0.0284 M copper sulfate pentahydrate, 0.079 M potassium hydrogen L-tartrate, and 0.94 M formaldehyde concentrations. High concentrations led to high homogeneous copper reaction rates and the heterogeneous copper deposition process was diffusion controlled. Thus, the rate of copper deposition did not increase on the cellulose surface. Conductivity of copper coatings was investigated by the resistance with a four probe technique during fabric deformation. In cyclic tensile tests, the resistance of coated fabric (19 × 1.5 cm2) decreased from 13.2–3.7 Ω at 2.2% elongation. In flex tests, the resistance increased from 5.2–6.6 Ω after 5000 bending cycles. After repeated wetting and drying cycles, the resistance increased by 2.6 × 105. The resistance raised from 11–23 Ω/square with increasing relative humidity from 20–80%, which is likely due to hygroscopic expansion of fibers. This work improves the understanding of conductive copper coating on textiles and shows their applicability in flexible strain sensors.