Effect of carbon black nanoparticles on reflective behavior of printed cotton/nylon fabrics in visible/near infrared regions

Tuning the level of visible and near infrared (NIR) reflectance of textile surfaces is crucial for making them undetected in each environment. In this regard, samples of cotton/nylon fabrics were printed using a mixture of some special pigments and carbon black (CB) nanoparticles to produce brown, olive green and khaki shades which are present in concealment patterns of textiles employed in deserts. The effect of CB nanoparticles on Vis/NIR reflectance, air permeability, perspiration, light, wash fastnesses, and colorimetric values of each printed sample were evaluated. The presence of CB nanoparticles in printing formulations was found to cause significant decline in Near Infrared (NIR) reflectance of samples. The results showed that air permeability of samples printed containing CB nanoparticles are higher than samples printed with no CB particles. Absorbing phenomenon imposed by CB nanoparticles was fast against washing and perspiration, although printed samples indicated high to moderate light fastness. Furthermore, detectable change in visible appearance of the printed patterns was the main point of concern even at concentrations as low as 0.05 g/kg CB in printing formulation.     

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.     

Reversible and washing resistant textile-based optical pH sensors by dyeing fabrics with curcuma

Curcuma powder was used to dye cotton and polyamide 6,6 fabrics in order to produce textile-based optical pH sensors. Both fabrics showed a bright yellow color after dyeing and demonstrated color changes (towards red) when contacted with basic solutions. Color change and sensitivity differ for cotton and for polyamide. Curcuma-dyed cotton shows color changes in particular in the range of pH between 6.5 and 8.5, whilst curcuma-dyed polyamide shows a wider pH range: from 8.5 to 13.0. The stability of pH sensing to washing was evaluated. Three different kinds of washing agents were used in order to simulate the real life conditions of a garment or a cloth. Standard test methods were used when available for washing tests. The pH sensing of the curcuma-dyed fabrics demonstrated an excellent fastness to all kinds of washing. Ionic strength of the solution does not affect the color changes. Moreover, color reversibility of the fabrics was proven, too. Color change and reversibility of the fabrics was assessed by an UV-visible spectrophotometer. Spectral changes were observed at 540 nm for curcuma-dyed cotton, and at 487 and 574 nm for polyamide.     

Automatic color separating system for printed fabric using the self-organizing map network approach

We can only use color numbers, color values and design to describe the color pattern of printed fabrics, which is different from woven fabrics with yarn disposition and texture as pattern determinants. Since most printed fabrics contain many different patterns nowadays, we need more than words and simple methods to describe the color patterns. The complication in pattern identification has made the analysis and comparison difficult and will have to be conducted manually. The automatic computer color separating system for printed fabrics proposed in this paper uses unsupervised learning network to automatically separate printed colors. The system first uses color scanner to pick the image of the printed fabrics and stores it as digital image. Then, it uses wavelet transformation to minify the fabric image to reduce the calculation load of color separation and also reserve the printing structure and color distribution of the original image. It also uses LAB color model to acquire characteristic value of the colors and the Self-Organizing Map Network (SOMN) to conduct color separation. According to our experimental results, this system can rapidly and automatically complete color separation and identify repeating patterns for printed fabrics’ images.     

Computerized color separation system for printed fabrics by using backward-propagation neural network

Textile production must be coupled with hi-tech assistant system to save cost of labor, material, time. Therefore color quality control is one very important step in any textiles, however excellent the fabric material itself is, if it lacks good color, then it may still result in dull sale. Therefore, this paper proposes a printed fabrics computerized color separation system based on backward-propagation neural network, whose primary function is to separate rich color of printed fabrics pattern so as to reduce time-consuming manual color separation color matching of current players. What it adopted was RGB color space, expressed in red, green, and blue. Analyze color features of printed fabrics, use gene algorithm to find sub-image with same color distribution as original image of printed fabrics yet smaller area, for later color separation algorithm use. In terms of color separation algorithm, this paper relied on supervised backward-propagation neural network to conduct color separation of printed fabrics RGB sub-image, and utilized PANTONE® standard color ticket to do color matching, so as to realize accurate color separation.     

Digital ink-jet printing for chitosan-treated cotton fabric

In this paper, chitosan was suggested for using as a replacement for sodium alginate in the pretreatment print paste for digital ink-jet printing for cotton fabric. Pretreatment print pastes prepared from the mixture of chitosan and acetic acid with the appropriate viscosity gave satisfactory prints on the cotton fabric. Chitosan-treated cotton fabrics were digitally irk-jet printed with four different colors and the color fastness rating of the printed fabrics was satisfactory. Experimental results revealed the possibility of pre-treating the cotton with chitosan to replace the sodium alginate normally present in the pretreatment print paste recipe.     

Plasma-assisted surface modification of polyester fabric for developing halochromic properties

In the field of textiles, introducing pH-sensitive dyes onto fibrous materials is a promising approach for the development of flexible sensor. In this study, poly(ethylene terephthalate) (PET) textile surface with halochromic properties was fabricated by plasma-assisted sol-gel coating, followed by immobilization of two different azo pH-indicator dyes; namely Brilliant yellow and Congo red by conventional printing technique of fabrics. 3-aminopropyltriethoxysilane (APTES) was used as a coupling agent for attaching the pH-sensitive dyes through its terminal amines. The surface immobilization of APTES on PET fabric was conducted by the pad-dry-cure method. Moreover, the influence of oxygen plasma pre-treatment and the method of post-treatment either by oxygen plasma or by thermal treatment on the stability of sol-gel based matrix was investigated. The morphology and chemistry of 3-aminopropyltriethoxysilane coated PET surfaces were examined by using surface sensitive methods including electrokinetic and time-dependent contact angle measurements as well as X-ray photoelectron spectroscopy (XPS). In addition, fastness tests of the printed fabrics and color strength were carried out to assess the effectiveness of the fabric surface modification. Results indicate that sol-gel matrix exhibited a more stability by thermal post-treatment at 150 C for 5 min. Also, the results revealed that the printed fabrics with halochromic properties demonstrated sufficient stability against leaching by washing. The current work opens up a novel opportunity to develop flexible sensors based on fibrous materials, which have the potential to be employed in variable industrial applications.     

Investigation of mechanical properties of basalt woven fabrics by theoretical and image analysis methods

This paper explains a study conducted to evaluate mechanical properties of woven structures of basalt. The mechanical properties like shear strength and tensile strength were studied. Tensile properties of basalt hybrid and non-hybrid fabrics are predicted by computational tool and verified with experimental data. The shear strength was investigated by using picture frame fixture. The tests were recorded by a CCD monochrome camera during displacement of specimen at various positions. The images were used for image analysis program developed in MATLAB. The results of image analysis were compared with the actual experimental results. The results illustrate that the mechanical properties of fabrics experience a marked improvement when hybridization of basalt with polyester and polypropylene in different sets of weaves takes place. These findings are important requirements for using such fabrics for high-tech applications and composite forming.     

The effect of carbon black nanoparticles on some properties of air plasma printed cotton/polyamide 6 fabrics

In this study, cotton/nylon blended fabrics were treated with atmospheric air plasma at various times (30–60 s) and were subsequently printed with pastes containing carbon black nanoparticles. Properties of plasma treated fabrics such as visible-near infrared (Vis-NIR) reflectance, water contact angle, air permeability, and color fastness were measured. It was shown that increasing plasma treatment time decreases reflection level of treated fabrics in Vis-NIR region. Plasma treatment also enhanced the hydrophobicity of cotton/nylon fabrics observed by an increase in water contact angle. Plasma treated samples for 60 s demonstrated lower air permeability than those treated for 30 s. Furthermore, printed samples possessed acceptable levels of fastness against washing, light and crocking.     

Organic solvent absorption characteristics of split-type microfiber fabrics

Split-type nylon/polyester microfiber and polyester microfiber fabrics possess drapeability, softness, bulkiness, and smoothness, so that they can be applied in various industrial fields. In particular, these fabrics are able to absorb various organic solvents, and can be used as clean room materials. To investigate the chemical affinity between solvents and the compositional materials of these fabrics, the contact angle of thermally pressed film fabrics was measured with different solvents. The thermally pressed nylon/polyester fabric films showed a chemical attraction to formamide. The sorption properties of the microfiber fabrics were investigated using a real time testing device, and these tests showed that the sorption behavior was more influenced by the structure of the fibrous assembly than by any chemical attraction. The effect of the fabric density, specific weight, and sample structure on the sorption capacity and rate was examined for various organic solvents. The sorption capacity was influenced by the density and the specific weight of the fibrous assembly, and knitted fabric showed a higher sorption capacity than woven fabric. However, the sorption rate was less affected in lower viscosity solvents. On applying Poiseuille’s Law, the lower viscosity solvents showed higher initial sorption rates, and more easily penetrated into the fibrous assembly.     

Study on the Reduction Properties of Thiourea Dioxide and Its Application in Discharge Printing of Polyester Fabrics

The thiourea dioxide (TDO) was tentatively applied as a reductive discharging agent onto the discharge printing of polyester fabrics. The effect of aqueous solution temperature on the reducing capacity of TDO was thoroughly investigated by measuring oxidation-reduction potentials and hydrolysis kinetic curves. The effects of TDO on disperse dyes in aqueous solution and disperse dyes printed on the surfaces of glass substrates or polyester fabrics were investigated by analyzing the color changes before and after TDO discharge treatment. It was confirmed that TDO reduction became stronger with increasing aqueous solution temperature. TDO could destroy the chromogenic groups of the selected azo-dyes in aqueous solution and on the surfaces of glass substrates. Different from cotton and silk fabrics, the discharge effect of TDO directly depended on the compact structure of the polyester fibers. When a discharge accelerant was added into white discharge pastes with TDO, the compact structure of polyester fibers was opened up to achieve a good discharge effect. This study provides a new method for TDO development and a new strategy for the discharge printing of polyester fabrics.     

Copper functionalization of polypropylene fabric surface in order to use in fog collectors

Polypropylene fabrics were coated with copper particles using electroless plating, screen printing and wire arc spray coating techniques. Surface morphology of the fabrics was studied using optical and scanning electron microscopes (SEM). Furthermore, tensile strength, electrical conductivity, thermal conductivity, air permeability, water contact angle and fog collection efficiency of the coated fabrics were measured and the obtained results were analyzed. SEM micrographs showed that a very thin and uniform layer of copper deposited on the surface of the electroless plated polypropylene fibers. In the printed or spray coated fabrics the copper particles filled the spaces between yarns and fibers. The polypropylene electroless copper plated fabrics showed higher tensile strength, electrical conductivity, air permeability and thermal conductivity when compared with the fabrics coated with copper screen printed and copper spray coated fabrics. Finally, the obtained results showed that copper electroless plating could increase the fog collection efficiency of polypropylene fabrics considerably. As a conclusion, the surface modified copper electroless polypropylene fabrics are good candidates for fog collection in appropriate regions which need further investigations.     

Fabrication of electromagnetic shielding polyester fabrics with carboxymethyl chitosan-palladium complexes activation

Electromagnetic shielding polyester fabrics were prepared using carboxymethyl chitosan-palladium (CMCS-Pd) complexes as activation solution, followed by electroless nickel plating. CMCS-Pd complexes were prepared by the complexing adsorption between CMCS and Pd²⁺. The effects of reaction time and pH value on the adsorption of Pd²⁺ by CMCS were discussed. The maximum adsorption capacity was calculated as 4.27 mmol/g. CMCS-Pd complexes were characterized by ultraviolet (UV) spectrophotometer and Fourier transform-infrared (FTIR) spectroscopy. The induction time of electroless plating decreased gradually with the increase of Pd²⁺ concentration. The lowest surface resistance 125 mΩ/sq of the treated polyester fabric was obtained when Pd²⁺ concentration in CMCS-Pd complex was 1.5 g/l. The prepared polyester fabrics had excellent electromagnetic shielding effectiveness (SE) of 40–60 dB. The treated polyester fabrics were also characterized by scanning electron microscopy (SEM). Results showed that CMCS-Pd was effective to form an active catalyzed layer on polyester substrate and the 1.5 g/l Pd²⁺ was sufficient to initiate electroless nickel plating reaction. The CMCS-Pd complex activation and electroless nickel plating treatment caused small changes in the polyester fabrics’ tensile strength and air permeability.     

Analysis and tensile-tear properties of abraded denim fabrics depending on pattern relations using statistical and artificial neural network models

The aim of this study is to develop new pattern denim fabrics and characterize the mechanical properties of these fabrics after abrasion load. Furthermore, tensile and tear strengths of these fabrics have been analysed by using the Artificial Neural Network (ANN) and statistical model. All denim fabrics were first abraded and subsequently tensile and tearing tests were applied to the abraided fabrics seperately. Actual data generated from the tests were analyzed by ANN and regression model. The regression model has shown that tensile strength properties of the abraded large structural pattern denim fabrics are generally low compared to that of the small structural pattern and traditional denim fabrics. On the other hand, when the abrasion cycles are increased tensile properties of all denim fabrics are generally decreased. Tearing strength of weft and warp in the abraded large structural pattern denim fabrics are between small structural pattern and traditional denim fabric. On the other hand, when the abrasion cycles are increased tearing strength properties in the weft and warp for all denim fabrics are generally decreased. The results from ANN and regression models were also compared with the measured values. It is concluded that almost all values from ANN are accurately predicted compared with those of the regression model. Therefore, we suggest that both methods can be used in this study as viable and reliable tools.     

Investigation on hydrostatic resistance and thermal performance of layered waterproof breathable fabrics

Waterproof breathable layered fabrics allow water vapor passing through, but resist liquid water to pass. This ability of the fabrics to protect rain and snow water while allowing sweat vapor to evaporate from inside to outside atmosphere, leads them to be used as outdoor sportswear or protective clothing. The big challenge of enhanced hydrostatic resistance of these fabrics with proper breathability and thermal comfort has widened the research scope. This study presents an experimental investigation on hydrostatic resistance and thermal behavior of layered waterproof breathable fabrics. Six different types of hydrophobic and hydrophilic membrane laminated layered fabrics were evaluated by varying different fabric parameters in the experiment. Hydrostatic resistance and water vapor permeability of the laminated fabrics were measured by SDL ATLAS Hydrostatic Head Tester and PERMETEST respectively. Thermal properties were evaluated by ALAMBETA instrument. Moreover, FX-3300 air permeability tester was used to measure air permeability which represents the porosity of the fabrics and computer based See System software was used for water contact angle measurement on the outer fabric surface in order to determine the hydrophobic and hydrophilic properties. This experiment clearly discusses the influence of different fabric characteristics and parameters on hydrostatic resistance and thermal properties of the breathable laminated fabrics. The results show that fabric material composition, density, thickness, and hydrophobic and hydrophilic membranes have significant effects on hydrostatic resistance, breathability and thermal properties of different laminated fabrics.     

Reflectance prediction of colored polyester fabrics by a novel formula

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

Effect of using cold plasma on dyeing properties of polypropylene fabrics

The low temperature plasma (LTP) technique is used widely to modify polymer and textile materials. This paper describes the development of a plasma system for textile treatment. Polypropylene (PP) has a very low value of the surface free energy (approximately 20–25 mJ/m²). Due to low surface energy, Polypropylene has very weak hydrophilic properties. By controlling the plasma variables, such as the nature of gas, the discharge power, the pressure and the exposure time, a great variety of surface effects can be generated. In this paper, we report the effect of cold plasma of O₂ and N₂ gases at various time of exposure on the dyeing and physical properties of PP fabrics. The results show a significant increase in the color depth upon dyeing after treating PP fabrics with low temperature plasma of O₂ and N₂. For comparing the amount of fabrics dye exhaustion, we have used reflective spectrophotometer. The morphology of the modified surfaces has also been investigated using scanning electron microscopy (SEM). And also FTIR was used to examine the functional groups of the corresponding samples.     

Dyeing performance of the azo dyes containing trifluoromethyl group for polyester fabrics and its single crystal structure

The structures of disperse dyes and their intermolecular interactions have important impacts on dyeing and printing performances for polyester fabrics. The fluorine dyes show some unique molecular stability and photochemical properties. The dyeing property of the azo dye containing trifluoromethyl group for polyester fabrics, 4'-(N-acetoxyethyl-Nethyl)- amino-2-bromine-4-nitro-6-trifluoromethylazo- benzene (D1), was investigated and compared with the similar structure disperse dye. The results show that the high color yield and good exhaustion of the dyed PET fabrics could be obtained. The polyester fabrics dyed with D1 had excellent light fastness. Its single crystal was prepared and the supramolecular interactions were solved by X-ray diffraction. Dye D1 formed triclinic crystals in a trimeric packing mode. The C-F bond distances of CF3 are 1.2730 Å, 1.2240 Å and 1.2900 Å, respectively. The two benzene rings linked azo unit (-N=N-) are obviously twist. The dihedral angle of the two benzene rings is 50.23 o. There are six weak hydrogen bonds around trifluoromethyl group in the intramolecule and intermolecule. The excellent light stability of the dye should be attributed to its unique supramolecular structure.     

The enhanced electrical conductivity of cotton fabrics via polymeric nanocomposites

Enhanced electrical conductivity of cotton fabrics coated with polyaniline (PANI) and PANI/carbon coated Fe (Fe@C) and carbon coated Co (Co@C) metal nanoparticles (NPs) composites were investigated. PANI/metal nanoparticle (NP) composites were fabricated with a surface initialized polymerization method and silanization helped with chemical bonding to cotton. The volume resistivity of the samples and structural characterizations were assessed by relevant methods. The results showed that enhanced electrical conductivity, thermal stability and magnetization were obtained via polymeric nanocomposites (PNC) and all these findings revealed that PANI/metal NP PNC coated cotton fabrics would exhibit good level electromagnetic shielding performance as a function of combined electrical conductivity and magnetization which is the objective of our future studies.     

Development and characterization of light weight plant structured fabrics

Scientists and engineers are increasingly turning to nature for inspiration. Light weight textile fabrics suitable for summer dress material were developed by imitating the branching structure of a plant in order to achieve high water absorption and transportation properties. The absorption property of the fabrics was characterized by using the Moisture Management Tester (MMT) and Transplanar Water Transport Tester (TWTT). The fabrics were analyzed using optical microscopes and Optical Contact Angle (OCA) tester to understand the structure as well as the absorption behavior of these fabrics. The results indicated that plant structured fabrics have a significant faster water absorption and wicking properties over conventional weave structures, makes them highly preferable for summer-wear.