Properties of stick-slip stage of yarn pull-out in para-aramid woven fabric

The aim of this study was to understand stick-slip properties of para-aramid woven fabrics. For this reason, pullout test was conducted on para-aramid Kevlar®29 and Kevlar®129 woven fabrics. The stick-slip and accumulative retraction force regions were defined based on the force-displacement curve. It was found that the stick-slip force and accumulative retraction force depended on fabric density and the number of pulled ends in the fabric. Stick-slip force in the multiple yarn pull-out test was higher than those of the single yarn pull-out test. Stick-slip force in single and multiple yarn pull-out tests in the dense K29 fabric were higher than those of the loose K129 fabric. In addition, long fabric samples showed high stick-slip force compared to that of the short fabric samples. On the other hand, the amount of stick-slip force was related to the number of interlacement points in the fabric whereas the amount of accumulative retraction force was related to fabric structural response.     

Pull-out properties of polyester woven fabrics: Effects of softening agent and interlacement on single and multiple yarn pull-out forces and analysis by statistical model

The aim of this study was to understand the effects of softening treatment on pull-out properties of plain, ribs and satin fabrics. Polyester woven fabrics were used to conduct the pull-out tests. Data generated from these tests included pullout force, crimp extension and fabric displacement. A developed yarn pull-out fixture was used to perform single and multiple pull-out tests on treated and untreated polyester fabrics. Yarn pull-out forces depend on fabric treatments, fabric density, fabric weave, and the number of pulled ends in the fabric. The results of regression model showed that multiple and single yarn pull-out forces of treated fabrics were lower than those of untreated fabrics. The multiple yarn pull-out force was higher than that of the single yarn pull-out force, and that dense fabric had a high pull-out force. Treated and untreated plain fabrics had high single and multiple pull-out forces compared to those of treated and untreated ribs and satin fabrics. Yarn crimp extension depends on directional crimp ratios in the fabric and the number of pulled yarn ends. High directional crimp ratio fabric showed high directional yarn crimp extension. Fabric displacement depends on the number of pulled yarn ends and also fabric treatments. Fabric displacement in multiple pull-out tests showed high fabric displacement compared to that of single pull-out tests. On the other hand, the regression model could be used in this study as a viable and reliable tool.     

Effects of sample dimensions on pull-out properties of woven fabric structures

The aim of this study was to understand the effects of fabric sample dimensions on pull-out properties of fabric weaves. Polyester woven fabrics were used to conduct the pull-out tests. A yarn pull-out fixture was developed and data generated from this research. Yarn pull-out forces depend on sample dimensions, fabric density, fabric weave, and number of pulled ends in the fabric. Results showed that multiple and single yarn pull-out forces of long samples were higher than those of short samples, and the multiple yarn pull-out force was higher than that of the single yarn pull-out force, and dense fabric has high pull-out force. Plain fabric weave showed high single and multiple pull-out forces compared to ribs and satin fabric weaves. The regression model could be used in this study as a viable and reliable tool. This research could be valuable for development of multifunctional fabrics in technical textile applications.     

Analysis and in-plane shear characterization of polyester plain fabric by yarn pull-out method

The aim of this study was to determine the in-plane shear properties of polyester fabric by the pull-out method and analytical relations were developed to calculate the shearing properties. After the yarn in the fabric was pulled from the top ravel region before the start of the crimp extension stage, it was found that fabric shear strength and rigidity increased when the number of pulled ends increased. In addition, when the fabric width and length increased, fabric shear strength and rigidity increased. On the other hand, the shear strength and rigidity values in untreated fabric were high compared to that of treated fabric due to the fabric treatments by softening agent. It was observed that fabric sample dimensions and the number of pull-out ends as well as the fabric treatments influenced fabric shear strength and rigidity. Also, the shear jamming angles were found to be based on the number of pulled ends. Fabric local shearing properties could be identified by pulling the yarn ends in various regions of the fabric. This could be important for the handling of the fabric during formation. The results generated from this study showed that polyester fabric shear could be measured by the yarn pull-out test.     

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.     

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.     

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.     

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.     

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.     

A new approach for numerical identification of bending behavior of plain woven fabric

There is a variety of approaches for investigating bending behavior of woven fabrics. Some of them are based on fabric deformation with one edge fixed; the others are based on measurement of force, moment or energy producing bending deformation. In all methods, bending properties is acquired after testing prepared fabric samples. Therefore, in this work an attempt is made by a mechanical model and a novel calculation technique to determine bending characteristics of the plain woven fabrics before sample production. Theoretical data including bending length, bending rigidity and bending modulus were directly determined for supposed fabric samples with a given yarn count and yarn density using Peirce’s structural model for plain woven fabric and a especial code written in Maple12. Besides, fabric samples with the defined characteristics were woven on a Sulzer-Ruti weaving machine. Then, these fabrics were tested for bending behavior using Shirley bending tester. Comparison showed good agreement between predicted and measured bending characteristics of the fabrics. However, theoretical bending rigidities of the samples were more than experimental values.     

麻盖涤吸湿快干针织面料性能及整理工艺研究

以纯苎麻纱和细旦涤纶为原料编织麻盖涤双面针织物;用亲水性硅油、水性聚氨酯、纤维素酶等进行吸湿快干、柔软以及消除刺痒感的整理。结果表明:麻盖涤针织面料的吸湿快干性能比棉盖涤好,通过应用合适的整理剂和整理工艺能有效地解决麻盖涤针织物手感和刺痒感问题。本文还对纯苎麻纱针织织造中断纱爆孔问题提出了解决的措施。     

麻盖涤吸湿快干针织面料性能及整理工艺研究

以纯苎麻纱和细旦涤纶为原料编织麻盖涤双面针织物；用亲水性硅油、水性聚氨酯、纤维紊酶等进行吸湿快干、柔软以及消除刺痒感的整理。结果表明：麻盖涤针织面料的吸湿快干性能比棉盖涤好，通过应用合适的整理剂和整理工艺能有效地解决麻盖涤针织物手感和刺痒感问题。本文还对纯苎麻纱针织织造中断纱爆孔问题提出了解决的措施。     

Electromagnetic interference shielding effectiveness of SS/PET hybrid yarn incorporated woven fabrics

A detailed study of electromagnetic shielding effectiveness (EMSE) of woven fabrics made of polyester and stainless steel/polyester blended conductive yarn was presented in this research work. Fabrics with different structures were analyzed and their shielding behavior was reported under different frequencies. Shielding efficiency of fabric was analyzed by vector network analyzer in the frequency range of 300 kHz to 1.5 GHz using coaxial transmission line holder. The effects of different fabric parameters such as weft density, proportion of conductive weft yarn, proportion of stainless steel content, grid openness, weave pattern and number of fabric layers on EMSE of fabrics were studied. The EMSE of fabric was found to be increased with increase in proportion of conductive yarn in the weft way. With increase in overall stainless-steel content in the fabric, the EMSE of fabric was increased. As such weave is considered, it did not have significant effect on EMSE of fabrics. But fabric with lower openness and aperture ratio showed better conducting network, hence better shielding. With increase in number of layers of fabric and ply yarns, EMSE of fabric was increased.     

Determination of para-aramid single fabric shear by yarn pull-out and analysis by statistical model

The aim of this study was to determine the para-aramid fabric shear by the pull-out method. The fabric sample dimensions and the number of pull-out ends were identified as important parameters. Fabric shear depended on fabric density. Fabric shear strength increased when the number of pulled ends increased. When the fabric length increased, fabric shear strength generally increased. The number of pulled ends and the fabric sample dimensions influenced the fabric shear rigidity. Shear jamming angles were found based on the number of pulled ends. The results showed that para-aramid fabric shear could be measured by yarn pull-out test.     

Handle,fit and pressure comfort of silk/hybrid yarn woven stretch fabrics

Hybrid yarn was produced by twisting silk with nylon covered lycra yarn. Silk of 20 D in warp and hybrid yarn in weft was woven to develop lustrous woven stretch fabrics for sari blouse. Silk and hybrid yarn fabrics were produced in three different weaves namely plain, crepe and sateen. An in-depth study was carried out to understand the effect of weave on thermal comfort; low stress mechanical properties, total hand value and stretch properties. Nine blouses (3 samples× 3 figures) were constructed from three different woven stretch materials for fit assessment and objective pressure comfort test. The effect of fabric weave, low stress mechanical properties, total hand value and stretch properties on fit and pressure comfort of silk/hybrid yarn stretch fabrics were analyzed. Sateen weave silk/hybrid yarn stretch fabric shows higher total hand value, stretch properties and better thermal comfort properties. Sateen and crepe weave stretch fabrics provided good fit. Sateen weave fabric exerted lower clothing pressure value in the range of 3-12 mmHg at all body locations in standing position and in different postures.     

New production method for a plain weave figured fabric

A new production method for figured fabric has been developed. The figured fabric generated in this study is a plain weave piled fabric and it shows the same figure on both sides unlike those fabrics woven on dobby or jacquard looms. It is woven by a specialty yarn called the chenille yarn which is obtained by separating each warp of a base fabric woven in leno structure. The base fabric is woven by inserting different colored weft each time in a certain sequence arranged according to the target figure image. A CAD software and a computerized controller have been developed to control all the motions of a conventional rapier loom and to handle the numerous weft insertion schedule efficiently.     

Study on heat and moisture vapour transmission characteristics through multilayered fabric ensembles

A detailed study on the heat and moisture vapour transmission characteristics of different types of single and multi-layered fabric ensemble by using sweating guarded hot plate (SGHP) has been reported in the present paper. A comparison has been made on thermal and moisture vapour transmission properties of five different insulative fabrics, namely, knitted-raised fabric, needle punched nonwoven, through air bonded nonwoven, spunbonded-through air bonded sandwich nonwoven and warp knitted spacer fabric and three different coated fabrics, namely, plain woven rubber coated, plain woven polyester polymer coated and plain woven polytetrafluoroethylene (PTFE) coated fabric, used for thermal insulation purpose. ANOVA has been conducted to analyse the significance of type of insulative and coated fabrics used. Sandwich nonwoven fabric which has higher thickness and porosity shows higher thermal resistance followed by through air bonded fabric, raised fabric, needle punched fabric and spacer fabric. Spacer fabric shows lesser evaporative resistance due to its lesser thickness and larger aperture size, which increases the diffusion of moisture vapour. Needle punched fabric shows slightly higher evaporative resistance than spacer fabric, followed by raised fabric, through air bonded fabric and sandwich nonwoven fabric. Permeability index of different multilayered fabric ensembles are also compared.     

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.     

The effects of yarn number and liquid ammonia treatment on the physical properties of hemp woven fabrics

The effects of yarn number and liquid ammonia (L/A) treatment on the physical properties of woven fabrics prepared with pure hemp spun yarns were investigated. As a result of L/A treatment, the crystal structure of hemp fiber was changed from cellulose I to the mixtures of cellulose III and cellulose I and its crystallinity was slightly decreased by 13 %. The crease recovery of hemp fabric treated with L/A was improved upto 78 %. The washing shrinkage of hemp fabric treated with L/A decreased significantly to less than 0.4 %, while the washing shrinkage of hemp fabric prepared with the fined yarn was superior to that of hemp fabric prepared with the coarsed yarn. Especially, the wicking speed and drying ratio of hemp fabrics treated with L/A were higher than those of the untreated as yarn number increased. However, it was found that there is no significant effect on the UV protection of the L/A treated hemp fabrics.     

Analysis and off-axis tensile characterization of air-entangled textured polyester woven fabrics depending on unit cell interlacing frequency

The aim of this study is to analyze and determine the off-axis tensile properties of air-entangled textured polyester fabrics based on unit cell interlacing frequency. For this purpose, continuous filament polyester air-entangled textured yarn was used to produce plain, ribs and satin woven fabrics. The fabrics were cut from the warp direction (0°) to weft direction (90°) at every 15° increment, and tensile tests were applied to those of the off-axis samples. The strength and elongation results were introduced to the statistical model developed, and regression analyses were carried out. Hence, the effects of off-axis loading and interlacement on the directional tensile properties of the fabric were investigated. The regression model showed that off-axis loading influences fabric tensile strength. On the other hand, interlacement frequency is the most important factor for fabric tensile elongation. The results from the regression model were compared with the measured values. This study confirmed that the method used in this study as can be a viable and reliable tool. Future research will concentrate on multiaxially directional fabric and the probability that it will result in homogeneous in-plane fabric properties.