Determination of fabric physical properties for the simulation of Cusick drapemeter

A fabric drape shape database has been prepared to find the optimum combination of fabric physical properties for simulating the appearance of an actual fabric. First, an objective and quantitative evaluation method for the traditional Cusick drape tester has been devised. Then a virtual drape tester has been developed using an implicit integration based drape simulation engine to generate a series of virtually draped fabric with various physical properties. Finally, a search algorithm has been developed to find the optimum property combination for target fabric by comparing the simulated results with the Cusick drape tester result of that fabric.     

Fast garment drape simulation using geometrically constrained particle system

A simulation system for versatile garment drape has been developed. Using this system, the shape of a garment can be simulated in consideration of fabric physical properties as well as the interaction between fabrics and other objects. Each fabric piece in a garment is modeled using a geometrically constrained particle system and its behavior is calculated from an implicit numerical integration algorithm in a relatively short time. The system consists of three modules including a preprocessor for the preparation of fabric patterns and external objects, a postprocessor for the results of three-dimensional visualization, and a drape simulation engine. It can be used for the design process of textile goods, garments, furniture, or upholsteries.     

Estimation on the 3D porosity of plain knitted fabric under uniaxial extension

In this article we study the 3D porosity of plain weft knitted fabric while is subjected to extension under different uniaxial extension in course direction. There are a few models for 3D porosity investigation of weft knitted fabrics such as Benltoufa model and Karaguzel model as theoretical models and empirical Guidoin model. To investigate the accuracy of these models, plain knitted fabrics were produced over a different range of knitting stiffness. Thereafter, the estimated porosities of the fabrics using the theoretical models were compared with the experimental values which are obtained from Guidoin empirical model. It was concluded that Karaguzel model shows reliable and trustful result while, Benltoufa model shows huge differences in comparison with Guidoin model. In order to reduce these differences, an improved model which is named as i-model is introduced.     

Effect of heat setting parameters on some properties of PLA knitted fabric

This article reports the outcome of a study conducted for examining the effect of heat setting parameters on some properties of PLA knitted fabric. Three heat setting parameters, namely, treatment time, treatment temperature, and tension, were considered for optimizing the heat setting process with fabric shrinkage after dyeing and color yield as the evaluation factors. Experimental results revealed that lower shrinkage and higher color yield can be achieved when: (i) heat setting time = 60 s; heat setting temperature=130 oC; and tension=0%. After that, the PLA knitted fabric was treated under the optimum heat setting condition and was dyed with 1% depth disperse dye, which produced a better dyeing result. However, the handle of the heat set PLA knitted fabric, as measured by Kawabata Evaluation System for Fabric (KES-F), became stiffer and more resistant to shearing movement and had worse drape and bending recovery ability, while the appearance became fluffier and rougher.     

Investigating seamed woven fabric drape using experimental and virtual approaches

The aim of this study was to investigate the drape properties of seamed woven fabric using experimental and virtual approaches. Firstly, the influence of different seams on the fabric drape parameters was analyzed based on bending and draping experiments. Then, a preliminary drape simulation method for seamed fabric was presented using shell finite elements. The models with seams were simplified and separated into shell fabric partitions and seam partitions. The projection images of all models were extracted for calculating the drape coefficient and average radius. Through contrasting of drape profiles and correlate analysis of drape parameters, it shows that the drape properties between simulating and testing are very similar and correlated. Furthermore, their regression formulas of drape coefficient and average radius were given by regression analysis. The work has some helps for further study on evaluating and simulating the garment aesthetic performance in considering of seam’s mechanical properties.     

Investigation of air permeability of core spun cotton/spandex weft knitted structures under relaxation

In this research work, air permeability variations of core spun cotton/spandex single jersey and 1×1 rib knitted structures were studied under relaxation treatments. Results are compared with similar fabrics made from 100 % cotton material. Even though cotton/spandex fabrics knitted with same stitch lengths, their structural spacing and stitch densities vary with the progression of treatments. Similar behavior was also observed with 100 % cotton knitted structures. Under higher machine set stitch lengths (i.e., lower fabric tightness factor), higher structural spacing and lower stitch densities were resulted and those variations significantly affected on the air permeability variations of knitted structures. 1×1 rib knitted structures showed significantly higher air permeability than single jersey structures and it is more prominent with cotton rib structures. However, cotton/spandex 1×1 rib and single jersey structures have not showed such significant deviations. Air permeability of cotton/spandex and 100 % cotton rib and single jersey knitted structures decreased with lower machine set stitch lengths (i.e., at higher fabric tightness factors). There was a correlation with fabric tightness, air permeability, areal density and fabric thickness such as knitted fabrics became tighter, their weight and thickness were higher, while their air permeability was lower. Thus, fabric areal density and fabric thickness are positively correlates to machine set stitch length^?1 (fabric tightness factor). Air permeability of a knitted structure depends on material type, knitted structure, stitch length, relaxation treatment, structural spacing and stitch density.     

Evolution of moisture management behavior of high-wicking 3D warp knitted spacer fabrics

Moisture management behavior is a vital factor in evaluating thermal and physiological comfort of functional textiles. This research work studies functional 3 dimensional (3D) warp knitted spacer fabrics containing high-wicking materials characterized by their profiled cross section. These spacer fabrics can be used for protective vest to absorb a user’s sweat, to reduce the humidity and improve user’s thermal comfort. For this reason, different 3D warp knitted spacer fabrics were produced with functional fiber yarns in the back layer of the fabric (close to the body) and polyester in the front and middle layers (outer surface). Comfort properties such as air and water vapor permeability and wicking and other moisture management properties (MMP) of different fabric samples were measured. It is demonstrated that by using profiled fibers such as Coolmax fiber, moisture management properties of spacer fabrics can be improved, enabling them to be use as a snug-fitting shirt worn under protective vests with improved comfort.     

Flexural stiffness of core spun cotton/spandex weft knitted structures under relaxation and machine washing treatments

In this research work, behavior of flexural stiffness of core spun cotton spandex single jersey, 1x1 rib and interlock fabrics was studied under relaxation and machine washing treatments. Results are compared with similar fabrics made from 100 % cotton. Fabric weight density increased with the progression of treatments and it is proportionate to the fabric tightness factor (stitch length^?1). Even though both types of fabrics had same machine set stitch lengths, cotton/spandex fabrics have shown the higher fabric weight densities than that of 100 % cotton fabrics. Although 1x1 rib and single jersey fabrics knitted with the same machine set stitch lengths, rib fabrics have given higher fabric weight densities than single jersey fabrics. Among the three knitted structures, interlock fabrics with higher machine set stitch lengths gave the higher fabric weights. Fabric stiffness and flexural rigidity have given higher values under the progression of treatments and it was found that higher values of stiffness have given by cotton/spandex knitted fabrics compared to their cotton fabrics. Fabric stiffness and flexural rigidity in wale direction were higher than that in course direction, but it is only observed in single jersey fabrics. However, 1x1 rib and interlock fabrics have shown an opposite behavior. It was also observed a positive correlation between TF (i.e.: stitch length^?1) and bending length/flexural rigidity in both fabric types. Lower flexural rigidities reported with single jersey structures and highest values gave with interlock structures of cotton/spandex and cotton fabrics.     

A comparative study of cotton knitted fabrics and garments produced by the modified low twist and conventional ring yarns

Spirality is one of the major potential problems in knitted fabrics and garments. It affects the aesthetics and physical properties of the garment produced, such as the seam displacement, shape retention, pattern distortion and sewing difficulties. In this paper, a comparative study has been carried out to evaluate the physical performance of 100 % cotton knitted fabrics and garments produced by the modified low twist and conventional ring yarns through the actual wearing and washing trials. Experimental results showed that the properties of side seam displacement, fabric spirality, dimensional stability and skewness change of the T-shirts and sweaters made by the modified single yarns are comparable to those of garments made from the control plied yarns but much improved when compared to those from the control single yarns. In addition, the pilling resistance and bursting strength of the knitted fabrics made by the modified single yarns can still maintain a reasonably high level at a low yarn twist.     

Shadow Moiré aided 3-D reconstruction of fabric drape

The existing standard test method assesses draped fabrics two-dimensionally. In this study, a novel method is introduced to analyze and quantify fabric drapes in 3-D by using shadow moiré method. Six different woven fabrics with dissimilar drape behaviors have been analyzed. A drape index has been mathematically derived from the moiré patterns employing the shadow moiré topography technique. The results have been compared with the standard drape coefficient. The 3-D profile of fabrics has been graphically formed and displayed applying the moiré fringes?? data.     

Effect of filament size on the water transport of weft and warp knitted fabrics

Warp and weft knitted fabrics comprising polyethylene terephthalate/Co-PET sea-island bicomponent fibers were fabricated in this study. The knitted fabrics were treated in alkali solution to develop knitted fabrics composed of nano-scale filaments. The structural change and water transport behavior of the alkali-treated knitted fabrics were then compared. Results revealed that the filament diameters decreased from 20 µm to 850 nm after alkali treatment. The porosities of warp and weft knitted fabrics decreased by 4.8 % and 10.1 %, respectively, whereas their area densities increased by 68.8 % and 67.2 %, respectively. The wicking height and wicking rate of both types of fabric composed of microfilaments increased with prolonged alkali-treatment time. However, the water absorption properties such as absorption capacity and absorption rate of the knitted fabrics composed of nano-scale filaments significantly increased because of their low porosity and high area density.     

Investigation and modeling of air permeability of Cotton/Polyester blended double layer interlock knitted fabrics

The aim of this study was to analyze and model the effect of knitting parameters on the air permeability of Cotton/Polyester double layer interlock knitted fabrics. Fabric samples of areal densities ranging from 315–488 g/m² were knitted using yarns of three different cotton/polyester blends, each of two different linear densities by systematically varying knitting loop lengths for achieving different cover factors. It was found that by changing the polyester content in the inner and outer fabric layer from 52 to 65 % in the double layer knitted fabric did not have statistically significant effect on the fabric air permeability. Air permeability sharply increased with increase in knitting loop length owing to decrease in fabric areal density. Decrease in yarn linear density (tex) resulted in increase in air permeability due to decrease in areal density as well as the fabric thickness. It was concluded that response surface regression modeling could adequately model the effect of knitting parameters on the double layer knitted fabric air permeability. The model was validated by unseen data set and it was found that the actual and predicted values were in good agreement with each other with less than 10 % absolute error. Sensitivity analysis was also performed to find out the relative contribution of each input parameter on the air permeability of the double layer interlock knitted fabrics.     

Drape simulation of three-dimensional virtual garment enabling fabric properties

This study analyzes how the silhouette of virtual garments applied to virtual avatars is altered according to various virtual fabric properties. This study measures the properties of real fabrics that include a charmeuse (#F1) and gabardine (#F2) using the Fabric Analysis by Simple Testing system; in addition, the material properties of different real fabrics were applied to that of the virtual fabric. It then evaluates the drape stiffness and silhouette of the virtual garments according to the different fabrics. This study also compared the virtual garment silhouette of sample fabric #F1-S that changed only the stretch property of the sample fabric #F1 with the virtual garment silhouette of sample fabric #F1. The results show that the fabric properties including bend, thickness, weight, stretch, shear values affect the drape stiffness, silhouette, and fit of the virtual garment simulated on virtual avatars and may be used for the realistic virtual garment technology.     

Dimensional and physical properties of plain knitted fabrics made from 50/50 bamboo/cotton blended yarns

In this study, the dimensional and some physical properties of plain knitted fabrics made from 50/50 bamboo/cotton blended yarns are investigated. In order to see the differences and similarities, the results are then compared with those for similar fabrics knitted from 50/50 conventional viscose/cotton and 50/50 modal/cotton blended yarns. Each fabric type was produced with three different stitch lengths. After all fabrics were dyed under identical dyeing conditions, they were subjected to dry and full relaxation treatments. For dimensional properties of fabrics, course, wale and stitch densities were measured. Then, by calculating statistically best-fit lines passing both through the experimental points and the origin, dimensional constants i.e. k values were predicted in terms of the fiber types. The result show that each fabric type knitted from bamboo/cotton, viscose/cotton and modal/cotton blended yarns behaves in a similar manner. However, in both dry and fully relaxed states, the modal/cotton knitted fabrics tend to have slightly higher k values than the bamboo/cotton and viscose/cotton knitted fabrics. For physical properties, fabric weight per unit area, thickness, bursting strength, air permeability and pilling were evaluated. The results show that the weight, thickness and air permeability values are independent of the fiber type. Plain knitted fabrics from modal/cotton blended yarns have the highest bursting strength values. Plain knitted fabrics from bamboo/cotton blended yarns tend to pill less.     

A novel approach for estimating the relation betweenK/S value and dye uptake in reactive dyeing of cotton fabrics

This paper focuses on the application of a novel mathematical limit approach derived forK/S values in reactive dyeing of cotton fabrics. The relation obtained from Kubelka-Munk equation is used because the Kubelka-Munk equation is the basic relationship among fabric reflectance, fabric dye content and dyestuff characteristics. The limit approach derived in a former paper is applied to the laboratory dyeings and the dyeing behavior of some reactive dyes on cotton knitted fabric has been obtained. The results of the laboratory experiments are discussed using the new mathematical approach. When the actualK/S values obtained from the dyeings and the calculatedK/S values derived by the limit approach are considered independently, it is observed that the limit relation is valid for low dye concentration applications. When theK/S values are calculated taking theK/S value of the initial dyeing concentration (0.1 % owf) as the starting concentration by applying the result of the derived limit approach, the calculatedK/S values fit with the ones obtained in actual dyeings. It is concluded that the novel approach presented in the paper can be used in calculating theK/S values when the initial dyeings at low dye concentrations are carefully carried out.     

Effect of washing cycles on behavior of core spun cotton/spandex interlock structures

Effect of machine washing on structural behavior of core spun cotton/spandex interlock fabrics made with high, medium and low tightness factors has been investigated. Results are compared with those for similar fabrics knitted from 100 % cotton. Structural behavior of cotton/spandex and cotton fabric samples was observed under full relaxation and washing treatments up to 10th cycle. Based on these data, dimensional constants (U-values) were predicted under 95 % significance level. Higher course and wale densities, stitch densities, dimensional constant values, linear and area dimensional shrinkages are reported with cotton/spandex interlocks. After treatment levels, cotton/spandex showed the dimensional constants with lesser CV %. With increasing fabric tightness, decreasing of length shrinkages and area shrinkages and increasing of width shrinkages are reported in cotton/spandex interlock structures. Cotton/spandex interlocks showed longitudinally and highly deformed shapes after treatments. Fabric tightness affects significantly on structural behavior of cotton/ spandex and cotton structures during relaxation.     

Deformation analysis of composite reinforcing fabrics through yarn pull-out, drape and shear tests

This study reveals a new method based on image processing of bias extension test results to determine shear angle that characterizes the shear properties of fabric reinforcements. This way the simple and exact determination of shear angle with conventional devices is solved. The new method was tested on fabric reinforcements made of carbon, aramid and glass fibers and the results were compared with that of two known versions of bias extension tests. The analysis of the relation between shear angle and other deformation properties that characterize spatial deformation behavior involved the comparison of shear test results with yarn pull-out and drape tests carried out with special methods.     

Enhanced visualization of simulated woven fabrics

The woven fabric graphics designed with available computer aided design (CAD) systems using different colored warp and weft yarns look quite different from the appearance of their actual fabrics. To enhance the visual effects of designed woven fabric graphics, this paper reports a modified CAD woven fabric system, which allows users to design a fabric using parameters including fabric weaves, yarn number, yarn material, fabric count, crimp shape of interwoven yarns, and illumination. This enhanced system can design both yarns and fabrics, and consider the transitional color effect around interweaving points of warp and weft yarns. Its simulation image quality of woven fabrics has been greatly improved, and several textile mills and universities are currently using this woven fabric design system.     

Introduction of normal preserving force into garment drape simulation for stable sewing process

A new force term for the particle based cloth drape simulation has been defined in this study. In the sewing process which is the starting point of a cloth drape simulation, usually large constraint forces are assigned along the sewing edges and this may generate a very stiff linear system which tends to diverge easily. Therefore, especially for a dynamic cloth simulation with a large time step, additional large damping should be introduced to stabilize the sewing process which slows down the process significantly. The new force term defined in this study was proved to be able to stabilize the sewing process without such a large damping by preserving the surface normal directions of mesh elements.