Fabric Bending Research Articles

Research on the new method for visualizing bendability testing of fabrics in multiple directions

PurposeThe current bending test method can only test the bending performance of fabric in one direction at a time. It is not possible to directly observe the bending morphology of fabrics in different directions, and it is necessary to cut samples and repeat the test several times, which takes more time. For this situation, a multidirectional visualization of the fabric bending test method is proposed, using which multiple results can be obtained at one time and the fabric bending can be visualized.Design/methodology/approachAbout 17 fabrics are tested using a self-designed device. The fabrics are cut into special triangles and multiple sets of results in three directions are obtained at once using the device. The experimental specimens are photographed from the above and the transverse elongation length, bending projection area and circumference are extracted after image processing.FindingsThe results show that the correlation coefficients of transverse elongation, bending projected area and circumference are good with the bending length measured by the cantilever method. In which, all three indicators are positively correlated with the bending length. This indicates the good feasibility of the new method.Originality/valueThis method can get the bending index of fabrics in three directions, with five samples in each direction at one time. Meanwhile, it can also visualize the flexural differences between different fabrics and directions of the same fabric. It can provide more efficient testing means for the textile testing field, and the testing efficiency is 15 times of the existing method, which has better theoretical significance and practical values.

Concave and convex small radius bending behavior of single and multiple layers reinforcement fabrics

Multilayer reinforcement fabrics are increasingly used for manufacturing structural polymer composites. In liquid molding processes, dry reinforcement fabrics are draped on a mold first, and infused with a liquid resin such as an epoxy in a subsequent manufacturing step. This presents major advantages in terms of operational flexibility and costs. However, draping multilayer reinforcement fabrics on complex mold geometries is challenging. Small radius mold corners constitute a major manufacturing challenge as they lead to variability in dry fabric positioning and resin-rich corners in polymer composite parts. Spring-back of fabrics bent over or into single curvature mold corners is a widespread industrial concern. However, contrary to draping over double-curvature surfaces, bending spring-back from convex or concave single-curvature corners has received very limited attention. No testing method is available. This paper quantifies reinforcement fabric bending spring-back. Single and multiple layer stacks were bent along three directions over convex and into concave 90° corners with five radii spanning 1.59 mm to 12.70 mm. In all cases, five replicated tests enabled variability quantification. Fabric stacks were also quantified using cantilevered bending tests for comparison purposes. Mold radius was found to affect the behavior to a larger extent than testing direction, number of layers or use of a binder.

Machine learning in optimization of nonwoven fabric bending rigidity in spunlace production line

Spunlace nonwoven fabrics have been extensively employed in different applications such as medical, hygienic, and industrial due to their drapeability, soft handle, low cost, and uniform appearance. To manufacture a spunlace nonwoven fabric with desirable properties, production parameters play an important role. Moreover, the relationship between the primary response and input parameter and the relationship between the secondary response and primary responses of spunlace nonwoven fabric were modeled via an artificial neural network (ANN). Furthermore, a multi-objective optimization via genetic algorithm (GA) to find a combination of production parameters to fabricate a sample with the highest bending rigidity and lowest basis weight was carried out. The results of optimization showed that the cost value of the best sample is 0.373. The optimized set of production factors were Young’s modulus of fiber of 0.4195 GPa, the line speed of 53.91 m/min, the average pressure of water jet 42.43 bar, and the feed rate of 219.67 kg/h, which resulted in bending rigidity of 1.43 mN {mathrm{cm}}^{2}/cm and basis weight of 37.5 gsm. In terms of advancing the textile industry, it is hoped that this work provides insight into engineering the final properties of spunlace nonwoven fabric via the implementation of machine learning.

Novel measurement of fabric bending anisotropy

PurposeUnder the widely used testing methods for fabric bending behavior, only one result for one direction can be obtained by using one fabric which is low efficient. To obtain fabric bending anisotropy, it is necessary to conduct a great many testing experiments. The purpose of this paper is to investigate a novel, efficient and visual method that can measure fabric bending anisotropy.Design/methodology/approachFabrics are first cut into special shapes with eight strips including four directions, 0°(warp direction), 90°(weft direction), 45 and 135°(true bias), then are put onto the self-designed instrument. After that a camera is used to take picture from the right above the prism. New parameters, projection area, projection length, projection length, falling height and falling index (S, L, H and I in short) are obtained. Furthermore, standard deviation of them (SDS, SDL, SDH and SDI in short) are extracted for the characterization of bending anisotropy.FindingsResults show that the new method has good feasibility and S, L and I can be used to express fabric bending property well. Of all the four new parameters, SDL has the highest correlation with SD of bending length, SDS the second and SDH the third. That is, SDL can characterize bending anisotropy best. Taken convenience of data acquisition and correlation into consideration, bending length L is the best parameter. Average L and SDL in four directions can be combined to express the comprehensive bending behavior of fabrics.Originality/valueThe new method can measure and characterize both the fabric bending property and bending anisotropy. Besides its high efficiency, it can display fabric bending or bending anisotropy visually and directly.

New method for measuring fabric multi-directional stiffness and drape

A method that can measure fabric multi-directional bending performance and draping property simultaneously is proposed and new parameters, projection area and projection length are extracted for the characterization. A total of 30 fabrics are tested with the new method as well as with the cantilever test and umbrella method. Results show that the new parameters have good correlationship with bending performance and draping property. Bending performance in four directions and two groups of bending indexes in each direction can be acquired with only one fabric sample. Compared with the conventional cantilever method widely used, the method proposed in this article is more efficient and time-saving. At the same time, it can test fabric drape in one specific direction. Therefore, it can combine the test of fabric bending and draping performance into one.

Study on thermal, mechanical, and wettability properties of three-dimensional weft-knitted spacer fabrics with various silica aerogels coating

This study investigated the thermal, mechanical, and oil absorption-retention properties at various temperatures (20°C, 30°C, 40°C, 50°C, and 60°C) of three-dimensional (3D) weft-knitted spacer fabrics with optimal performance of silica aerogel coating that demands exceptional attention. Silica aerogels and (silica aerogels + poly(vinyl-alcohol)) sols were prepared and coated on 3D weft-knitted spacer fabrics to study and compare the basic properties, i.e. thermal resistance, thermal conductivity, tensile strength, initial modulus, compression, bending rigidity, wettability, oil absorption, and retention capacity. The scanning electron microscopy and Fourier transform infrared spectroscopy studies were completed to understand the influence of both coatings on 3D weft-knitted spacer fabrics such as surface morphology and molecular interaction. The tensile, bending, and compression tests of 3D weft-knitted spacer fabrics were accomplished to check their durability, bendability, and compressibility. All the coated samples (both silica aerogels and (silica aerogels + poly(vinyl-alcohol))) showed greater thermal resistance (0.0971 ± 0.0003 m2 KW−1 and 0.0912 ± 0.0005 m2 KW−1) and lower thermal conductivity (0.0309 ± 0.0001 Wm−1 K−1 and 0.0329 ± 0.0002 Wm−1 K−1) with better thermal stability than the uncoated samples, most specifically coated sample 5. Besides, coated sample 5 exposed higher oil absorption ((7.91 ± 0.06 g/g and 7.88 ± 0.06 g/g) and (7.56 ± 0.04 g/g and 7.53 ± 0.04 g/g)) and retention ((90.10 ± 0.53% and 89.07 ± 0.55%) and (92.47 ± 0.49% and 91.43 ± 0.47%)) capacity for vegetable and engine oil in all conditions, especially at 40°C. The outcomes demonstrated that both coatings played a vital role in the thermal, mechanical, and wettability properties of 3D weft-knitted spacer fabrics with statistically significant performance ( p < 0.05). Moreover, these new types of sorbents (3D weft-knitted spacer fabrics) have better consequences in most cases than conventional knitted, woven, and nonwoven sorbents. Hence, these 3D weft-knitted spacer fabrics could be used for industrial applications as eco-friendly and multifunctional oil sorbent materials.

Optimisation of bending and shear rigidities of woven fabrics using hybrid DOE-NSGA-II approach

Bending and shear rigidities of woven fabrics depend on various materials and structural parameters. Achieving low bending rigidity and high shear rigidity in woven fabrics is a challenging and complicated task. In this work, engineering design of woven fabrics was optimised with respect to bending and shear rigidities using design of experiments (DOE) and non-dominated sorting genetic algorithm II (NSGA-II). The relationships between input parameters (proportion of fibre, yarn count and fabric sett) and rigidities of fabrics were obtained using Box-Behnken DOE method. The NSGA-II was used to determine the Pareto optimal front for low bending rigidity and high shear rigidity. The user can choose any option from the Pareto optimal front based on the end-use requirement. For the validation of the proposed approach, two engineered fabrics were produced using the optimised values of input parameters. The results demonstrated that target values and achieved values of rigidities are reasonably close to each other with average error of 6.24% and 3.33%, respectively. The proposed method can pave the way for intelligent manufacturing of woven fabrics in industrial scale.

A statistical prediction model for pilling grades of blended worsted fabrics based on fabric bending rigidity

A laboratory statistical tool based on fabric bending rigidity and weft yarn count to predict fabric pilling grades of blended worsted fabrics is proposed. Multiple regression analysis is performed to obtain three dependent models as evaluation tools for pilling tendency. Three different materials of weft yarns; 60/40% blend of wool/polyester fibers, 35/65% blend of viscose/polyester fibers and 20/40/40% blend of viscose/polyester/acrylic fibers were considered. Moreover, four different counts of weft yarns, different ranges of picks per inch (44–50) and three structures of fabric weave (Plain, twill and satin) were used. Results showed that the first model recorded the best performance to predict fabric pilling grades when considering coefficient of regression analysis was (R2 = 0.92) and Mean Square Error was (MSE = 0.074). Moreover, measuring of fabric bending rigidity and counts of weft yarns is sufficient to be an indicator for predicting the fabric pilling tendency.

Justification of an approach to cellulase application in enzymatic softening of linen fabrics and clothing

We propose the final softening finishing of textile products based on a complex of modifying effects on a highly ordered cellulose backbone of the secondary cell wall G-layer or on a mesh corset of microfibrillar cellulose in the primary cell wall. We suggest using polypeptide molecule sizes and the strength of polypeptide molecule adsorption binding on a model solid-phase substrate as parameters of the structurally regulated action of cellulase preparations. The article presents an analysis of 11 cellulase preparations as groups of weakly, tightly and medium adsorption enzymes, and also groups of volumetric, peripheral or combined activity manifested in the fiber structure. We show the regularities of enzyme property influence on the fiber pore structure development, changes in the parameters of the fabric bending stiffness and breaking load and technological shrinkage for two modification modes: liquid treatment with flax fiber swelling or low-modulus application solution. For the liquid method of treatment (with a bath module of at least 10) it is recommended to apply highly adsorbable cellulases ( A > 50%), in which the content of molecules with a globule size less than 30 nm does not exceed 15%. For the low-modulus method of treatment it is recommended to use enzymes with the adsorption capacity of at least 40% and a low content of small-sized fractions (no more than 25%). The recommended treatment variants ensure a three to four-fold bending stiffness decrease at the mechanical strength loss of not more than 15% and shrinkage of linen fabrics not more than 0.5%.

Characterizing the macroscopic response and local deformation mechanisms of a unidirectional non-crimp fabric

The macroscopic response and local deformation mechanisms of a warp stitched heavy-tow unidirectional non-crimp fabric (UD-NCF) was characterized. Quasi-static uniaxial tests captured the fabric in-plane longitudinal, transverse, and shear deformation response where digital image correlation was employed. The fabric bending response was captured through modified cantilever tests. Off-axis extension tests conducted along 30°, 45° and 60° bias directions revealed that extension and contraction of the polyester stitching web and resulting transverse compression of the carbon fiber tows and inter-tow sliding were the dominant local deformation mechanisms. At a bias angle of 30°, the extent of inter-tow sliding increased when compared to a bias angle of 45° leading to earlier onset of fabric shear locking, while at a bias angle of 60° shear locking also occurred sooner. Shear angle maps and strain profiles at different bias angles further revealed the notable inter-dependency between the fabric shear, longitudinal and transverse deformations, which was governed by the interactions between the stitching and carbon fiber tows. The distinct out-of-plane bending behavior of the fabric reinforcement along longitudinal and transverse directions was also captured and quantified. The study provided a comprehensive characterization of the UD-NCF, which is critical for the development of constitutive models.

Effect of fibre cross-sectional shape on bending behaviour of yarns and fabrics; part I

To study the effect of fibre cross-sectional shapes on the bending behaviour of continuous multifilament polyethylene terephthalate (PET) yarns and corresponding fabrics, a circular cross-sectional shape has been taken as reference shape. To mimic the natural fibres in different ways, the cross-sectional shape is an important parameter in this regard. Different cross-sectional shapes like circular, trilobal, rectangular, plus, double flange dumble shape, octagonal, hexalobal, square and trilobal plus or Y-shape were selected for the study. The linear density of single filament and yarn were kept constant (i.e. 76/48/0) in all cross-sectional shapes. The area of cross section was approximately constant for all shapes. The theoretical bending rigidity was calculated for all cross-sectional shapes about its neutral axis. The experimental BR ratio concerning reference circular cross section of fibre was compared with the theoretical BR ratio. It is assumed that individual filament is free to bend in fibre assembly having zero twists. All yarns were converted to fabric having constant areal density. The yarn bending behaviour is compared with fabric bending behaviour to study the effect of cross-sectional shapes on bending behaviour.

Soft robotic fabric gripper with gecko adhesion and variable stiffness

Fluid-driven soft grippers possess conformable grasping characteristics that differ from their rigid counterparts. Despite advances, their inherent low-stiffness due to constituent materials causes them to be inferior in many high-load applications. Existing fabrication methods of soft grippers that mostly rely on molding silicone elastomers, despite being simple, are not easily scalable. This article presents the design of a soft robotic fabric gripper that can be fabricated by a facile and highly scalable process of apparel engineering. The proposed robotic gripper features a multi-fingered design that comprises hydraulic-driven, sheet-shaped fabric bending actuators. Its performance is enhanced by incorporating a bio-inspired gecko adhesive and a thermo-responsive variable stiffness filament. Experimental studies demonstrate that adding the variable stiffness filament and gecko adhesive improves the holding force of the gripper up to 655 % and 507 % in the gripping and pull-out configurations, respectively. The variable stiffness filament features a relatively good cooling speed of only 31 s by ambient cooling. A simple analytical model was also developed to characterize the deformation of the fabric bending actuators. To monitor the gripper bending motion, a new soft fabric sensor comprising a conductive composite of liquid metal and carbon particles was developed. The sensor was configured in a sheet-like shape and can be easily integrated into the gripper, which has been usually absent for other fabric grippers. The materials employed by this gripper design are commercially available for a reasonable budget, enabling the gripper to be both cost-effective and have potential applications where both gentle grasping and high load capacity are required.

Simulating the effect of fabric bending stiffness on the wrinkling behaviour of biaxial fabrics during preforming

A macroscopic finite element model has been established to investigate the forming-induced wrinkling behaviour for bi-axial fabrics. Results indicate that using a linear bending model with a constant bending stiffness produces unrealistic wrinkle patterns in the fabric plies. A non-linear bending model produces more accurate forming induced wrinkle patterns compared to experimental data, since the bending stiffness parameter is varied as a function of the applied forming load to account for the onset of fibre buckling. Areas of high in-plane shear are more likely to induce out-of-plane wrinkles, indicating a positive correlation between wrinkling onset and shear deformation. A new methodology has been developed to quantitatively evaluate the severity of fabric wrinkles based on the FE simulation results. The distance between the surface of the preform and the mould tool is used to locate areas with out-of-plane defects, using the principal curvature to isolate wrinkles from areas of fabric bridging (poor conformity).

Effect of ethylene acrylic acid co-polymer coating on bending and thermal properties of cotton fabrics

Bleached cotton fabric and a water-based polymer coating solution made from ethylene acrylic acid co-polymer which is multifunctional polymer material is used in this experimental study to increase the bending and thermal properties of cotton fabrics. Roller coating and Exhaust methods is used to apply ethylene acrylic acid co-polymer solution on the cotton fabric surface. The coated fabric surface is then cured and dried at a temperature of 60–90 °C using a laboratory oven. The developed fabric samples are then taken for testing for its bending and thermal properties using a fabric stiffness tester and DSC thermal analyzer. The chemical composition and its chemical group finger print analysis is also ascertained using FTIR spectra. The fabric stiffness results of coated fabrics show increased bending properties and the thermal property results from DSC and plotted graphs prove its robustness and resistance to heat. However, Roller coating method seems to be more efficient than exhaust method with respect to the application method employed for coating ethylene acrylic acid co-polymer.

Fabric Hand Sew Ability Characterization (Dept.T)

This investigation presents an experimental study of the effect of bleaching-dyeing finishing on fabric surface characteristics, i.e. Hand, tactile, and Sewability characterization Instrumental measurements was based on measuring fabric tactile properties as a function of, fabric drape ratio, and fabric bending length, while fabric Sewability was studded in terms of fabric resistance to needle penetration, i.e. fabric Sewability, and fabric hand was assessed by determination the values both of the maximum fabric pulled force and work done through a conical shaped funnel. It was found that, fabric properties such as: bending length, drape ratio, strength, extension, hand, and Sewability, decrease with the increasing the concentration of both polyethylene and Fatty Acids softeners. The obtained results has shown that correlations between fabric hand-tactile-Sewability are quite high.

Effect of laser treatment on pigment printing on denim fabric: low stress mechanical properties

In textile and fashion industry, it is common to combine laser treatment and pigment printing processes for creating special design and aesthetic effects. Other than aesthetic effects, comfort is also a concern to the customer. This paper examines comfort properties, in terms of low stress mechanical properties, of laser treated and pigment printed denim fabric. Tensile, shearing, bending, compression and surface properties were examined by Kawabata evaluation system for Fabric under standard procedure. It was noted that tensile, shearing, bending and compression properties of the denim fabric were affected by laser treatment and pigment printing. This influence could be caused by action of the laser during the treatment as laser can damage the fabric and yarn, and can also burn the fabric surface. The pigment used in printing forms a thin layer on fabric surface making the denim fabric more rigid and difficult to deform. Moreover, surface properties of denim fabric samples were not affected by laser treatment or pigment printing and nor was there any effect of the two combined treatments. The denim fabric samples became smoother and had an even surface.

Contribution of bending and shear behavior of woven fabrics in the characterization of drape

The drape, bending and shear properties of a group of woven fabrics have been studied along with the effects of fabric structural parameters on these properties. In addition, the influential effect and relative contribution of bending and shear behavior in the determination of drape is also evaluated. The results show that the crossing over firmness factor, which is related to the weave structure and also the weft density, significantly influences the drape, bending and shear behavior of fabrics. With the aid of linear regression analysis of the relationship among drape coefficients, bending and shear modulus, the correlational model for prediction of drape based on bending and shear has also been developed. With regards to this model, it can be claimed that the relative contribution of fabric bending in determination of drape is greater than that of shear.

Comparison of sewn fabric bending rigidities obtained by heart loop method: effects of different stitch types and seam directions

Sewing quality is an important factor that contributes to the overall quality of an end-product. Sewing quality compro - mises different components such as bending, seam strength, seam slippage, elasticity etc. Among these components, bending has a special importance because of causing changes in appearance, sensorial comfort and drape of a garment. Therefore, in this study, effects of stitch type and seam direction on the bending rigidities of sewn fabrics were evaluated and compared. A polyester woven fabric which is suitable for sportswear was sewn with three basic stitch types (lock stitch, chain stitch and overlock stitch), in 5 different directions (warp, weft, 30°, 45° and 60° angles). As reference, samples without stitches were tested, too. Bending properties of samples were determined via heart loop method. According to the results, sewing increased the fabric bending rigidity. The degree of bending rigidity increment was dependent on the stitch type. Highest bending rigidity values were obtained for overlock stitched samples those were approximately 4 times higher when compared to non-sewn reference samples. Thickness of sewn parts was in accordance with the bending rigidity results. For oriented seams, bias sewing especially for 45˚ oriented samples, showed the most advantageous bending results. This study showed the usability of heart loop method for sewn samples via consistent results for different stitch types and seam directions.

Engineering of sustainable clothing with improved comfort and thermal properties-A step towards reducing chemical footprint

Clothing is among the basic needs of human and this has led to tremendous growth in the textile sector. However, huge amounts of hazardous chemicals used in the clothing industry have raised concern in recent years. Due to the increasing awareness in regards to environmental pollution and personal health, particularly in the textile manufacturing, there has been a need for sustainable manufacture of clothing with reduced exposure to the toxic chemical. This research presents a new domain of core-spun yarn (hybrid structure), developed to improve fabric handle, comfort and thermal properties without the application of softening chemicals. Fabrics made up of spun over spun hybrid yarns (SSHY) exhibited remarkable reduction in fabric stiffness. There was approximately 50% reduction in fabric bending rigidity in the case of SSHY fabric in comparison with ring-spun conventional yarn (RSCY) fabric. Notably, there were improvements in the fabric tear strength and other physical parameters.

Analysis of Mechanical Properties of Carbon Fiber Reinforced Concrete based on Ansys Composite Model

The present work is an experimental account of the way in which several machine settings, particularly cylinder knock-over and dial-height, influence fabric dimensions, course length, bending behavior and load extension of fabrics produced on a circular knitting machine. The results show that there are certain optimum settings for such variables as knock-over depth and dial-height for producing fabrics with optimum liveliness, dimensions and bending behavior. This study confirms the suggestion that due to the asymmetry of fabric take-down on circular double jersey machines, it is not possible to produce a fabric with identical properties on the face and back sides. No conclusive evidence of robbing yam from the cylinder loops to dial loops which cause asymmetry in the fabrics could be found but alternate suggestions were examined.