Comparison of bending properties Co-woven-knitted and Multi-layered biaxial Weft-knitted fabric reinforced composites

Co-woven-knitted (CWK) fabrics and multi-layered biaxial weft knitted (MBWK) fabrics were prepared using glass filaments as both the warp and weft yarns and high tenacity polyesters as the stitch yarns with the same stitch length. Then the polyethylene resin was injected into the fabrics by vacuum assisted resin transfer molding to produce composites. Specific bending stress-displacement curves in the course and wale directions of the CWK fabric reinforced composites and the MBWK fabric reinforced composites were analyzed and their bending properties were also compared. Results indicate that the initial segments of all the specific bending stress-displacement curves for the CWK and the MBWK fabric reinforced composites are linear; then the specific bending stresses decrease with the displacements in a wave-like manner until sample destruction. The CWK fabric reinforced composites show plastic failure in course and wale directions, while the MBWK fabric reinforced composites show first fragile failure then plastic failure in course direction and show plastic failure in wale direction. Bending properties in the course direction of the CWK and the MBWK fabric reinforced composites are different from those in their wale direction, respectively. The CWK fabric reinforced composites are of smaller anisotropy than the MBWK fabric reinforced composites. By designing the buckling and distribution of the warp and weft yarns, the axial properties difference can be shortened.     

Crimp analysis of worsted fabrics in the terms of fabric extension behaviour

Inside a woven fabric structure, warp and weft yarns acquire crimp as a result of yarns interlacing according to the weave pattern. Since warp and weft yarns are oriented in two perpendicular directions, applying tensile load in one direction causes extension in the load side and fabric contraction in the opposite direction. This process was investigated in this study by using an image processing procedure and it was found that fabric’s extension is in coincidence with yarn’s de-crimping process in the same direction. After the de-crimping stage, yarns in the load direction will be extended and at the same time crimp in the other direction will be increased, until jamming phenomenon happens in the fabric structure. The crimp interchange between warp and weft yarns follows a three-order polynomial function with a turning point in which the yarns in the load direction have no crimp.     

Effect of weaving process on tensile characterization of single and multiple ends of air-entangled textured polyester yarns

The tensile properties of air-entangled textured polyester single and multiple yarn ends before and after weaving were analyzed. The effects of weaving process considering fabric unit cell interlacement and number of yarn ends were evaluated by regression model. For this purpose, plain, ribs and satin woven fabrics were produced. The yarns were raveled from fabrics, and the tensile tests were applied to these yarns. The developed regression model showed that the number of interlacement and crimp ratio on the warp and weft yarns influence their tensile strength. Tensile strength of raveled yarns decreased compared to that of the bobbin yarn due to the effect of weaving process. This property degradation on the ravel yarns considered process degradation. Generally, when the number of warp and weft yarn ends increases, the warp and weft yarn tensile strengths for each fabric type decrease, whereas the warp and weft yarn tensile elongations slightly increase. The results from regression model were compared with the measured values. This study confirmed that the method in the study can be a viable and reliable tool. The research finding could be useful those who work on preform fabrication.     

Predicting tensile strength of yarns required for producing PET/Cotton blended woven fabrics of a pre-defined tensile strength

This study was aimed at developing statistical models for the prediction of tensile strength of warp and weft yarns required for attaining a pre-defined strength of PET/Cotton blended woven fabrics. The models were developed based on the empirical data obtained from carefully developed 234 fabric samples with different constructions using 15, 20, and 25 tex yarns in warp and weft directions. The prediction ability and accuracy of the developed models were assessed by correlation analyses of the predicted and actual warp and weft yarn strength values of another set of 36 fabric samples. The analyses showed a very strong ability and accuracy of the developed statistical prediction models.     

Evaluation of the structural properties of plain fabrics woven from various fibers using Peirce’s model

Peirce’s fabric model has been widely used to predict the structural behavior of various plain woven fabrics. The structure of plain woven fabric can be defined in terms of the warp yarn number, weft yarn number, warp fabric density, weft fabric density, warp crimp, and weft crimp. The warp and weft yarn diameters are calculated from the warp and weft yarn numbers, and the effective coefficient of the yarn diameter is defined by using this model. We have investigated structural properties, such as the effective coefficient of the yarn diameter, yarn crimp, and fabric thickness for two different fabrics in which the constituent yarns are assumed to be either incompressible or compressible. This model is also applied to various plain fabrics woven from cotton, rayon, wool, linen, nylon, acetate, polyester, and silk yarns.     

Development of moisture transition ability on porous complex structured woven fabric with convergence of pattern,porosity, and plasma technology

A porous complex structured woven fabric was manufactured to maximize the moisture transition ability of the prepared fabric by increasing the absorptive property of the fabric through surface modification using plasma, which is a dry modification method. Porous single and complex structured woven fabrics were produced by applying pattern, porosity, and plasma technology, including fabric patterning based on the sheath/core complex structure, the formation of porosity by removing the weft thread or warp thread, and hydrophilic surface treatment using plasma and the improvement in water absorption of different fabrics by the porous and plasma treatment was investigated. Therefore, two different types of fabrics were prepared. One is the porous single structured FAB-SINGLE fabric which was taken out in the direction of the Polyester (PET) warp thread of a general single structure to form a porous. Another is FAB-COMPLEX fabrics that the water-soluble polylactic acid (PLA) yarns with a 1.7 to 2.0 times longer absorption distance than that of PET yarns were inserted into the weft threads, and the PLA yarns were dissolved in a solvent to form the porous complex fabric. And then the physical properties and water absorption of the two types of fabric were compared after the plasma treatment. The results showed that when the FAB-SINGLE fabric, which has porosity induced by the removal of the warp threads in a certain gap, was plasma treated for 5 min, the contact angle was decreased to the extent that a measurement of the contact angle was impossible, whereas the fabric that had not undergone a plasma treatment had a contact angle of 123.6 o. The contact angle of the FABCOMPLEX with porosity caused by the dissolution of the PLA yarns was reduced from 76.8 o to 0 o after 3 minutes of a lowtemperature plasma treatment, indicating that the hydrophilic property was increased. In addition, the water absorption measurements showed that the absorption height was increased from 2.3 cm of the fabric sample that had not been treated with plasma to the highest absorption height of 8.3 cm, suggesting that the water absorption also increased with the improvements in moisture transition ability by the plasma treatment. The physical tensile strength of the fabrics was not changed by the plasma treatment, despite the changes on the fabric surface, suggesting that the combination of double complex structures and the plasma treatment helped improve the water absorption.     

Effects of loom characteristics on the physical properties of PET fabrics for emotional clothing

The fabric defects complained by garment manufacturers are stop marks, streaky phenomena on the warp direction, thickness variation and color differences between edges on the right and left sides of the fabrics, which are partly due to the tension variation of warp and weft directions. It is well known that these defects are related to the difference of fabric mechanical property according to the loom characteristics and fabric position such as center and both edges parts of the fabric, which affect garment formability and wearing performance of garment. This research is focusing about which factor is dominant for the difference of fabric mechanical properties which affects garment formability and wearing performance between loom characteristic factor and fabric position factor such as center and both edges of the fabric, which is affected by warp and weft tensions. For this purpose, two kinds of looms were selected, and warp and weft tensions during weaving were measured and the mechanical properties of the fabrics woven by two kinds of looms such as tensile, bending, shear, compression and surface properties were also measured according to the positions such as center and both edge parts of the fabric. These fabric mechanical properties were examined with warp and weft tensions according to the looms and were also analyzed according to the positions of the fabric woven by two kinds of looms. The warp tension on the vicinity of center parts of the looms was much higher than those on the vicinity of both edges of looms. It revealed that the warp tension difference makes differences of fabric mechanical properties such as tensile, bending, shear and surface properties except compressional property. And the differences of these mechanical properties according to the fabric positions and looms seem to make homogeneity of the fabric hand and tailorability of garment deteriorating.     

Investigating ballistic impact on fabric targets with gripping yarns

The purpose of the research is to investigate the fabric structure (with gripping yarns) in influencing ballistic performance aiming to improve the ballistic performance of the currently used body armour materials. Thirteen different fabrics having gripping yarn were designed along fabric warp and/or weft directions. Their ballistic performance in terms of energy absorption has been studied and comparisons made among the single layered fabrics and between the two double layered fabrics, as well as to the conventional used a plain woven fabric for both cases. It was found that fabrics with gripping yarns have improved fabric ballistic performance. The inter-jointed two-layer fabric performed better than the un-jointed two-layer fabric, and it showed a 16.6 % increase in the energy absorption. The implication of the research is that body armour can be made lighter without reducing ballistic impact performance by using gripping yarns.     

A study on the structural properties of plain fabrics using the lenticular model

The structural properties of a plain fabric were considered using the lenticular model. The structure of a plain woven fabric can be defined in terms of warp yarn number, weft yarn number, warp fabric density, weft fabric density, warp crimp, and weft crimp. Many structural variables of the plain fabric could be calculated by the lenticular model using these terms. Also, this model can be used to explain the geometry of the flattened yarns that occur during the weaving process. Flattening factors of threads for various types of fibers were calculated, compared, and explained with the number of yarn twist. Flattening factors were found to affect the structural variables of the fabric such as fabric thickness, air permeability, and yarn crimp. Yarn crimp was also studied with variation of the structural variables of the fabric.     

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.     

Analysis and tensile characterization of air-entangled textured polyester woven fabrics depending on interlacement and yarn sets

The aim of this study was to understand the failure mechanism of two dimensional dry fabric structure considering yarn sets and interlacements. For this purpose, data generated on air-entangled textured polyester woven fabric under the simple tensile load and analyzed by developed regression model. The regression model showed that warp and weft directional tensile strengths of satin fabric were higher than those of plain and rib fabrics in unravel sample. This might be related to the number of interlacements of the fabrics. There was not a considerable difference between warp directional tensile strength of ravel and unravel satin fabrics, whereas weft directional tensile strength of ravel satin fabric decreased rapidly with respect to its unravel form. The satin fabric showed the highest warp directional tensile strength among the others. The lowest weft directional tensile strength was received from ribs fabric. In semi-ravel sample, all fabrics showed low warp and weft directional tensile strength values except in plain fabric. Warp directional tensile elongation of plain fabric was the highest in unravel sample. Satin fabric showed the highest warp directional tensile elongation in the ravel sample. Warp directional tensile elongations of all the fabrics in the semi-ravel sample became low. Weft directional tensile elongation of satin fabric was the highest in unravel sample. In addition, satin and plain fabrics showed the highest weft directional tensile elongations in the ravel sample. Weft directional tensile elongations of all the fabrics in the semi-ravel sample became low except in ribs fabric.     

Reflectance prediction of colored polyester fabrics by a novel formula

This paper focuses on the reflectance prediction of colored (unicolored) fabrics considering relationship between fractional reflectance values and cover factors of fabrics woven from polyester yarns. A novel equation for the calculation of relation between fractional reflectance and cover factor was proposed and usage of the equation was assessed by reflectance measurements. 48 dyed polyester fabrics having different constructional parameters were used and fabrics differed from each other by their cover factors. Warp yarn type and count, warp density and warp yarn twist were the same but weft yarn count, weft yarn fiber count and weft density were different for the fabrics in experimental sub-groups. The reflectance measurements were conducted on the dyed fabric samples as well as on the individual yarn systems (warp and weft) of the same fabrics. The proposed equation was tested according to different fabric constructional parameters and reasonable results with the experimental data were obtained. The possibilities of general use of derived mathematical relations between theoretical and measured reflectance values were researched. The relation obtained was used to explain the effects of different constructional parameters on reflectance behavior of fabric surfaces.     

Assessing the relationship among fabric constructional parameters, fractional reflectances and cover factors of polyester fabrics by experimental and mathematical methods

This paper focuses on the assessment of the relation among constructional properties, fractional reflectances and cover factors of fabrics woven from polyester yarns. A novel equation for the calculation of the relation between fractional reflectance and fabric cover factor was proposed and the usage of the equation was assessed by reflectance measurements. 48 polyester fabrics having different constructional parameters were used and the fabrics differed from each other by their cover factors. The warp yarn type and count, warp density and warp yarn twist were the same but weft yarn count, weft yarn fiber count and weft density were different for the fabrics in the experimental sub-groups. The reflectance measurements were conducted on the pretreated but undyed fabric samples as well as on the individual yarn systems of the same fabrics. Fabrics with the same cover factors exhibited different fractional reflectances. Reflectances were found to be dependent on the cover factor as well as on yarn fiber fineness, yarn count, yarn density and fabric weave. The changes in crimp of the yarns according to different construction parameters also governed the changes in fractional reflectances of fabric surfaces. The proposed equation was tested according to different fabric construction parameters and it was concluded that fiber fineness and weave pattern were among the most important parameters which govern the total light reflectances from the fabric surfaces, although they are not incorporated in the calculation of the fabric cover factors. The proposed equation was used to explain the effects of these components on the reflectance behavior of the fabric surfaces and on fabric cover.     

Mechanical characterization of flocked fabric for automobile seat cover

In this study, the tensile and tearing properties of substrate, substrate with adhesive and flocked fabric were studied with developed regression model which explains the relationships between fabric forms and tensile and tearing strength of the flocked fabrics. Warp and weft tensile strengths of wet flocked fabric are generally higher than the warp and weft tensile strengths of dry flocked fabric due to the high wet properties of cotton yarn. Weft tensile elongation of the flocked fabric is generally higher than warp tensile elongation due to the higher crimp ratio of the flocked fabric in the weft direction. Warp and weft tearing strengths of wet form substrate with adhesive and flocked fabric are higher than those of dry forms of substrate with adhesive and flocked fabric. One of the reasons could be the decrease of inter-yarn frictional forces due to the lubrication effect of the wet form of acrylic adhesive in substrate with adhesive fabric. Generally, tearing strength of flocked fabric is low compared with substrate. It was concluded that the regression model used in this study could be viable and reliable tools and flocked fabric could be considered as an alternative seat cover material to use in automotive industry.     

Mechanical properties of worsted fabrics for emotional garment to the rapier loom characteristics

This study examined the mechanical properties of worsted fabrics woven using various rapier weaving looms. For this purpose, the warp and weft yarn tensions during weaving were measured on the three types of rapier looms, and the fabric mechanical property changes due to the warp and weft tension differences were measured and analyzed according to the fabric position and particular rapier loom using the KES-FB system. The warp tension variation along the loom width direction in P-GTX loom showed the lowest value compared to FAST and THEMA looms. The warp tensions on the central part of the three types of looms were much higher than those on the left and right sides of the looms. The extensibility and bending rigidity of the fabric woven by P-GTX rapier loom showed lower values than those of FAST and THEMA looms, which appears to have originated from the low warp and weft weaving tensions of P-GTX rapier loom. On the other hand, the compressional property and shear modulus showed compromised results due to lateral deformation by compression and constraint deformation of the warp and weft by shear. The friction coefficient of the fabric surface woven by FAST loom showed the lowest value due to the flatter surface by the high warp tension. The mechanical properties of the fabric loaded by a high warp tension on the central part of the loom were also affected by the high weft yarn crimp due to the wider spacing between warp yarns by the higher warp tension during weaving, which makes the surface of the central part of the fabric flatter and smoother than the edge part of the fabric.     

Warp and weft directional tensile properties of multistitched woven fabric E-glass/polyester nano composites

The aim of this study was to understand the warp and weft directional tensile properties of the developed two dimensional (2D) multistitched multilayer E-glass/polyester woven nano composites. It was found that the warp and weft directional specific tensile strength and modulus of unstitched structure were higher than those of the machine stitched and machine stitched/nano structures due to stitching caused filament breakages. When the nano silica material in the unstitched E-glass/polyester composite structure increased, the warp and weft directional specific tensile strength and the modulus of the unstitched/nano structures increased. The failure of warp and weft directional 2D unstitched and unstitched/nano woven E-glass/polyester composite structures had a complete delamination in their cross-sections. But, the failure of warp and weft directional 2D stitched and stitched/nano woven E-glass/polyester composite structures had a local delamination in their cross-sections and the failure was confined at a narrow area. The warp and weft directional specific damaged areas of unstitched structure were higher than those of the stitched and stitched/nano structures. Also, the warp and weft directional specific damaged areas of machine stitched structure were slightly higher than those of the machine stitched/nano structure. It could be concluded that the addition of nano silica to the stitched structures improved to their damage resistance.     

Formability analysis of worsted woven fabrics considering fabric direction

Over years predicting fabric behaviour during garment manufacturing process was considered by researchers in order to reduce manufacturing problems and achieve high quality products. Fabric formability which is affected by bending and tensile behaviour through the application of small loads is a property which can predict fabric performance precisely. However, this property changes regarding fabric direction and is not constant. In this study, fabric formability is examined for worsted woven fabrics in a more detailed way by evaluating this property in various fabric directions. It was concluded that fabric formability could be expressed as a sinusoidal function of sample orientation towards warp direction. Moreover, studying several weave structures with different weft densities reveals that the less the firmness of fabric construction the more the value of fabric formability which indicates the better adaption of fabric to the exerted deformation.     

The effect of fabric balance and fabric cover on surface roughness of polyester fabrics

The effects of fabric balance and fabric cover on surface roughness values of textured polyester woven fabrics with different constructional parameters were investigated. The warp yarn properties (type, count and warp density) were kept constant while the effect of variation in weft yarn density and weave pattern were studied. Measurements were conducted on pre-treated white fabric samples and the results assessed in relation to their constructional properties. A general overview of the results showed that surface roughness values of polyester fabrics affected by fabric balance and fabric cover and the effects were related to fabric thickness, yarn densities, yarn crimp, positioning of yarns in fabric structure. A change in weave pattern from sateen to plain increased the fabric balance and fabric cover, but decreased the surface roughness. Similarly, an increase in weft density increased the fabric balance and fabric cover, but decreased surface roughness. In order to produce fabrics with smooth surface properties yarn density should be increased, yarn float lengths decreased, cover of fabrics increased and fabric balance improved.     

Taguchi analysis of fabric shrinkage

This article reports on the effects of fabric constructional factors such as fabric sett, warp tension, back rest position, and pick insertion rate, on the warp-way and weft-way shrinkages of a three-up-one-down twill woven fabric using a Taguchi design of experiments. It was observed that the fabric shrinkage in the warp direction was mostly affected by the change in the number of picks per inch, followed by warp tension, number of ends per inch, number of picks per minute, and back rest position, respectively. The fabric shrinkage in the weft direction was found to be mostly affected by the change in number of ends per inch, followed by number of picks per inch, back rest position, number of picks per minute, respectively and least affected by warp tension. It was observed that the aforesaid five factors were able to explain 99.02 % and 82.81 % of the total variation of fabric shrinkage in the warp and weft directions, respectively.     

Application of one-quarter fractional and full factorial design to study set mark phenomenon of multifilament polyester fabrics

Set marks are fabric defects in weft direction which are caused by an interruption of the weaving process. In this study, based on one-quarter fractional factorial design, among eight parameters of weaving machine, i.e. horizontal and vertical position of back rest roller, horizontal position of warp stop motion, shed crossing degree, shed crossing point position, warp tension, stoppage position of machine, and stoppage time, four most effective parameters was determined. These parameters were stoppage position of machine, vertical position of back rest roller, shed crossing point, and horizontal position of warp stop motion. Then using full factorial design effectiveness of these parameters was evaluated statistically at 99 % confidence level and effect of them on set mark studied in detail. Statistical evaluations showed that the stoppage position of machine was the most effective parameters on intensity of set mark of multifilament polyester fabric. A specific image capturing device for using on weaving machine based on CCD camera was designed. Image processing technique was used to measure the pickspacing in stop zone objectively. Five picks before and five picks after stoppage was considered as stop zone and the standard deviation of pickspacing was used as a criterion which interpret this defect. Dynamic loading of warp yarns were execute to evaluate the relaxation behavior of polyester multifilament warp yarns.