Mechanical properties and tactile sensation of naturally colored organic cotton fabrics

This study was carried out to investigate mechanical properties of naturally colored organic cotton (NaCOC) fabrics, to evaluate tactile sensory perceptions, and finally to identify the related mechanical parameters with the sensory perceptions. Two species, coyote-brown and green NaCOC fiber, commercially available, were selected and woven into plain and twill fabrics. Seventeen mechanical properties were measured by KES-FB system. Then, primary hand value (PHV) and total hand value (THV) were calculated by KN-203-LDY and KN-302-SUMMER, respectively. For sensory perception evaluation, 30 participants answered the questionnaire consisted of nine different bipolar adjectives dealing with tactile sensation using the semantic differential scale (SDS). As the result of mechanical properties, there were meaningful differences in shear, surface, compression properties, thickness, and weight of 4 NaCOC fabrics. For hand value, a coyotebrown twill fabric was evaluated as the most appropriate for lady’s summer dress applications. In sensory perception evaluation, meaningful differences of sensory perception were shown among 4 specimens except ‘fineness’ and ‘wetness’ perceptions. Prediction models for sensory perceptions of NaCOC fabrics were extracted by regression analysis in ‘softness’, ‘fineness’, ‘warmth’, ‘pliability’, ‘limpness’, ‘thinness’ and ‘wetness’ perceptions.     

Application of acacia natural dyes on cotton by pad dyeing

Coloration of textiles, traditionally achieved using natural dyes, commonly employs synthetic dyes at the industrial level. A revival of commercial interest in natural dyes has opened several research avenues. This paper investigates the application by padding of cotton fabric with 10 g/l of two natural dyes derived from the Acacia plant family. Three mordanting techniques were studied; of which post-mordanting produced the most even shade. Among the two mordants investigated, the use of copper sulfate resulted in a level beige shade at 15 g/l concentration while ferrous sulfate performed best at 5 g/l yielding a yellow-grey shade. An optimum process-sequence for the copper sulfate mordant was “pad (dye)→dry→steam followed by pad (mordant)→steam→dry”, and for ferrous sulfte it was “pad (dye)→steam→dry followed by pad (mordant)→steam→dry”. Typically a change in mordant resulted in a different shade with the same dye. The study concluded that padding is a readily adaptable process for the dyeing of cotton using natural dyes and acceptable fastness in shades can be obtained.     

Predicting properties of single jersey fabrics using regression and artificial neural network models

In our previous works, we had predicted cotton ring yarn properties from the fiber properties successfully by regression and ANN models. In this study both regression and artificial neural network has been applied for the prediction of the bursting strength and air permeability of single jersey knitted fabrics. Fiber properties measured by HVI instrument and yarn properties were selected as independent variables together with wales’ and courses’ number per square centimeter. Firstly conventional ring yarns were produced from six different types of cotton in four different yarn counts (Ne 20, Ne 25, Ne 30, and Ne 35) and three different twist multipliers (α _e 3.8, α _e 4.2, and α _e 4.6). All the yarns were knitted by laboratory circular knitting machine. Regression and ANN models were developed to predict the fabric properties. It was found that all models can be used to predict the single jersey fabric properties successfully. However, ANN models exhibit higher predictive power than the regression models.     

Assessment of color strength and color difference values of polyester fabrics containing continuous weft yarns after abrasion

This paper assesses the color difference and color strength values (K/S) obtained for eight disperse-dyed polyester fabric samples with different fabric construction parameters (weft yarn type, weft yarn count, weft density and fabric weave) after four sets of abrasion cycles. Warp yarn type and count, warp density, and warp yarn twist are the same for all fabrics. Fabric samples are dyed in a commercial red disperse dye (C.I. Disperse Red 74:1) and four different abrasion cycles (2500, 5000, 7500, 10000) are used. TheK/S values of the abraided fabrics and color difference values between the control fabric (dyed but not abraided) and abraded fabrics are calculated. The main differences in theK/S and color difference values are observed between 0–2500 abrasion cycles. The high tenacity of the polyester fibers and continuous polyester yarns causes some fuzz but no pilling formation on the fabric surface that lead to increasedK/S values and color differences. Fiber dullness, yarn thickness, yarn density and fabric weave are concluded to have different effects on the appearance after abrasion.     

Drape simulation of three-dimensional virtual garment enabling fabric properties

This study analyzes how the silhouette of virtual garments applied to virtual avatars is altered according to various virtual fabric properties. This study measures the properties of real fabrics that include a charmeuse (#F1) and gabardine (#F2) using the Fabric Analysis by Simple Testing system; in addition, the material properties of different real fabrics were applied to that of the virtual fabric. It then evaluates the drape stiffness and silhouette of the virtual garments according to the different fabrics. This study also compared the virtual garment silhouette of sample fabric #F1-S that changed only the stretch property of the sample fabric #F1 with the virtual garment silhouette of sample fabric #F1. The results show that the fabric properties including bend, thickness, weight, stretch, shear values affect the drape stiffness, silhouette, and fit of the virtual garment simulated on virtual avatars and may be used for the realistic virtual garment technology.     

A study of comfort performance in cotton and polyester blended fabrics. I. Vertical wicking behavior

Vertical wicking model was developed based on Darcy’s law. In the model, permeability coefficient, capillary pressure and fabric thickness were used as the key parameters to describe wicking behavior. For the simulation and test, fiber type and fabric structure were chosen as variables. In a highly porous knit fabric, gravitational effect during the wicking process was significant. The higher the capillary pressure was, the higher was the wicking rise. Surface wetting tension, i.e., the specific fluid affinity of material, was newly defined to characterize different capillary pressures in various types of fabric structures. The model, the methodology and the results could provide an insight into fabric design to produce fabric with an optimum wicking performance.     

Calculation of bed load based on the measured data of suspended load

This paper proposes a method for establishing both the velocity profile and concentration profile for suspended sediment based on measured data consisting of average velocity and average suspended sediment concentration in the river and the irrigation channel. In addition, a numerical model for computing suspended load and bed load was also developed for computing bed load transport rate when measurable load is available. In this study, bed loads for published laboratory and field sediment data were computed using the presently developed numerical model based on four different bed layer thicknesses. The computed bed loads were found to be in reasonable agreement with the values from Einstein’s bed load function when the thickness of the bed layer was taken at 10θd or 0.05D. The numerical model developed in this study may be used to evaluate the validities of other bed load formulas.     

Multifunctional colored polyester fabric treated with dopamine hydrochloride at room temperature: higher tensile,hydrophilicity and anti-bacterial properties along with aminolysis

In this work, dopamine hydrochloride, an environmental friendly compound, was applied on polyester fabric through conventional simple impregnation method in alkaline solution (pH=8.5) at room temperature. In situ spontaneous oxidative polymerization of dopamine form polydopamine (PDA) along with aminolysis of polyester fabric surface. Also, a range of colored polyester fabric were successfully achieved by formation of polydopamine adhesive coating layer at different concentration of dopamine hydrochloride (0.001-4 g/l). Fourier transform infrared spectroscopy and field emission scanning electron microscopy showed deposition of polydopmaine on the polyester fabric surface. The modified colored polyester fabric showed reasonable durability against washing, rubbing and light. The treated polyester fabric with 2 g/l dopamine hydrochloride as optimum concentration indicated not only lower spreading time for water droplet and electrical resistance with higher tensile strength but also very good bactericidal activity against Staphylococcus aureus and Escherichia coli.     

Optimization of enzymatic hydrolysis of waste cotton fibers for nanoparticles production using response surface methodology

A Box-Behnken design (BBD) was used for optimization of enzymatic hydrolysis of waste cotton fibers in order to obtain finest cellulose particles. The effect of three factors including hydrolysis time (h), substrate concentration (g/l) and enzyme loading (%) were investigated. The median size of the hydrolyzed particles was defined as the response function of the design. Results of BBD were subjected to analysis of variance (ANOVA) and a quadratic polynomial equation was developed for predicting the particle size. According to the fitted model, the optimal conditions i.e. hydrolysis time, substrate concentration and enzyme loading were suggested as 175 h, 5 g/l and 2.3 %, respectively. The suspension prepared under optimum conditions was subjected to ultrasonic treatment, and the resulted stable suspension of cellulose nanoparticles was characterized. It was found that these nanoparticles are spherical and most of them are in the range of 40–90 nm. The enzymatic and ultrasonic treatments caused an increase in the crystallinity and a decrease in the degree of polymerization of cotton.     

The psycho-physiological response of polyethylene terephthalate irradiated by ultra-violet: Subjective fabric hand and wear comfort

The purpose of this study was to compare the subjective fabric hand evaluation and wear comfort of PET treated by Ultraviolet and to evaluate the subjective results from the investigation of microclimate temperature. The subjective hand evaluation was performed by 20 subjects (age: 20–25) with 5-point scale questionnaires to investigate the change of PET knit fabrics treated for different times, specifically, 0, 30 and 90 minutes. The questionnaires were composite with 8 questions; roughness, smoothness, wetness, stiffness, coolness, touch, preference, and comfort. In order to evaluate sensations of wear comfort, we made garments with UV treated fabric and five female students were tested. They walked at the speed of 6.7 km/hr for 15 minutes in an environment, which was controlled at 29°C, 75±5 % RH. Before and after exercising, the microclimate under clothing and subjective wear comfort was measured. The results of subjective evaluation of fabric hand were that untreated and treated for 30 minutes PET were recognized as similar and have a good evaluation on comfort, preference, and touch. According to the result of wear comfort, clothing treated by UV for 90 minutes had the lowest value on the thermal and humidity sensations. In addition, the value of tactile and comfort sensation was the highest on the clothing treated by UV for 90 minutes. In the case of objective evaluation, PET treated for 90 minutes was the lowest on microclimate humidity. PET irradiated by UV for 90 minutes was more ‘cool’ in thermal sensation and more ‘dry’ in wet sensation. Accordingly, it was consistent with the result of subjective wear comfort.     

Psychoacoustic characteristics of fibers

In order to investigate psychoacoustic characteristics of fibers, and to compare them with sound physical parameters, each sound of 25 different fabrics consisted of a single fiber such as wool, cotton, silk, polyester, and nylon was recorded. Sounds of specimens were transformed into critical band diagram and psychoacoustic characteristics including loudness and sharpness for each sound were calculated based on Zwicker’s models. Physical parameters such as the level pressure of total sound (LPT), level ranges (ΔL), frequency differences (Δf), AR coefficients (ARC, ARF, ARE) were obtained in fast fourier transform (FFT) spectrum. Nylon taffeta showed higher values for loudness than 2.5 sone corresponding to human low conversation, while most silk fibers generated less louder showing lower values for loudness than 1.0 sone. Wool fibers had higher loudness mean value than that of cotton, while the two fibers didn’t differ in LPT. Loudness showed high positive correlation coefficients with both LPT and ARC. Sharpness values were higher for wool fiber group than other fibers. Sharpness was not concerned with loudness, LPT, and ARC, but the fabrics with higher values for sharpness tended to show higherΔL.     

Effect of selected Egyptian cooking methods on faba bean nutritive value and dietary protein utilization 2: Ability of faba bean products to support hemoglobin response in rats

To evaluate the dietary protein utilization and iron deficiency anemia as affected by the faba bean nutrient intake, a bioassay with rats was carried out with different experimental diets containing four faba bean products (stewed beans ‘Medammis’, deep fried dough ‘Falafel’, boiled germinated beans ‘Nabet Soup’ and poured paste ‘Bissara’) widely consumed in the Middle East. Amino acid composition of all faba bean products was determined and compared to raw beans. Severe heat-processing markedly decreased some essential amino acids, especially phenylalanine, cystine, methionine and tryptophan. Protein scores were 24.6, 19.5, 29.2, 28.2 and 35.6 for raw faba beans, ‘Medammis’, ‘Falafel’, ‘Nabet Soup’ and ‘Bissara’, respectively. ‘Bissara’ possessed the highest nutritional value, since it had the lowest GDR value [Grams consumed of product to cover the daily requirements for adult man in protein (63 g) and in energy (2900 kcal)] for the limiting amino acids (L A A). As indicated by P S/150 values [Satisfaction of the daily requirements of the adult man when 150 g (one can content) are consumed of product] for L A A, i.e. methionine+cystine (lowest P S/150 value), the above-mentioned faba bean products cover about 53, 77, 77 and 97% of the daily requirements of adult man in L A A, respectively. Fecal nitrogen excretion increased and true nitrogen digestibility decreased significantly (p<0.01) with the inclusion of ‘Medammis’ in the diet. ‘Nabet Soup’ exhibited the highest true nitrogen digestibility. In contrast, the biological value of nitrogen was apparently unaffected. Highest blood hemoglobin level was found in rats fed diets containing ‘Bissara’, ‘Falafel’ and ‘Nabet Soup’, whereas the addition of ‘Medammis’ in the diet induced a significant (p<0.05) reduction in blood hemoglobin level of fed rats.     

Optimization of enzymatic treatment of polyester fabrics by lipase from <Emphasis Type="Italic">Porcine Pancreas</Emphasis>

The aim of this study was to provide the optimum condition for improving the hydrophilicity of PET fabrics by lipase treatment. The lipase hydrolytic activity, moisture regain, and wettability of PET fabrics were measured at different pH, temperature, reaction time, and concentration. The hydrolytic activity of lipase was evaluated by the number of carboxylic groups, using the titration method. Each treatment condition was controlled by measuring the hydrolytic activity, moisture regain, and wettability. The lipase treatment condition was controlled at pH 7.5, temperature 40 °C, treatment time 90 min, and concentration 6.25 g/l. Lipase treatment was an effective method to improve the moisture regain and wettability of PET fabrics because lipase hydrolysis formed hydrophilic groups on the surface of PET fabrics. The surface of the lipase-treated PET fabrics showed cracks and voids, largely responsible for the increase in the PET’s water-related properties. The nitrogen contents of the lipase-treated PET fabrics were measured at only 0.072 %. Thus, the improvement of the surface wettability of the lipase-treated PET surface was associated with the hydrolytic action of lipase rather than with protein absorption.     

Effect of repeated laundering and Dry-cleaning on the thermo-physiological comfort properties of aramid fabrics

This research investigated the effect of repeated laundering and dry-cleaning on the physical and thermophysiological comfort properties such as air permeability, water vapour resistance and thermal resistance of fabrics made of meta-aramid (Nomex®) fibre. Two different types of fabric were selected for the study and subjected to repeated laundering and dry-cleaning (1, 5 and 10 cycles), which is commercially used for the care and maintenance of these fabrics. The fabric thickness, areal density, thermal resistance and water vapour resistance values increased with the number of laundering cycles, whereas the air permeability decreased due to the fabric shrinkage and swelling. On the other hand, the thickness and air permeability of the dry-cleaned fabric samples increased with the number of cycles; while the water vapour resistance and thermal resistance decreased. The scanning electron microscopy images showed the structural changes as indicated by the longitudinal fibrillation in the fabrics subjected to laundering or dry-cleaning.     

Dimensional and physical properties of plain knitted fabrics made from 50/50 bamboo/cotton blended yarns

In this study, the dimensional and some physical properties of plain knitted fabrics made from 50/50 bamboo/cotton blended yarns are investigated. In order to see the differences and similarities, the results are then compared with those for similar fabrics knitted from 50/50 conventional viscose/cotton and 50/50 modal/cotton blended yarns. Each fabric type was produced with three different stitch lengths. After all fabrics were dyed under identical dyeing conditions, they were subjected to dry and full relaxation treatments. For dimensional properties of fabrics, course, wale and stitch densities were measured. Then, by calculating statistically best-fit lines passing both through the experimental points and the origin, dimensional constants i.e. k values were predicted in terms of the fiber types. The result show that each fabric type knitted from bamboo/cotton, viscose/cotton and modal/cotton blended yarns behaves in a similar manner. However, in both dry and fully relaxed states, the modal/cotton knitted fabrics tend to have slightly higher k values than the bamboo/cotton and viscose/cotton knitted fabrics. For physical properties, fabric weight per unit area, thickness, bursting strength, air permeability and pilling were evaluated. The results show that the weight, thickness and air permeability values are independent of the fiber type. Plain knitted fabrics from modal/cotton blended yarns have the highest bursting strength values. Plain knitted fabrics from bamboo/cotton blended yarns tend to pill less.     

Compression properties of weft knitted fabrics consisting of shrinkable and non-shrinkable acrylic fibers

High-bulk worsted yarns with different shrinkable and non-shrinkable acrylic fibers blend ratios are produced and then single jersey weft knitted fabrics with three different structures and loop lengths are constructed. The physical properties of produced yarns and compression properties of produced fabrics at eight pressure values (50, 100, 200, 500, 1000, 1500 and 2000 g/cm²) were measured using a conventional fabric thickness tester. Then, weft-knitted fabric compression behavior was analyzed using a two parameters model. It is found that at 40% shrinkable fibre blending ratio the maximum yarn bulk, shrinkage, abrasion resistance and minimum yarn strength are obtained. It is also shown that high-bulk acrylic yarn has the highest elongation at 20% shrinkable fibre blend ratio. The statistical regression analysis revealed that the compression behavior of acrylic weft-knitted fabrics is highly closed to two parameter model proposed for woven fabrics. It is also shown that for weft-knitted structure, there is an incompressible layer (V′) which resists against high compression load. Acrylic weft-knitted fabrics with knit-tuck structure exhibit higher compression rigidity and lower softness than the plain and knitmiss structures. In addition, at 20% shrinkable fibre blend ratio, the high-bulk acrylic weft-knitted fabrics are highly compressible.     

Effects of fabric surface energy on human thermophysiological responses during exercise and recovery

The present paper reports a study on influences of fabric surface energy of cotton and polyester garments on clothing microclimates and human thermophysiological responses during intermittent exercise and recovery. Eight healthy males wearing the garments prepared performed exercises and rest according to the following protocol: rest for 30 min, run on treadmill for total 60 min of three sessions with different intensity and duration, and then sit quietly for 30 min for recovery, all at 30 °C and relative humidity of 30 %, while the microclimate humidity (H _mc ) and temperature (T _mc ), the clothing outside surface humidity (H _co ) and temperature (T _co ), the skin temperatures and ear canal temperature (T _{ear_canal} ) were measured. The garments are made of: (a) hydrophilic and hydrophobic cotton knitted fabrics, and (b) hydrophilic and hydrophobic polyester knitted fabrics. During and after exercise, for cotton, hydrophilic garment resulted in significant lowerΔH _mc , ΔH _co , ΔT _mc during recovery, higher , lowerΔT _{ear_canal} andΔT _forehead . For polyester, hydrophilic garment resulted in significantly lowerΔH _co , ΔT _co , higher , higherΔT _forehead during E1, E2 and recovery session but lower during E3. In summary, surface energy of cotton garments had significant influences on human thermophysiological responses during exercise and recovery, and hydrophilic cotton garment was better than hydrophobic one to reduce heat stress. Surface energy of polyester garments had influences of lower significance, and hydrophilic garment appeared better than hydrophobic garment.     

A semi-selective medium for estimating population densities of pectolyticErwinia spp. in soil and in plant material

Summary Stewart’s medium modified by omitting bile salts and adding 1.15×10⁻³ g/l gentian violet and 20 ppm Agral 90 was better than the original medium and as good as a nonselective medium such as nutrient agar for estimating population numbers ofErwinia carotovora var.carotovora andE. carotovora var.atroseptica. Although growth of unwanted organisms on soil dilution plates of the modified Stewart’s medium was slightly more extensive than on those of the complete Stewart’s medium, viable counts ofErwinia were still feasible.     

Changes in a knitted fabric’s surface properties due to enzyme treatments

Enzyme treatment technologies in textile processing have become commonly-applied techniques for the modification of fabric-handle appearance, and other surface and mechanical characteristics of fabrics. Most studies have focused on understanding the impact of enzyme treatments on the fabric preparation, dyeing, and finishing processes of woven fabrics, whilst only limited research has been reported regarding any enzymatic effects on the surface and handproperties of knitted fabrics. The aim of this study was to analyze the effects of two different enzymes Trichoderma reesei whole cellulase, and enriched (EGIII) endoglucanase cellulase, at three different enzyme dosages on 100 % cotton interlock knitted fabric. This was in order to evaluate certain surface properties such as pilling, friction. and geometrical roughness. Furthermore, the compression and tactile properties of knitted fabric were also analyzed. The results show that treatment conditions with enzyme Trichoderma reesei whole cellulase had the more pronounced effect on the surface properties compared to the enriched EGIII enzymes. In general, it can be concluded that both types of enzymes improved the surface properties and hand when compared with the silicone softener-treated reference sample of interlock knitted fabric, as is statistically confirmed by one-way analysis of variance.     

Green composites. II. Environment-friendly, biodegradable composites using ramie fibers and soy protein concentrate (SPC) resin

Fully biodegradable and environment-friendly green composite specimens were made using ramie fibers and soy protein concentrate (SPC) resin. SPC was used as continuous phase resin in green composites. The SPC resin was plasticized with glycerin. Precuring and curing processes for the resin were optimized to obtain required mechanical properties. Unidirectional green composites were prepared by combining 65 % (on weight basis) ramie fibers and SPC resin. The tensile strength and Young’s modulus of these composites were significantly higher compared to those of pure SPC resin. Tensile and flexural properties of the composite in the longitudinal direction were moderate and found to be significantly higher than those of three common wood varieties. In the transverse direction, however, their properties were comparable with those of wood specimens. Scanning electron microscope (SEM) micrographs of the tensile fracture surfaces of the green composite indicated good interfacial bonding between ramie fibers and SPC resin. Theoretical values for tensile strength and Young’s modulus, calculated using simple rule of mixture were higher than the experimentally obtained values. The main reasons for this discrepancy are loss of fiber alignment, voids and fiber compression due to resin shrinking during curing.