Surface modification of polyester fabrics by enzyme treatment

In this study, the effect of enzymatic hydrolysis using lipase and cutinase on poly(ethyleneterephthalate) (PET) fabrics was investigated in an attempt to improve the hydrophilicity of these fabrics. The hydrolytic activity of the enzymes was expressed for variations in pH levels, temperatures, enzyme concentrations, and treatment times. The effects of using a nonionic surfactant were examined by measuring moisture regain and surface wettability. Finally, the fabric characteristics that were affected by enzyme treatment were evaluated by tensile strength and scanning electron microscopy. The optimal treatment conditions for lipase were determined to be a pH of 4.2, a temperature of 50 °C, a lipase concentration of 100 %, and a treatment time of 90 min; those for cutinase were determined to be a pH of 9.0, a temperature of 50 °C, a cutinase concentration of 100 %, and a treatment time of 60 min. At optimal enzymatic treatment conditions, we got the significant results of increase on the moisture regain and the water contact angle (WCA) and water absorbency effectively decreased. Triton X-100 facilitated cutinase hydrolysis on PET fabrics; however, it was ineffective for lipase. With enzymatic treatment, the tensile strength did not decrease.     

Optimization of enzymatic treatment of polyamide fabrics by bromelain

In this study, we investigated the effects of enzymatic hydrolysis on polyamide fabrics by using bromelain as an enzyme. The hydrolytic activity of bromelain was evaluated on the basis of the number of carboxylic groups formed on the surface of the polyamide fabrics, and it was measured using the reactive dye absorbance. In addition, 2,4,6-trinitrobenzenesulfonic acid was added as an indicator to measure the number of amino groups released into the treatment liquid by the changes in color of the liquid. The optimum treatment conditions were bromelain pH of 6.0, treatment time of 120 min, temperature of 50 °C, concentration of 10 % (owf), and L-cysteine concentration of 70 mM. The weight loss in the fabric after treatment with bromelain facilitated by L-cysteine significantly improved; however, the tensile strengths of the polyamide fabrics did not show any differences. Bromelain hydrolysis of the polyamide fabrics thus improved hydrophilicity without damaging the fabrics’ strength.     

Effect of ultrasonic laundering on thermophysiological properties of knitted fabrics

The paper focuses on the application of ultrasonic energy in textile laundering. In recent years, there has been an increasing interest in ultrasonic energy application in textile industry; however, the effect of ultrasonic laundering on the thermophysiological properties of knitted fabrics has not been studied yet. This study was conducted by using polylactic acid (PLA), cotton, polyethylene terephthalate (PET), and poly acrylic (PAC) fibres containing yarns and their blends. Knitted fabrics, single pique, were made from these yarns by using weft knitting machine. The fabrics were washed ten times for 15 and 60 minutes under 40 °C by using conventional and ultrasonic washing methods. The main aim was to determine the effect of washing methods on the thermophysiological properties of the fabrics. It is also aimed to analyse and evaluate the thermophysiological properties of the PLA fabrics. The incorporation of 100 % PLA and cotton/PLA yarns into single pique knitted fabrics has been attempted to produce for the first time and studied their thermal comfort properties. The results show that the washing processes have a critical importance for the tested fabrics in terms of thermal conductivity, thermal resistance, thermal absorbtivity, water vapour permeability, and heat loss. It has been also demonstrated that the fabric cleaning by using ultrasonic method enhanced the properties of tested fabrics such as thermal conductivity and % recovery. It was also noted that 15 minutes ultrasonically washed fabrics had significantly lower thermal resistance as compared to conventionally washed fabrics.     

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.     

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.     

Microwave-mediated rapid tailoring of PET fabric surface by using environmentally-benign,biodegradable Urea-Choline chloride Deep eutectic solvent

Deep eutectic solvent, urea-choline chloride (URC), was used to control surface of poly(ethylene terephthalate) (PET) fabric under microwave irradiation with or without sodium hydroxide (NaOH) for hydrophilic-hydrophobic properties. Wicking and contact angle evaluations indicated that the URC-treated PET fabric drastically changed its surface characteristics from highly hydrophobic to highly hydrophilic (or vice versa) by carefully adjusting alkali concentration and microwave irradiation time. For instance, an instant wicking was achieved on URC-treated PET with 1 % NaOH at 60 s of microwave irradiation, whereas highly hydrophobic PET surface with 2600 s wicking time and 135.6 ° contact angle was acquired by adding 5 % NaOH at the same microwave irradiation. Methylene Blue staining and FTIR analyses suggested that a minimal hydrolysis occurred through URC-treatment with NaOH under microwave irradiation and hydrophilicity was mainly achieved by physical disruption of the fiber. The treated fabrics were further analyzed by DSC, TGA, and SEM. Therefore, a rapid control of hydrophilic-hydrophobic surface of PET fabric was achieved with a little side reaction by using environmentally-benign, biodegradable URC deep eutectic solvent.     

Cotton fabric mechanical properties affected by post-finishing processes

Following the work done previously [1]. In this paper, the effect of various post-finishing agents on the low stress mechanical and surface properties of dyed cotton fabrics, as well as their handle value have been studied. The mechanical properties of the treated cotton fabrics were measured by the famous KES-FB system. It has been found that cotton fabric mechanical properties and fabric handle can be modified by not only the external finishing agents but also the internal finishing agents which are used for correcting the inherent defect of the fabrics. The results in this report will inform the textile industry in engineering required fabric properties with appropriate finishing processes.     

Facile fabrication of superhydrophobic cotton fabric from stearyl methacrylate modified polysiloxane/silica nanocomposite

The stearyl methacrylate modified polysiloxane/nanocomposite was synthesized by graft copolymerization between stearyl methacrylate modified polysiloxane with pendent epoxy groups and amino-functionalized nano silica. Then it was utilized to fabricate the superhydrophobic cotton fabric by one-step method. The structures, chemical compositions, thermal properties, surface morphology and wettability were characterized by Fourier Transform Infrared Spectrum (FT-IR), X-ray photoelectron spectroscopy (XPS), Thermo-gravimetric analyzer (TGA), Scanning electron microscopy (SEM) and Static contact angle analyzer. Results showed that a hydrophobic polysiloxane film and many nano-scaled tubercles were coated on the surface of the treated cotton fabrics plus their inherent microscaled roughness, which were the reasons why cotton fabric changed from hydrophilicity to hydrophobicity. In addition, with increase of the amount of nanocomposite, hydrophobicity of the treated cotton fabric would be enhanced; water contact angle of this fabric could attain 157°, which was higher than 141.5° reached by the fabric treated with stearyl methacrylate modified polysiloxane. The superhydrophobic cotton fabric also possessed favorable washing durability. On the other hand, its air permeability, color and softness would not be influenced instead.     

Evaluation of the Electromagnetic Shielding Effectiveness of Carbon-Based Screen Printed Polyester Fabrics

Electromagnetic shielding has a very emerging role in the textile applications. Screen-printing is a well-known, easy and cost effective process for textile printing. In this study, carbon black and graphite particles were used to impart electromagnetic shielding property to polyester fabric by screen printing technique. To this aim, printing pastes containing carbon materials were prepared with different binder concentrations. The electrical resistance, surface morphology, color coordinates and washing fastness properties of screen printed polyester fabrics were investigated. The washing durability of electromagnetic shielding effectiveness of carbon based printed fabrics as a function of binder concentration have also been studied. Electromagnetic shielding effectiveness was evaluated in the frequency ranges between 15-3000 MHz. The results showed that the electromagnetic shielding properties of fabric were affected by increased binder concentration. The most durable electromagnetic shielding effectiveness after washing process was obtained at highest binder concentration. The surface morphologies and color difference values of printed fabrics after washing process also provided a positive contribution.     

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.     

Effects of NCO/OH ratios and polyols during polymerization of water-based polyurethanes on polyurethane modified polylactide fabrics

Polylactides (PLAs) are a type of environmental friendly material. PLA fabrics feature excellent performance in terms of texture, comfort, curling effect, crystallinity, and transparency. However, because of its aliphatic polyester structure, PLA is relatively fragile as compared with the commercially available products like PET or Nylon. This study adopted water-based polyurethane (PU) to modify the surface of PLA fabrics, thereby enhancing the fabrics’ mechanical properties. Various polyols such as polytetrahydrofuran (PTMG), polycaprolactone diol (PCL), and polycarbonates diol (PC) were used and various NCO/OH molar ratios were designed in this study. As the PLA fabric was processed by dipping in various PU dispersions, it was found that the breaking strength of the fabric was increased, while its elongation at breakage decreased. Particularly, the breaking strength of the fabric modified by PUD50PC containing 50 weight percent of PC and two other polyols was the most prominent showing an 80 % increase in strength. Furthermore, the abrasion resistance of the PUD50PC-modified PLA fabric showed a roughly 6 times increase as compared to the plain PLA fabric. SEM images also reveal that after processing with water-based PU, the PLA fibers are bonded tightly with the water-based PU molecules to increase the breaking strength of the PLA fabrics.     

Optimization of papain treatment for improving the hydrophilicity of polyester fabrics

The goal of this study was to establish optimal conditions for improving the hydrophilicity of polyester fabrics. The hydrolytic activity of papain was determined by measuring the number of carboxylic groups in the treatment solution. Papain treatment conditions-such as pH, temperature, treatment time, and enzyme concentration-were optimized by measuring hydrolytic activity, moisture regain, and wettability. Optimal papain treatment conditions were identified as a pH of 7.5, temperature of 30 °C, treatment time of 60 min, and papain concentration of 100 %(o.w.f.). The moisture regain for polyester fabrics treated with papain improved to 1.28±0.02 %, a 2.7-fold increase compared to that of untreated polyester fabrics. As the hydrolytic activity increased, the moisture regain and wettability of the treated fabrics improved. L-cysteine and sodium sulfite did not affect the moisture regain of papain-treated polyester fabrics.     

A novel method to analyze the moisture liberation of textile fabrics

In this paper, a purpose-built apparatus was used to analyze the moisture liberation of textile fabrics. Fabrics were wetted and placed in an air-conditioned room to test the variation of weight and surface temperature during the process of moisture liberation. Effects of textile materials and fabric structures on the velocities of moisture liberation of fabrics were analyzed; the temperature variation and its relationship with moisture regains of fabrics in the moisture liberation were also studied. Moisture liberation velocities of polyester and silk fabrics are much higher than that of wool and cotton fabrics. For the same textile materials, knitted fabrics absorbed more water and thus took longer time to liberate the water. The surface temperature of fabrics showed three stages during moisture liberation. With the decrease of moisture regain, fabric temperature decreased gradually and jumped quickly to ambient temperature. In this way we could evaluate the moisture desorption of fabrics and develop quick-drying fabrics with imporved moisture and thermal properties.     

Parametric study of CF4-plasma on the hydrophobicity of polyester synthetic leather

Atmospheric pressure plasma (APP) technology has been proven to be an effective method for improving the hydrophobicity of fabric surface. While many researchers have worked on apparel fabrics, polyester and synthetic leather fabrics, popular in the luxury textile market, have been examined rarely. In this regard, this paper reports the effects of APP treatment using tetrafluoromethane (CF₄) as the polymerizing monomer on hydrophobicity of polyester synthetic leather. The polyester synthetic leather samples were treated under various parameters and hydrophobicity was found to be greatly enhanced under a certain range of treatment conditions. An optimization of the treatment parameters was conducted and the results showed that a hydrophobic surface with a contact angle of 106 ° was achieved, compared to the untreated sample’s 0 °.     

Optimization of acid cellulose enzyme concentration to reduce pilling of bamboo fabric: An objective assessment approach

Enzymes are being extensively used in industry as they are environmentally friendly. They show a variety of advantages over chemicals, like their specificity, high efficiency and eco-friendliness. Nowadays different kinds of cellulase enzyme mixtures are commercially formulated for the finishing of cellulosic fabrics. This study investigated the effect of acid cellulase treatment on bamboo knitted-fabric to reduce pill. It has been observed that specific range of concentration only can effectively reduce pills with substantial weight loss. The common process and method followed by a textile chemist to optimize or standardize the concentration of enzyme treatment to reduce pill is still cumbersome and doubtful. A quicker and objective method is proposed to optimize the concentration of enzyme. The effectiveness is evaluated using standard Martindale tester and the weight loss of the fabric.     

Comparative Performance of Copper and Silver Coated Stretchable Fabrics

The present work described the development of multifunctional, electrically conductive and durable fabrics by coating of silver and copper particles using a dipping-drying method. The particles were directly grown on fabric structure to form electrically conductive fibers. Particles were found to fill the spaces between the microfibers, and were stacked together to form networks with high electrical conductivity. The electrically conductive fabrics showed low resistance with high stretch ability. The utility of conductive fabrics was analyzed for electromagnetic shielding ability over frequency range of 30 MHz to 1.5 GHz. The EMI shielding was found to increase with increase in concentration of copper and silver particles. Furthermore, the heating performance of the copper and silver coated fabric was studied through measuring the change in temperature at the surface of the fabric while applying a voltage difference across the fabric. The maximum temperature (119°C for silver and 112°C for copper) were obtained when the applied voltage was 10 V. Moreover, the role of deposited particles on antibacterial properties was examined against pathogenic bacteria such as Staphylococcus aureus and Escherichia coli. At the end, the durability of coated fabrics was examined against several washing cycles. The fabrics showed good retention of the particles, proved by small loss in the conductivity of the material after washing.     

Tear properties and meso-scale mechanism of multi-axial warp-knitted fabric from various architectures: Studied by photography

Tear properties tests of three kinds of multi-axial warp-knitted (MWK) fabric: triaxial fabrics (?45 °/90 °/+45 ° and ?45 °/0 °/+45 °) and biaxial fabric (?45 °/+45 °) were respectively implemented along the orientations of 0 °, 45 ° and 90 °. Load-displacement curves were well obtained. The high-speed camera was employed to observe the whole tear damage process and series of still images were picked up to analyze the meso-scale mechanism of the extension and displacement of tows on oriented layers. The results indicated the tear properties of MWK fabric are closely related to the orientations of the layers and the deformation mechanism of the layers. Stitching yarns incarnated significant effects in restricting the deformation procedures of tows.     

The combined use of cutinase,keratinase and protease treatments for wool bio-antifelting

A combined treatment method of cutinase, keratinase, and protease was applied in the wool processing to modify the wool properties. The results demonstrated that individual protease treatment did not obviously improve the wettability and anti-felting property of wool fabrics. The combined process of cutinase and protease seemed more efficient than the keratinase-protease method, the obtained wettability and anti-felting ability of wool fabric were more encouraging. The combined use of cutinase, keratinase, and protease treatments endowed wool with more satisfactory properties compared to other methods. The contact angle of the protease-treated wool fabric reduced to 66 ° and the area shrinkage decreased to 5.2 % with an acceptable strength loss of 14 %. Reaction mechanism of the three-step enzymatic process was proposed in this paper. The data from amino acid analysis revealed the cooperative actions of cutinase, keratinase, and protease treatments during the combined enzymatic processing.     

Dyeing and fastness properties of a reactive disperse dye on PET, nylon, silk and N/P fabrics

Dyeing and color fastness properties of a reactive disperse dye containing an acetoxyethylsulphone group on PET, Nylon, silk and N/P fabrics were examined. The reactive disperse dye exhibited almost the same dyeing properties on PET fabric as a conventional disperse dye except the level of dye uptake. The most appropriate pH and dyeing temperature for the dyeing of Nylon fabric were 7 and 100°C respectively. The build-up on Nylon fabric was good and various color fastnesses were good to excellent due to the formation of the covalent bond. Application of the reactive disperse dye on silk fabric at pH 9 and 80°C yielded optimum color strength. The rate of dyeing on Nylon fabric was faster than that on PET fabric when both fabrics were dyed simultaneously in a dye bath, accordingly color strength of the dyed Nylon was higher. The reactive disperse dye can be applied for one-step and one-bath dyeing of N/P mixture fabric with good color fastness.     

Statistical Modeling of Thermal Properties of Biobased Compostable Gloves Developed from Sustainable Polymer

Polylactic acid (PLA) is a biodegradable and compostable polymer obtained from annually renewable resources and is acknowledged to be sustainable and non-polluting polymer with substantial commercial prospective as a textile fiber however, there is lack of literature on apparel applications of this polymer. Therefore in this study it was aimed to develop biobased compostable gloves from PLA draw textured melt spun yarns and to examine the effect of yarn linear density, fabric structure and stitch density on thermo-physiological comfort and moisture management properties of PLA based gloves. 100 % PLA based multifilament yarns of two different linear densities were melt spun and later draw textured on false twist texturing machine to be used for gloves knitting. Single jersey and rib structures were produced with two different stitch densities to investigate their effect on thermal conductivity, thermal resistance, relative water vapour permeability, air permeability and moisture management properties of the gloves. Minitab statistical software was employed to analyze the results of test samples. The coefficients of determinations (R² values) presented good estimation capability of the established regression models. The outcomes of this research may be useful in determining suitable manufacturing requirements of PLA based gloves to accomplish precise thermo-physiological and moisture management properties.