Search results

The purpose of this paper is to investigate warp and weft crimp distribution over the fabric width and how it is influenced by warp tension distribution over the warp width.

An experimental design in this research includes air jet loom, tension sensor, inductive sensor and personal computer.

It is found that warp crimp in the fabric on the loom is higher in the edge zones than the middle of the fabric and warp crimp in the middle is higher than warp crimp in edge zones of the grey fabric. Weft crimp in the edge zones is higher than in the middle of the grey fabric. The reason behind warp tension and warp and weft crimp variations over fabric width is that weft yarn slips towards inside fabric at selvedges and gets relaxed during beat up.

It is proved that reducing weft yarn slip and therefore weft yarn relaxation during beat up will reduce warp tension and warp and weft crimp variations and improve the uniformity of fabric properties over the fabric width.

Bending and shear rigidities of woven fabrics depend on fibre, yarn and fabric-related parameters. However, there is lack of research efforts to understand how bending and shear rigidities change in woven fabrics having similar areal density. The purpose of this paper is to investigate the change in bending and shear rigidities in plain woven fabrics having similar areal density.

A total of 18 fabrics were woven (9 each for 100 per cent cotton and 100 per cent polyester) keeping the areal density same. Yarns of 20, 30 and 40 Ne were used in warp and weft wise directions and fabric sett was adjusted to attain the desired areal density.

When warp yarns become finer, keeping weft yarns same, bending rigidity remains unchanged but shear rigidity increases in warp wise direction. When weft yarns are made finer, keeping the warp yarns same, both the bending and shear rigidities of fabric increase in warp wise direction. Similar results for fabric bending and shear rigidities were obtained in transpose direction. There is a strong association between fabric shear rigidity and number of interlacement points per unit area of fabric even when fabric areal density is same.

Very limited research has been reported on the low-stress mechanical properties of woven fabrics having similar areal density. A novel attempt has been made in this research work to investigate the bending and shear rigidities of woven fabrics having similar areal density. Besides, it has been shown that it is possible to design a set of woven fabrics having similar bending rigidity but different shear rigidity.

Tensile property is one basic mechanics performance of the fabric. In general, not only the tensile values of the fabric are needed, but also the dynamic changing process under the tension is also needed. However, the dynamic tensile process cannot be included in the common testing methods by using the instruments after fabric weaving.

By choosing the weft yarn and warp yarn in the fabric as the minimum modeling unit, 1:1 finite element model of the whole woven fabrics was built by using AutoCAD software according to the measured geometric parameters of the fabrics and mechanical parameters of yarns. Then, the fabric dynamic tensile process was simulated by using the ANSYS software. The stress–strain curve along the warp direction and shrinkage rate curve along the weft direction of the fabrics were simulated. Meanwhile, simulation results were verified by comparing to the testing results.

It is shown that there are four stages during the fabric tensile fracture process along the warp direction under the tension. The first stage is fabric elastic deformation. The second stage is fabric yield deformation, and the change rate of stress begins to slow down. The third stage is fiber breaking, and the change of stress fluctuates since the breaking time of the fibers is different. The fourth stage is fabric breaking.

In this paper, the dynamic tensile process of blended woven fabrics was studied by using finite element method. Although there are differences between the simulation results and experimental testing results, the overall tendency of simulation results is the same as the experimental testing results.

The tension variations across the width of the weaver's beam cause uneven tension in the fabric formation zone. As a result of the tension variation, the woven fabric tends to have fabric defects, such as non-uniform fabric density and differential dye take–up at various places on the fabric. As the warp ends are continuously subjected to varying tensions, warp breakage frequently occurs. As a result, the quality of the fabric produced suffers and there is reduced loom efficiency. However, uniformity in the fabric density is crucial, especially for technical and smart textiles. In this paper, the authors have attempted to model the varyingtensions across different segments of a warp sheet under a set of assumptions and derived a linear model. Furthermore, a prototype of an automatic tension control device is instrumentedwith two different positions which are located one meter apart and allows the tension variations across the warp-sheet to be practically observed. The measured average tension shows that variations in the internal tension on different segments of the warp-sheet can be minimized or even completely eliminated over time. With the implementation of a related experiment, the authors have shown the effectiveness of this automatic tension controller and its strong implications for the industry.

The purpose of this paper is to theoretically compute and predict the needle penetration force (NPF) in woven denim fabrics with twill 3/1 weave pattern on the basis of geometrical, physical, and mechanical properties of yarns and fabric, and characteristics of sewing needle.

To predict the NPF by mathematical relations, the proposed models by Stylios and Xu (1995) and Lomov (1998) are extended for a twill woven structure. The NPF is calculated based on resistance forces due to yarn tensile elongation, yarn resistance to bending in the near of the sewing needle while the needle penetrates into the fabric, friction between weft and warp yarns, needle profile shape, and friction between sewing needle and yarns. In order to evaluate the obtained results, nine different denim fabric samples are produced, and five sewing needles with different sizes are used. The NPF is measured on the Instron tensile tester to simulate sewing process.

The results show that there is a good relationship between the predicted and experimental values of the NPF (R2=0.831, MSE=0.079, and MAPE=9.51 percent). Moreover, it is found that the performance of developed model to predict the NPF for needle sizes of 80, 90, 100, and 110 (Nm) is better than that of needle size of 120 (Nm). Generally, the developed theoretical model can predict the NPF in fabrics with twill 3/1 weave pattern.

The fabrics with twill weave pattern have a complicated structure than plain pattern. So, in this research work, the NPF of denim fabric with twill 3/1 weave pattern was theoretically predicted on the basis of yarn elongation, changing of yarn bent shape in the near of the sewing needle, and friction between warp and weft yarns. The NPF was measured in the successive cycle loading conditions similar to sewing machine process by using a designed and constructed instrument, which is mounted on the Instron tensile tester.

Presents general properties and examples of weaves for two‐component multilayered woven fabrics. Such fabrics have a combination of properties which it is difficult to achieve in traditional fabrics (bulk combined with good tenacity, high cover level with porosity), can be used in liningless garments and can cope with ergonomical restrictions when using fibres with special protective properties. Describes a CAD system which can be used as an aid for a technologist to choose yarns for warp and weft, fabric weave and picks/ends count to meet demands specified by a particular fabric usage. It employs a new method of coding of multilayered fabric structure; mathematical methods used are based on the mechanical model of yarns interaction in a fabric. This describes the spatial disposition of yarns which allows production of any desired images of fabric geometry, i.e. surface smoothness or shape of pores. Discusses the complex nature of porosity of multilayered fabrics.

The purpose of this research is to design 3D print and analyze mechanical as well as microstructural behavior of interlaced fibrous structures using Dremel 3D45 additive manufacturing (AM) machine.

A series of plain and twill weave fabrics are designed using computer-aided design software Solidworks and printed using fused deposition modeling machines to determine the best model that could be printable. The structures were designed in such a way that the fabricated yarns with pure (PLA) were not sticking to each other in the fabric structure. The specimens were printed in vertical orientation and then tensile and three-point bending (flexural) tests were conducted for twill weave fabrics.

The tests showed that the mechanical strength was higher in the warp direction than in the weft direction. This difference was because of printing of continuous filament-like yarns in the warp direction and staple-like yarns in the weft direction. This orthotropic property of the material was verified by analyzing its microscopic structures via optical microscope.

Future work should include improvement of the structure and exploration of different polymers and their composites to increase the tensile, bending and other strengths to make the 3D-printed structures more flexible and stronger. Future research should also focus on the large-scale manufacturing of 3D printed fabrics.

This paper supports work on wearable 3D-printed fabrics. The 3D-printed fabric will also contribute to new applications and products such as liquid filters.

The research done in this work is new and original. This paper contributes to new knowledge by providing a better understanding of polymers and their 3D printing capabilities to form a complex fabric structure.

The aim of this study was to understand the stick-slip properties of single and multiple yarn pull-out in dry and treated polyester satin woven fabric in boundary regions.

Polyester satin pattern woven fabric was used to conduct the pull-out tests in order to examining the kinetic region of the force-displacement curve. Data generated from this research help the authors to obtain stick-slip force and accumulative retraction force.

It was found that stick-slip force and accumulative retraction force depend on the number of pulled ends in the fabric, fabric sample dimensions and softening treatments. Stick-slip forces of polyester satin fabric in the multiple yarn pull-out test were higher than those of the single yarn pull-out test. Stick-slip force in single and multiple yarn pull-out tests in the dry polyester satin fabric was generally higher than those of the softening treated polyester satin fabric. In addition, the warp directional single and multiple yarn stick-slip and accumulative retraction forces in the dry and softening treated polyester fabrics were generally higher than those in the weft direction in the fabric edges due to fabric density. On the other hand, the amount of stick-slip force was related to the number of interlacement points in the fabric, whereas the amount of accumulative retraction force was related to fabric structural response.

The mechanism of stick-slip and accumulative retraction force of dry-treated polyester satin pattern woven fabrics were explained. This research could be valuable for development of multifunctional fabrics in technical textiles and ballistic.

This paper seeks to report an experimental investigation on the tearing and tensile strength behaviour of military khaki fabrics from grey to finished process.

Uses three different types of military fabric (3 up 1 down twill), differing in type of constituent yarns (ring/rotor) in order to test their tearing and testing strength behaviour.

Tearing strength of fabric is found to be very much susceptible to change due to the process variation, while fabric tensile strength is relatively less sensitive. Ring spun yarn fabric shows higher tearing strength compared with rotor spun yarn fabric. However, the difference in their tearing strength reduces substantially as the process approaches towards the finished state. On the other hand, rotor spun yarn fabric exhibits higher tensile strength along the warp. Tearing strength along bias direction is in between warp and weft wise tearing strength; whereas tensile strength is lowest while tested along the bias direction. During the grey to finished process, tear strength falls at bleaching and dyeing, and particularly drops in strength is being more at the dyeing stage.

This study has investigated the tearing and tensile strength behaviour of military khaki fabrics from grey to finished state, developing understanding of the impact of different processes on the tearing strength, so that fabric of the required tear strength can be developed with process modification.

In recent times, stretch denim garments have become very popular amongst consumers as the garment is able to provide body fit and body comfort at the same time. The purpose of this study is to investigate the effect of abrasion on the change in surface appearance, mass loss and ultimate tensile properties of the stretch denim fabric in different directions (warp, weft and biased).

After abrading the fabrics in three different directions (warp, weft and biased), the loss in ultimate tensile properties, mass loss and surface appearance has been investigated in the respective directions of abrasion (warp, weft and biased). The study also encompasses the effect of different types of stretch yarn with varying levels of elastane content on such unidirectional abrasive damage.

It is seen that with the same level of abrasion cycles, the fabric's response in terms of mass loss and loss in ultimate tensile properties are different in different directions. The mass loss due to abrasion in biased direction is found to be minimum. The loss in ultimate tensile properties due to abrasion was highest in the weft direction. It is also found that the higher mass loss due to abrasion does not always result in a greater loss in ultimate tensile properties. The composition and the structure of the weft yarn significantly affected the extent of the mass loss and the loss in ultimate tensile properties during abrasive damage.

The impact of abrasive damage in terms of mass loss and loss in tensile strength along the different directions of denim fabric has not been explored till date. Abrasion of fabric can be done both in multi-direction (Lissajous motion) as well as in uni-direction (linear motion). The multidirectional abrasion provides a holistic or comprehensive idea of the fabric's response to the abrasive damage but does not take into consideration the fabric's anisotropic response to the abrasive damage. Most of the earlier investigation related to abrasive damage of denim fabric has been done in instruments where the motion of the abrader is multidirectional (Lissajous) in nature. For greater depth of understanding about the fabric performance under abrasive damage along the various direction (warp, weft and biased), unidirectional abrasion is conducted in this study.