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We propose a measuring method of shear deformation in drape using three-dimensional (3D) scanning. We measured the local shear angles in fabric drape based on the Fabric Research Laboratories (FRL) drape test for woven fabrics using the proposed method. We investigate the effects of the relative positions of the node to the center grainlines that cross at the fabric center, and the bending and shear properties of fabric on the shear angles. To measure the local shear deformation, we obtained 3D drape shapes of four different fabrics with three to six nodes. We covered the obtained drape shapes using a fabric model composed of square cells that allowed shear deformation. By calculating the shear angles of the cells, we obtained the local shear deformation. We found that the FRL drape can be characterized by three areas, except for the flat areas of the support disks: (a) areas along the center grainlines with zero or small shear angles within 3°, which could result from single curvature bending; (b) areas in the bias directions with relatively large shear angles over 3°, which could result from double curvature bending; and (c) polygon edges connected by tangents of the support disk with relatively larger shear angles than their surroundings, which could result from both bending and shear deformation, such as folding and wrinkles. By investigating the relationships between areas with large shear angles and the bending rigidity/shear stiffness, we clarified that the bending rigidity indirectly affects the local shear deformation of drape. [ABSTRACT FROM AUTHOR]

The effects of fabric dimension on drape deformation are analyzed using a model of a circular segment cantilever for infinite shear stiffness (upper limit) and the deflection of strip cantilevers in radial directions for zero shear stiffness (lower limit). The drape shapes are determined by nondimensional parameters K and K′ in addition to the parameters m and m′, which are given by the ratio of the fabric radius and segment cantilever length, respectively. K and K′ are given by the segment cantilever length for the upper limit and by the differences between the radii of the fabric and support disk for the lower limit, with weights, and bending rigidity. The drape coefficient (DC) limits of fabrics are theoretically obtained using the model in three cases according to the relationship of m and m′. Even for different fabrics, the drape shapes are similar for the same m and K, or m′ and K′, in each case. The effects of dimension on fabric drape are therefore clarified theoretically. The obtained limits are experimentally verified for eight woven fabrics and one sheet. It is found that the DCs of samples are between the two theoretical curves of limits, although there are variations even for the same K or K′. The variations might be due to depressions between adjacent nodes or the presence of double-curvature deformation due to lower shear stiffness. The effects of dimensions in the drape test considering bending rigidity for infinite and zero shear stiffness are thus clarified theoretically and experimentally. [ABSTRACT FROM AUTHOR]

Physical stimuli from contacted objects are recorded by skin receptors and are transmitted to neural signals to the cerebrum to generate touch perceptions. Despite numerous studies having been conducted on the link between the physical properties of contacted objects and psychological sensations, factors besides the stimuli themselves have seldom been investigated. The contact method and acclimation to environmental factors, such as temperature and humidity, could affect the functions of responsible receptors, which, in consequence, might affect the touch perception. This study is designed around a series of experiments involving 226 human subjects adapted to the climate environments of six East-Asia cities. The results revealed that the contact method affected the responses of smoothness sensation but not the stimuli discriminations. This agrees with the hypothesis that both the slowly adapting type I (SA1) fiber and the Pacinian afferent (PC) fiber are responsible for smoothness sensation. SA1 fibers can function through passive touch because of a superficial location in the dermis, while PC fibers, which are located deeper in the dermis, are triggered during active touching. The effect of contact method on softness sensation is not significant because the responsible receptor is the SA1 fiber. The effects of acclimation to temperature and relative humidity were also investigated. Positive relationships were found with smoothness perception and negative relationships were found with warmth perception. This suggests that acclimation to temperature and relative humidity can affect the receptor thresholds and, in consequence, affect the touch sensation. [ABSTRACT FROM AUTHOR]

This study investigated the surface fitting ability of woven fabric under low tension using a new measurement method. The limit angle of shear buckling, the maximum shear angle, is defined as the surface fitting ability. To estimate the maximum shear angle, we measured the base radius of a spherical crown of woven fabrics while covering the spherical surface without wrinkles. The relationship between the maximum shear angle and base radius was calculated numerically. We constructed a new testing equipment to determine the surface fitting ability of fabric with an aluminum hemisphere set on a laboratory jack and acrylic boards with holes of varying size at the center. Nineteen kinds of woven fabric samples and three hemispheres of different radii were used to measure the surface fitting ability. The relationships among the maximum shear angle and mechanical and structural properties were investigated. Thickness, interlacing point density and shear stiffness showed high correlation with the surface fitting ability. Using these properties, a new prediction formula for surface fitting ability was proposed. The predictive values showed a good agreement with the measured values. Therefore, the proposed method and the prediction equation are useful for evaluating the surface fitting ability of woven fabrics. The effect of the sphere radius on the surface fitting ability was also clarified. [ABSTRACT FROM AUTHOR]

The effect of crimp on torsional rigidity of monofilament and cotton spun yarns was studied. Two kinds of polymeric monofilament yarns and four kinds of cotton spun yarns were examined. Different crimps were applied to the yarn using original crimp setting equipment. To fix the crimp, the polymeric monofilaments were treated with heat, and the cotton spun yarns were treated with steam. The test samples were then produced following two protocols: with or without the application of weight. The yarn torsional rigidities with crimp were measured using a torsional measurement device, and were compared with those without crimp. Almost no weight was applied to the cotton spun yarns to preserve the crimp during testing. The results with and without the application of weight were compared. For the monofilament yarns, the torsional rigidities of the crimped yarns had a linear relationship with the crimp ratio. For the cotton spun yarns, the torsional rigidities of the crimped yarns were smaller than those of the straight yarns. The smaller the yarn count, the smaller the yarn torsional rigidity. The effect of crimp on torsional rigidity differed according to the yarn counts. There was almost no difference in crimped yarn torsional rigidity between the straightened and non-straightened yarns after crimp setting. Therefore, there is a possibility that the change in yarn properties could have resulted from the bending of the fiber during crimp setting, and not from the shape of the crimp afterwards. [ABSTRACT FROM AUTHOR]

The effect of yarn torsional rigidity was verified on the Cooper model for fabric bending rigidity in any direction. We made five cotton fabrics with different weft densities and prepared three commercial fabrics as experimental samples. The torsional rigidity of yarn from the bobbin and that of yarn directly extracted from fabric were measured with a yarn torsional tester. The bending rigidity of yarn from the bobbin was measured using the same pure bending tester as used in fabric bending testing. The bending rigidity of thin fabric was calculated using torsional rigidities of yarns extracted from the fabric and showed better agreement with the experimental values than that calculated using the torsional rigidity of yarn from the bobbin. Indeed, measurements showed that the torsional rigidity of yarn from the bobbin was appreciably higher than the torsional rigidity of yarn from the fabric. This is due to the crimp in the yarn. The fabric bending rigidity can be predicted using the Cooper model with torsional rigidities of yarns extracted from the fabric. [ABSTRACT FROM AUTHOR]

A shear model for laminated fabrics bonded with dot-type adhesive interlining was proposed. The effect of fixing two or more interlacing points by adhesive on the shear stiffness of laminated fabric was taken into account. Using the proposed model, a prediction method for shear stiffness of laminated fabrics was proposed and verified experimentally. The increasing ratio (IR) of the shear stiffness of face fabric due to bonding interlining was defined as the ratio of difference between shear stiffness of laminated fabrics and pressed adhesive interlining, and the initial shear stiffness of face fabric. The relationships among the ratio of fixed interlacing points, IR and adhesive mass were investigated. It is clear that IR is affected by the adhesive fixing of adjacent floating yarns in addition to the fixing of interlacing points. The experimentally obtained IR for a face fabric shows a linear relation with adhesive mass. Then, a regression equation for IR was formulated as a function of the mass of the adhesive agent using a small number of interlinings. It was possible to predict shear stiffness of other laminated fabrics with the regression equation and adhesive mass. Furthermore, the shear stiffness values of laminated fabrics were predicted more precisely by dividing the regression area according to the mass of adhesive applied during interlining. [ABSTRACT FROM AUTHOR]

Liquid migration in woven fabrics was investigated by measuring the wicking coefficients of hydrophilic cotton and hydrophobic PVDF (polyvinylidene fluoride) monofilament fabrics and some other fabrics. The coefficients of fabrics with cotton warp yarns were essentially equal along the weft direction but differed along the warp because of variations in the warp yarn crimps. Then factors affecting the liquid migration along the weft direction were investigated, especially the effect of hydrophobic weft yarns, by using three different warp weave densities for fabrics with both cotton and PVDF weft yarns. The results showed that in the warp direction, liquid moved along longitudinal yarns and migrated to hydrophilic but not hydrophobic transverse yarns. In the weft direction, similar results were obtained for fabrics with cotton weft yarns. Fabrics with PVDF weft yarns, however, showed no migration through the longitudinal yarns, although liquid did move along the transverse direction of connected cotton warp yarns. The largest wicking coefficient was associated with the highest warp weave density. Liquid did not move through transverse yarns separated from one another. It is apparent that liquids can migrate along transverse, adjacent, in-contact hydrophilic yarns of fabrics incorporating longitudinal hydrophobic yarns. [ABSTRACT FROM PUBLISHER]

A new method was proposed for the measurement of in-plane capillary water flow within fabrics automatically. The method was based on the use of thermocouples to measure temperature changes as the fabric absorbed water. The wicking length of three different woven fabrics and two knitted fabrics in the warp, weft and 45° bias directions was measured using this technique. The wicking length was found to have a linear relationship with the square root of time, in agreement with the Washburn equation. Comparing the results with the data acquired using the horizontal Byreck method, the thermocouple technique was found to be suitable for the precise measurement of in-plane capillary water flow through fabrics automatically. Moreover, based on this method, the feasibility of estimating the water contents of fabrics from temperature differences generated during the flow process was also investigated. We found that it was possible to estimate the water content of a fabric, provided the moisture level is below the critical water content at equilibrium. This can be used to estimate the water content of fabric when it is worn. [ABSTRACT FROM PUBLISHER]

The bending rigidity of laminated fabric was investigated considering the positions of the neutral axes in bending for components in addition to the tensile and in-plane compressive moduli of components. Theoretically derived equations were proposed to obtain the position of the neutral axis and to predict bending rigidity of laminated fabric. Eight face fabrics, ten adhesive interlinings and eighty laminated fabrics of those combinations were used for experimental samples. Tensile properties, bending rigidities and thicknesses of samples were measured and used to investigate the validity of the theory. The positions of the neutral axes for the face fabrics were obtained and they were not close to the centroid of the fabric. The calculated bending rigidities of laminated fabrics using the obtained position of neutral axes were more agreed with the experimental ones than the results by the method without considering the position of neutral axis. Therefore, it was found that the bending rigidity of laminated fabric can be predicted more precisely considering the position of neutral axis. [ABSTRACT FROM PUBLISHER]

Sheepskin refers to the hide taken from a sheep and is composed of a layer of skin and the attached hair. It has unique fabric handle properties, and sheepskin quality assessments generally depend on a subjective hand evaluation via sensory test. Therefore, it is necessary to measure the fabric handle of sheepskin mechanically. For this study, we focused on perceived elasticity, and attempted to clarify the relationship between the tactile sensation and the mechanical properties of sheepskin through the development of a new three-dimensional tactile sensation measurement system (3D-TSMS) to measure the compression properties in three axial directions. For compression testing, the compression parameters were calculated as follows: compression linearity (LC), compressional energy (WC), compressional resilience (RC), compressional flexibility coefficient (αmax), pressure relieving energy (ΔEPR), and continuous mean deviation (CMD), etc. As a result of compression testing, the sheepskin samples which were highly rated for their perceived elasticity showed a convex curve during the initial compression process. In the statistical comparison analysis, LC, CMD, and ΔEPR showed a correlation to the perceived elasticity of sheepskin. [ABSTRACT FROM PUBLISHER]

The purpose of this study is to investigate the effect of pressing on bending rigidities of the face fabric, adhesive interlining and bonded composite fabric and verify the prediction method for bending rigidity of those. Predicting methods of bending rigidity for composite with face fabric and adhesive interlining based on laminated theory were verified with measured bending rigidities and thickness of samples. Bending rigidities and thicknesses of woven fabrics, adhesive interlinings and composites with those were measured by the KES-FB system. Polytetrafluoroethylene (PTFE) film was used for measuring mechanical properties of pressed adhesive interlining. Bending rigidities of adhesive interlinings became larger and thicknesses were reduced compared to those before pressing. Bending rigidities of face fabrics didn’t change though the thicknesses became thinner than before pressing. It was found that the case of considering mechanical properties of pressed face fabric and pressed interlining was more efficient to predict bending rigidity of composite with laminated model. [ABSTRACT FROM PUBLISHER]

A new creditable and effective multiaxial circular tensile tester (MACTT) with 16 load sensors installed around a circumference has been developed. The new tester could be used to measure tensile properties in various directions with one sample simultaneously under the same initial conditions. As a result, not only an error could be reduced, but also the experiment samples and time could be saved. The experimental results showed good agreement with the theoretical approximate values calculated based on Hooke's Law. We also compared the stress distributions obtained by the new tester with those tested by the Kawabata's Evaluation System (KES) instrument and the results confirmed that the new tester was theoretically reasonable and practically feasible for measuring orthotropic tensile properties of the fabrics with symmetrical structures, and that the new tester could also be used to test and evaluate the anisotropic tensile properties of fabrics with no orthogonal main axes. [ABSTRACT FROM AUTHOR]

Based on two basic assumptions: the Poisson's ratios vx, vy are constants; and tensile rigidities Ex, Ey are nonlinear functions of the stress, a new nonlinear theoretical model to describe the tensile behavior of fabrics based on the orthotropic theory is presented here. This new model was used to predict the uniaxial tensile properties of fabrics from the strip biaxial test by the Poisson's ratios vx, vy calculated from the strip biaxial experimental results. The uniaxial tensile experiments for plain knitted fabrics and for plain woven fabrics were carried out and the experimental results showed good agreement with the results predicted by the new model. It is the first time the relationship between the uniaxial tensile test and the strip biaxial tensile test has been established. The paper provides a simple and effective method for comparing the results obtained by different experimental methods. [ABSTRACT FROM AUTHOR]

The consumer is demanding more variety and personalization in apparel products. Personalization includes creating clothing that not only takes into account of variations in size, but also variations of the body shape itself. The traditional grading method is the current standard sizing system in the apparel industry. It starts with a base size which is then proportionally graded to create a multiple set of sizes. Although it caters for a limited number of sizes, this method does not include variations in body shape. In our research, we have developed a method of individual pattern making by modifying a traditional draping system so that it can be used in conjunction with modern three-dimensional modeling techniques. Individualized pattern making means customized pattern making for individuals. This method uses a five-step draping process. The steps are: (1) defining the surface shape; (2) setting grainlines; (3) fitting the fabric to the surface shape; (4) cutting of the three-dimensional surfaces; and (5) developing the three-dimensionally fitted fabric into a two-dimensional pattern. Our fitting process prevents or controls buckling when the limit angle of a fabric's ability to conform to a surface is exceeded. We do this entire process using computed geometrical models, rather than physically. Therefore we believe it has the potential to be more efficient and simple than other techniques. When we used this method to make a pattern for a tight skirt, we easily created complex curved lines automatically using this development method. When test subjects compared our skirt with a traditionally designed skirt, approximately 80% of the subjects indicated a preference for our skirt. Although this paper focuses on patterns made for dummies, our future research will focus on fitting to real human body shapes, [ABSTRACT FROM AUTHOR]

A new shear tester of woven fabrics based on the trellis shear model is described. The tester can be used to carry out shear deformation experiments under quite low tensile stresses. The values of shear rigidity tested on the new tester were compared with those tested on the uniaxial tensile tester and the KES (Kawabata's Evaluation System) instrument. The results confirm that the tester is more feasible and effective for measuring shear behavior in a natural state. This study establishes a foundation for constructing a universal instrument that can be used to measure shear deformation under any conditions. [ABSTRACT FROM AUTHOR]