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.     

Atmospheric plasma treatment of polypropylene fabric for improved dyeability with insoluble textile dyestuff

Polypropylene (PP) fabrics were activated by an atmospheric pressure, dielectric barrier discharge to optimize the effects of some discharge parameters on the dyeability of PP fabrics. Air and argon plasmas were used to modify the surfaces of the fabrics, and the effects on dyeability were investigated when the treated fabrics were dyed by leuco and pigment forms of vat dyestuffs. Surface properties of plasma-treated samples were characterized by Fourier transform infrared spectroscopy (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Vat-dyed samples showed a significant increase in color strength when PP fabrics were pretreated with atmospheric pressure plasmas of either argon or air.     

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.     

Simultaneous synthesis of nano ZnO and surface modification of polyester fabric

In this study, synthesis of zinc oxide nanoparticles was carried out along with the hydrolysis of polyester fabric using sodium hydroxide to increase the surface activity and enhance the nanoparticles adsorption. The polyester fabrics were treated with zinc acetate and sodium hydroxide at different bath conditions, ultrasound and stirrer, resulting in formation of ZnO nanospheres and ZnO nanorods. The presence of zinc oxide with different shapes on the surface of the polyester fabrics was confirmed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Also, the X-ray diffraction patterns established the composition of wurtzite structure of zinc oxide. The self-cleaning property of treated polyester fabrics was evaluated through discoloring dye stain under sunlight irradiation. The antibacterial activities of the samples against two common pathogenic bacteria including Escherichia coli and Staphylococcus aureus were also assessed. The results indicated that the photocatalytic and antibacterial activities of the ultrasound treated polyester fabrics were superior compared to the stirrer treated samples.     

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.     

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.     

Effect of process variables on surface properties of low-pressure plasma treated polypropylene fibers

Plasma surface treatment has been extensively applied in the textile industry for the modification of polymer materials. In this study, polypropylene (PP) fibers in the form of a nonwoven web were treated with low-pressure plasma (air, N₂, Ar) for different treatment time (5–40 min). Powers varied from (50–500 W). Surface properties were studied by measuring wetting time and hydrophilisation diameters after an exposure time of 20 seconds. This study showed that the best conditions for the surface modification of nonwoven PP, with low pressure plasma were a power of 500 W and a treatment time of 30 minutes. Ageing has some effect on the wettability of treated samples.     

Relationship between tactual roughness judgment and surface morphology of fabric by fingertip touching method

The so-far studies on the physical determinants of roughness sensation of fabrics have considered only the profile amplitude of fabric surface, while it is poor to discriminate regular surfaces and doesn’t involve the interlocking interaction between fabric morphology and fingerprint. This work aims to compare the capability of the amplitude and spectral contents of fabric morphology in scaling the tactual roughness sensation by fingertip touching method. A set of experiments ranking fabrics on perceived tactual roughness by fingertip touching method were designed, and the Mean Deviation of the Surface profile (SMD), the texture spatial period, the maximum harmonic amplitude and the harmonic frequency were extracted from the fabric morphology. The concordance between the roughness sensation rank and the rank of each of four morphology indexes were compared. The experimental results showed that the spatial-intensive cues, i.e. the amplitude and the texture spatial periods were equivalent in scaling tactual roughness sensation of fabrics and the single spectral component was poor. Furthermore, it was observed that the features with a large length scale could dominate in subjects perceiving physical roughness. Accordingly, the speculation of this domination was tested, and it was confirmed that the texture spatial period dominated in the tactual roughness judgment of fabrics with texture-patterns spacing more than human fingerprint wavelength. It was concluded that the spatial coding works for the tactual roughness judgment of fabrics and the contribution of the spatial amplitude intensity depended on the contrast of texture spatial period to human fingerprint wavelength.     

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.     

Assessment of the surface roughness of cotton fabrics through different yarn and fabric structural properties

The effects of some yarn properties (i.e. type, count, twist level, ply number, unevenness and crimp) and fabric constructional properties (i.e. cover, thickness and balance) on surface roughness values of cotton woven fabrics were investigated. A general overview of the results showed that surface roughness values of fabrics were affected from yarn and fabric properties and the effects were related to fabric balance, fabric cover (not cover factor), fabric thickness and crimp values of yarns in fabric structures. Surface roughness values of fabrics decreased as yarn fineness and yarn twist levels increased but as yarn ply number decreased. Also, surface roughness values gradually decreased from open-end yarn constituting fabrics to combed yarn constituting fabrics. Results showed that different properties of yarns caused changes in yarn crimps in fabric structure and also governed the changes in fabric balance, as well as changes in roughness of fabric surfaces. The changing properties of yarns and impact of these properties on fabric construction affected the formation of cotton fabric surfaces from smooth to coarse.     

Effect of the atmospheric plasma treatment parameters on surface and mechanical properties of jute fabric

Plasma treatment is a kind of environmentally friendly surface modification technology, which has been widely used to modify various materials in many industries. Plasma treatment improves the fiber-matrix adhesion largely by roughening the surface of fibers to increase mechanical interlocking between the fiber and the matrix. For this aim, the effect of atmospheric air plasma treatment on jute fabrics has been discussed in this study. The plasma treatment has been employed at different powers and time intervals. The effects of plasma treatment on fiber properties were revealed by wickability, surface roughness, fiber tensile test and pull-out tests. The effect of plasma treatment on functional groups of jute fibers was observed by attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR). Scanning electron microscopy (SEM) images showed the etching effect of plasma treatment on the surface. It can be concluded that plasma treatment is an effective method to improve the surface and mechanical properties of jute fabrics to be used for composite materials.     

The effects of humidity on the surface modification of wool fabric through atmospheric pressure plasma jet

Current research was carried out on hydrophilic wool fibers at three different humidity conditions through atmospheric pressure plasma jet (APPJ). Samples were taken to evaluate surface microscopic morphology, surface roughness, directional friction effect (DFE), and surface chemical composition. The scanning electron microscope (SEM) and fiber friction coefficient test (FFT) results show that wetting pretreatment has significant effect on surface etching and DFE, but very limited effect on surface roughness. Allwörden reaction and X-ray photoelectron spectroscopy (XPS) results reveal that extra moisture changes C, O, N, S contents and their related characteristic functional groups, therefore increases etching degree on wool fiber surface scales. It was concluded that APPJ treatment is effective in processing wool fiber with high moisture contents.     

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.     

Photo-oxidation of polypropylene fibers exposed to short wavelength UV radiations

Polypropylene fibers were exposed to short wavelength radiations (λ=253.7 nm). The samples were analyzed by microscopy, staining, FTIR spectroscopy, tensile testing, and X-ray diffraction. The short-wavelength UV irradiation produces much more reactive radicals such as peroxy and alkoxy groups, which speeds up the photo-oxidation process. The products were identified by FTIR spectroscopy to be alcohols, peroxides, ketones, aldehydes, carboxylic acids, and anhydrides. Comparison of the amount of functional groups leads to an estimation of the mechanism of photo-oxidation. The short-range order increases during the photo-oxidation and the long-range order or crystalline fraction remains intact. Transverse cracks appeared on the surface of fibers after a long period of exposure to the radiation. A proposed mechanism for crack formation is the removal of the photo-oxidation products and the restructuring of the residuals. Similar to the thermal oxidation, mass loss and density increase are the main reasons for the crack formation in photo-oxidation.     

Application of silver nanoparticles to cotton fabric as an antibacterial textile finish

A novel nano-silver colloidal solution was prepared in one step by mixing AgNO₃ aqueous solution and an amino-terminated hyperbranched polymer (HBP-NH₂) aqueous solution under vigorous stirring at room temperature. All results of Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM) and UV/Visible Absorption Spectrophotometry indicated that silver nanoparticles had been formed in colloidal solution. Cotton fabric was treated with nano-silver colloid by an impregnation method to provide the cotton fabric with antibacterial properties. The whiteness, silver content, antibacterial activity and washing durability of the silver-treated fabrics were determined. The results indicated that the silver-treated cotton fabric showed 99.01 % bacterial reduction of Staphylococcus aureus and 99.26 % bacterial reduction of Escherichia coli while the silver content on cotton was about 88 mg/kg. The antimicrobial activity of the silver-treated cotton fabric was maintained at over 98.77 % reduction level even after being exposed to 20 consecutive home laundering conditions. In addition, the results of scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) confirmed that silver nanoparticles have been fixed and well dispersed on cotton fabrics’ surface and the major state of the silver presented on the surface was Ag⁰.     

Facile fabrication of PVAc-g-PVDF coating on surface modified cotton fabric for applications in oil/water separation and heavy metal ions removal

Selective separation is an effective method for the removal of heavy metal ions and waste oil from wastewater. Polyvinylidene fluoride (PVDF) was functionalized with polyvinyl acetate (PVAc) by in-situ polymerization, and novel PVAc-g-PVDF coating on surface modified cotton fabric were prepared. The contact angle (CA), pure water flux (PWF) and self-cleaning ability of coated cotton fabric were investigated in detail. In addition, the separation performance of coated cotton fabric was reflected by the removal of heavy metal ions in simulated wastewater. The results revealed that the PVAc-g-PVDF-coated cotton fabric was free of waste oil adhesion and was self-cleaning from waste oil in aqueous environment. Meanwhile, this coated cotton fabric can effectively separate oil/water mixtures with a high flux and high oil rejection, and was easily recycled for long-term use. More importantly, the heavy metal ions rejection ratio and adsorption capacity of cotton fabric were also improved with the addition of PVAc-g-PVDF coating. PVAc-g-PVDF-coated cotton fabric exhibited excellent rejection stability and reuse performances after several times fouling and washing tests. It can be expected that the present work will provide insight into a scaled-up fabrication process of PVAc-g-PVDF coating for purifying wastewater.     

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.     

关于四川省抢播套作大豆、弥补夏旱损失的建议

根据<四川省气候灾害实时监测预警系统>监测,四川省五月底、六月初有89个县(市)发生了20～28 d的夏旱,其中60个县(市)夏旱仍在继续进行,主要分布在盆地中部和南部、川西高原西南部等地区.为此,对自贡、宜宾、内江、资阳等地区的旱情进行了实地考察.所到之地,正值玉米需水关键时期--抽雄期,由于干旱严重,大部分玉米株高不足两尺,下部叶片已经变黄,中上部叶片开始萎蔫.     

Surface treatments of jute fabric: The influence of surface characteristics on jute fabrics and mechanical properties of jute/polyester composites

In this study, jute fabrics were modified by alkali, micro-emulsion silicon (MS) and fluorocarbon based agents (FA) in order to enhance the interfacial adhesion between the polyester matrix and the jute fiber. X-ray photoelectron spectroscopy (XPS) and contact angle measurements were used to characterize fiber surfaces. The effects of various surface treatments on the mechanical and morphological of jute/polyester composites were also studied. All surface treatments were shown to improve the tensile, flexural strengths and interlaminar shear strengths of the composites. Moreover, the maximum improvement in the mechanical properties was obtained for the FA treated jute/polyester composites. SEM micrographs of the tensile fracture surface of jute/unsaturated polyester composites also exhibited improvement of interfacial and interlaminar shear strengths by the alkali, MS and FA treatments of jute fibers.     

Synthesis of HBP-HTC and its application to cotton fabric as an antimicrobial auxiliary

A quaternary ammonium compound, 2-hydroxypropyltrimethylammonium chloride amino-terminated hyper-branched polymer (HBP-HTC), was synthesized from an amino-terminated hyperbranched polymer (HBP-NH₂) and 2,3-epoxypropyltrimethylammonium chloride (EPTAC) as a grafting agent in aqueous solution. Its molecular weight and possible structure were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (¹H-NMR). The cotton fabric was treated with 2 g/l HBP-HTC aqueous solution for 30 min at room temperature to provide the cotton fabric with antimicrobial properties. The antimicrobial activities of the HBP-HTC aqueous solutions and the HBP-HTC treated cotton fabrics were evaluated quantitatively. The results indicated that the HBP-HTC treated cotton fabric showed 99.92 % reduction of bacteria S. aureus and 99.66 % reduction of bacteria E. coli, respectively. The antimicrobial activities of the HBP-HTC treated cotton fabrics were maintained at over 99.00 % reduction level even after being exposed to 20 consecutive home laundering conditions.