Laser treatment of the wool fabric for felting shrinkage control

Laser treatment is one of the technologies which are able to eliminate all the adverse effects on the environment caused by chemical treatment commonly used in textile finishing. In this research, we investigated the use of laser treatment for the purpose of wool felting shrinkage control, and compared its effectiveness with that of the traditional chlorination treatment method. The wool fabric was exposed to an industrial laser at two different power levels and two sweep speeds. We found that upon selecting the appropriate treatment parameters, the laser treatment is effective in reducing felting shrinkage of wool fiber by its etching effects on the scales of the wool fiber as shown by the scanning electron micrographs. Too high energy exposure of the wool fiber by laser radiation causes excessive fabric strength loss. We also found that the laser-treated wool has felting shrinkage reduction similar to that treated using the traditional chlorination procedure. The laser technology presents an alternative wool processing method to replace the tradition chlorine treatment method. If this technology can be applied to wool felting-proof finishing on a commercial scale, it will significantly benefit the environment by completely elaminating the harzardous chlorine compounds currently by the industry.     

Influence of pH on hygral expansion,relaxation shrinkage and extensibility of wool fabric

The standard tests for relaxation shrinkage and hygral expansion of wool fabric take no account of pH. It is shown in this work that the pH of the solution in which wool fabric is relaxed as part of the procedure for measuring dimensional properties has a significant influence on the results. At around pH 4.8, which is close to the isoelectric point of wool, the hygral expansion reaches its greatest value and drops at both lower and higher pHs. A similar relationship between pH and extensibility of wool fabric was observed. Values of relaxation shrinkage were found to be dependant on pH. The reasons for the pH dependence of dimensional properties are discussed and these include changes in wool fiber swelling, yarn crimp and polymer relaxation phenomena with changes in pH.     

Application of the real fabric frictional speeds to the fabric sound analysis using water repellent fabrics

This study aims to determine fabric frictional speeds between the arm and the trunk when people walk (1.3 m/s), jog (2.5 m/s) and run (4.5 m/s), and to apply the measured speeds to setting a sound generator for each motion to obtain fabric rustling sounds. By analyzing body motions captured by the Falcon motion analysis system and a camcorder, it was identified that the friction between the arm and trunk occurred within 10° of shoulder angle along the center line of the trunk in the sagittal plane and the maximum frictional speed occurred at the elbow within the shoulder friction range. The averages (SDs) of maximum frictional speed at the elbow were found 0.63 m/s (0.17) at walking, 1.1 m/s (0.25) at jogging, and 1.98 m/s (0.35) at running. The frictional sounds of three coated nylon fabrics were obtained using these predetermined speeds. We calculated sound characteristics such as the sound pressure levels (SPL) and Zwicker’s psychoacoustic parameter using 1/3 octave band analysis. The SPL values ranged from 74.2 dB at running to 79.0 dB at jogging, which was about the same noise level as in the busy street. The values of loudness (Z) at walking and jogging were higher than that at running, but the fluctuation strength (Z) increased in the order of walking, jogging, and running.     

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.     

Novel measurement for multidirectional fabric wrinkling using wavelet analysis

Measuring and characterizing fabric wrinkling objectively and accurately is of vital importance because wrinkling behavior is one of the most important factors to determine visual aesthetic of fabrics and clothes. In this paper, a novel method for multidirectional fabric wrinkling measurement is presented. 12 fabrics with different fiber contents and weave structures are prepared and wrinkled by the new method. GLCM variables and standard deviation of wavelet decomposition coefficients are used to characterize fabric wrinkling. Results show that WRA (wrinkle recovery angle) does not have significant linear correlation with the GLCM variables (energy, entropy, contrast and correlation). The wavelet coefficient standard deviation at level 6 has the highest correlation with average WRA. The equations between average WRA and standard deviations can be used to predicate average WRA of a fabric conveniently, avoiding the time-consuming and tedious testing of WRA in each direction.     

Analysis of woven fabric structure using image analysis and artificial intelligence

An integrated hardware and software system has been developed that can automate the analysis process of various woven fabric structures. Although the analysis of woven structure is one of the most important steps in the fabric design and quality control process, it has been dependent only on human skills with primitive devices. In this study, a dedicated hardware system has been developed to obtain an ultra-high resolution fabric images. Then a series of image analysis technique was applied to locate the intersecting regions of warps and wefts on those images. Finally, an artificial neural network was formed to determine the woven structure of fabric based on the two shape parameters extracted from those regions.     

Measurement of fuzz fibers on fabric surface using image analysis methods

Fuzz on the fabrics, which is the fibers protruded from the fabric surface, is very important in view of appearance quality, since it causes unpleasant appearance on the fabrics and also leads to pilling which makes fabric appearance and softness worse. However, fuzz on fabric surface is measured mostly by subjective methods (human vision) rather than objective methods. Thus, in this study, objective method using image analysis techniques has been developed for the measurement of fuzz on fabric surface. Fuzz on the fabric has also been ranked and rated by experts in order to see the reliability of the results obtained from the fuzz measurement. It was observed that correlation coefficient (r) between rating value and objective measurement value was 0.9 and this correlation coefficient value confirmed the reliability of this method.     

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.     

Applying image analysis to automatic inspection of fabric density for woven fabrics

The gray line-profile method is introduced to find fabric density. Some patterned fabrics like stripe design as well as solid fabrics of basic weave structures are used to verify the efficiency and accuracy of the method. The approach is compared with Fourier transform method. Although the gray line-profile method is concise, it shows good results in both solid and patterned fabrics. In addition, it does not require a pre-processing or filtering technique in space or frequency domain to enhance the image suitable for the analysis. However, the approach is slightly influenced by the filter size for finding the local minimums of profile graph.     

Mechanical analysis of geocomposites consisting of multi-axial warp knitted fabric and nonwoven mat

An eco-friendly shore protection system for preventing the erosion of shore surfaces has been developed using water permeable geocomposites that allow grass to take root in them. The geocomposites require enough stiffness to resist the flow of the water in the stream and good permeability of the flowing water. In this study, a geocomposite is designed using multi-axial warp knitted fabric (MAWKF) and nonwoven mats to ensure both the mechanical stiffness and water absorption. Firstly, a stress analysis is performed for a shore protection system to calculate stresses which are imposed onto geocomposites. To test geocomposites?? capacity to withstand the stress, the geometrical modeling of a MAWKF is carried out and the mechanical behavior of its unit-cell is analyzed using finite element method. Comparing the predicted results with experiments, the validity of the current modeling is demonstrated. Finally the adaptability of the geocomposite is evaluated using the calculated deformation.     

Objective measurement of water repellency of fabric using image analysis (I)

A methodology for the objective evaluation of water repellency is studied using image analysis of the sprayed pattern on woven fabrics according to a standard spray test (AATCC Test Method 22-2001). The wet area ratio obtained from the spray standard test ranking is found to be exponentially related with its water repellency rating. Mean filtering is used to remove the effect of weave texture and the transmitted light through interyarn spaces. The ring frame of the instrument and wet region are recognized using Otsu thresholding technique. And Hough transform and outline operation are used to obtain the size and position of the ring frame. The objective assessment of the water repellency using image processing can reduce unnecessary confusion in the subjective determination of the water repellency.     

Intrinsic differences of sensory analysis from instrumental evaluation on fabric softness by lateral compression

All kinds of instrumental testing methods have been attempted to substitute for sensory analysis of fabric softness, however, the prediction performance is poor. This alone necessitates a deep investigation and understanding of the difference between sensory analysis and instrumental testing under the comparable constrained conditions. By establishing an equivalent biomechanical model to the handling manner in which human fingers sense lateral compression properties of fabric, the mechanistic principle of sensory evaluation on fabric softness property is explored and compared with instrumental testing principle by two proposed indexes, namely the mechanical sensitivity of touch receptors and the sensory sensitivity of human tactile system. The results show that the mechanical sensitivity of human touch receptors leads to the intrinsic difference of sensory analysis from instrumental test on fabric softness by lateral compression. The mechanical sensitivity monotonously changes with the scaling coefficients and the stiffness coefficients of quasi-static and nonlinear compression deformation characterizing both fabric and human skin. The sensory sensitivity depends on both the mechanical sensitivity and the ability of human central system to interpret the information from the peripheral nervous system. The conclusion is that the two-level sensitivity leads to the intrinsic difference between sensory analysis and instrumental evaluation on fabric softness by lateral compression.     

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.     

Correlation with itchy feeling of fabric handling change by physicochemical processing of woolen fabric

The purpose of this research is in solution of two important subjects mutually related; (1) creation of fabrics of various handlings by finish processing and (2) mechanism of generation of itchy feeling acting as the hindrance of a comfortable clothing life and establishment of its objective evaluation method. For the purpose of solution of these two subjects, the same fabrics were used and they were changed by 18 kinds of different physicochemical procedures, which come out 18 levels of fabric handlings ranging from very soft to very stiff. As for handlings of 18 kinds of fabrics, the items of Hand Value were calculated based on all of KES basic properties in terms of KES procedures. Solution of these subjects is also connected with a high level of fabric finishing technology. On the other hand, one of the authors is an expert in fabric finish processing, and has been sure of itchy feeling of fabrics being closely connected with the hardness of fabrics from many years of experience. The degrees of itchy feeling for 18 kinds of fabric were judged by 50 evaluators of different ages and occupations, in terms of five ranks of evaluation method beforehand. As a result, itchy feeling had a high correlation with shear properties and Koshi, and had a negative high correlation with Numeri. It was confirmed that that itchy feeling could be evaluated by objective data of KES properties in terms of KES procedure.     

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.     

High performance fibers production process using Taguchi experimental design

In this research, results of an experimental interaction effect of operating parameters on tensile strength carbon fibers from a commercial PAN-based precursor are investigated. Ten parameters at two and four levels (L₃₂=2¹×4⁹) were investigated: stabilization temperature at first stage (STFIS), stabilization duration time at first stage (SDTFIS), stabilization temperature at second stage (STSS), stabilization duration time at second stage (SDTSS), stabilization temperature at third stage (STTS), stabilization duration time at third stage (SDTTS), stabilization temperature at fourth stage (STFOS), stabilization duration time at fourth stage (SDTFOS), carbonization temperature (CT), and carbonization duration time (CDT). In this study, Taguchi method was used initially to plan a minimum number of experiments. Statistical analysis, analysis of variance (ANOVA), was also employed to determine the relationship between experimental conditions and yield levels. ANOVA was applied to calculate sum of square, variance, ratio of factor variance to error variance and contribution percentage of each factor on response. The results show that increasing all of parameters improves tensile strength performance. The optimum levels of influential factors, determined for tensile strength are STFIS 200 °C, SDTFIS 120 min, STSS 225 °C, SDTSS 120 min, STTS 240 °C, SDTTS 120 min, STFOS 260 °C, SDTFOS 60 min, CT 1400 °C and CDT 10 min. The results showed that CT and ODTFIS are the most and the less effective factors on response, respectively.     

The correlation analysis between the appearance-related performances and the mechanical properties on lyocell-interlining bonded fabric

Lyocell is drawing attention as a new material, environmentally friendly fiber. Precedent researches on lyocell are mostly on structure, characteristics, physical properties, and dyeability. There are few researches on interlining for lyocell clothes production. This study analyzes the correlation between the appearance-related performances of lyocell-interlining bonded fabric and the mechanical properties of fusible interlining, lyocell face fabric, and lyocell-interlining bonded fabric. The stiffness of lyocell-interlining bonded fabric correlates with LT, WT, G, 2HG, 2HG5, B, 2HB, WC, and RC of fusible interlining; LT, EMT, G, 2HG, 2HB, RC, and T of lyocell face fabric; LT, WT, G, 2HG, 2HG5, B, 2HB, and T of lyocell-interlining bonded fabric. The drapability of lyocell-interlining bonded fabric correlates with LT, WT, G, 2HG, 2HG5, B, 2HG, WC, and RC of fusible interlining; LT, EMT, G, 2HG, 2HG5 and RC of lyocell face fabric; LT, EMT, G, 2HG, 2HG5, B, 2HB, LC, RC, and T of lyocell-interlining bonded fabric. The crease recovery of lyocell-interlining bonded fabric correlates with RT, T, W, WT, G, and 2HG of fusible interlining; LC, W, LT, EMT, G, 2HG, and 2HG5 of lyocell face fabric; WC, T, LT, G, 2HG, and 2HG5 of lyocell-interlining bonded fabric.     

Development of an objective fabric pilling evaluation method. I. Characterization of pilling using image analysis

An objective evaluation method for woven fabric pilling has been developed using image processing and statistical analysis. Five ASTM photographic standard images were analyzed to determine a characterization method for fabric pilling. Images were filtered by various image analysis techniques such as fast Fourier transformation (FFT) and fast wavelet transformation (FWT). Three parameters including the number of pills, the total pixel area of pilling, and the sum of the gray values of pill images have been defined and extracted automatically from the images. Finally, the relationship between pilling grade and those parameters has been established by a series of statistical analyses.     

Evaluation of anti-stabbing performance of fabric layers woven with various hybrid yarns under different fabric conditions

Various types of special fibers are used for human body protection, mostly in the form of fiber-reinforced composites. These composites are made of special fibers and matrix resin; however, they are often not comfortable for the wearer due to the lack of flexibility and air permeability. This study focuses on an evaluation of human body protective performance against stabbing for various special fibers such as aramid, basalt, and steel fibers, being utilized in cotton hybrid forms. These hybrid forms are designed to improve wearer comfort, while maintaining adequate anti-stab resistance. Specimens prepared with various fabric densities are tested in terms of anti-stabbing performance, according to the NIJ standard. In addition, we investigate the influence of factors such as fiber type, the number of fabric layers, fabric weight, and fabric density on anti-stabbing performance. Results show that the penetration depth of the impactor, which punctures and protrudes through the specimens, decreases with the number of layers, the thickness, and the mass of the armor sample; however, these factors have different relationships according to the material type. Consequently an objective evaluation of anti-stabbing performance is needed. We suggest an anti-stabbing index that can be applied as a criterion to evaluate the antistabbing performance of various specimens woven with special fibers under different fabric conditions. Using the new index, anti-stabbing performances of various specimens can be compared and raw material and fabric conditions that offer the most efficient anti-stabbing performance can be selected.