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[en] The synthesis of Trimethylol Melamine (TMM) precondensate was carried out by the controlled reaction of formaldehyde with melamine, which belonging to class of partially methylolated thermosetting resins. The product was clear, transparent, viscous and miscible with water. The refractive index, density and maximum absorption of the synthesized TMM was determined. The dyed (C.I. Direct Red 2) cotton and rayon specimens were impregnated with synthesized precondensate (TMM) and Fix M-3 (commercially available trimethylol melamine of BSF product), cured at 150 deg. C for 3 min using curing catalyst. The performance of the synthesized and Fix M-3 evaluated using rubbing, washing and light fastness tests. The rubbing fastness to crocking, color fastness to washing and light fastness is reported and found to be dependent on the fixing efficiency of fixer. The fastness to light is found to be dependent on the aromatic character of melamine ring which obviously due to the preferably absorption in the UV region. (author)
[en] The 3D printing belongs to the rapidly emerging technologies which have the chance to revolutionize the way products are created. In the textile industry, several designers have already presented creations of shoes, dresses or other garments which could not be produced with common techniques. 3D printing, however, is still far away from being a usual process in textile and clothing production. The main challenge results from the insufficient mechanical properties, especially the low tensile strength, of pure 3D printed products, prohibiting them from replacing common technologies such as weaving or knitting. Thus, one way to the application of 3D printed forms in garments is combining them with textile fabrics, the latter ensuring the necessary tensile strength. This article reports about different approaches to combine 3D printed polymers with different textile materials and fabrics, showing chances and limits of this technique. (paper)
[en] Atmospheric plasma technology finds novel applications in textile industry. It eliminates the usage of water and of hazard liquid chemicals, making production much more eco-friendly and economically convenient. Due to chemical effects of atmospheric plasma, it permits to optimize dyeing and laminating affinity of fabrics, as well as anti-microbial treatments. Other important applications such as increase of mechanical resistance of fiber sleeves and of yarns, anti-pilling properties of fabrics and anti-shrinking property of wool fabrics were studied in this work. These results could be attributed to the generation of nano roughness on fibers surface by atmospheric plasma. Nano roughness generation is extensively studied at different conditions. Alternative explanations for the important practical results on textile materials and discussed.
[en] The textile processing uses an important amount of water during their production, while generating effluents that have various types of chemicals, such as surfactants, peroxides, acids, salts and dyes. Considering their complexity, these effluents commonly have high toxic load and coloration. Advanced Oxidative Processes have been used to improve the treatment of this type of effluent, complementing the biological treatment. Electron beam irradiation has been proposed as a technology for treatment of textile effluents, in order to reduce toxicity, coloration, chemical oxygen demand, and other parameters. The objectives of this work were to evaluate the toxicity of chemical compounds used in the cotton fibers, and the textile effluent (containing red reactive dye 239) to aquatic organisms; and to evaluate the efficiency of electron beam irradiation in treatment of these contaminants. Acute toxicity assays were performed with aquatic organisms Vibrio fischeri bacteria and Daphnia similis crustacean. For chronic effect, D. similis crustacean was used, being evaluated the reproduction, sublethal effects and body length after 21 days exposure to textile effluent containing reactive dye Red 239. The effluent as well as organic compounds were irradiated in electron beam accelerator, with dose range between 0.5 and 15 kGy. The irradiation treatment improved the toxicity, color, chemical oxygen demand and total organic carbon of the effluent. Regarding acute toxicity for raw effluent, the mean EC 50% was between 2.93 ± 0.13 and 9.28 ± 0.32 for D. similis and 5.65 ± 0.16 and 8.40 ± 1.45 for V. fischeri. The electron beam treatment was effective in reducing the toxicity of the samples, 5 kGy: EC 50% = 16.36 ± 5.37, representing 61.43% toxicity removal for D. similis and 15.05 ± 2.93, 50.73% toxicity removal for V. fischeri. While 10 kGy resulted in over 70% of acute effects removal for both organisms. Regarding color reduction, 5 kGy resulted in > 95% efficiency. Among the surfactants analyzed, the nonionic alkylene oxide and the ethoxylate were more toxic to both organisms, with mean EC 50 values below 4.5 mg L-1. For the chronic measurements, D. similis exposed to raw textile effluent (concentration 3%), sublethal effects were observed, such as dye deposition in the filtering system and eggs malformation. (author)
[en] Textile manufacturing is one of the largest industries in the world, and synthetic fibres represent two-thirds of the global textile market. Synthetic fibres are manufactured from petroleum-based feedstocks, which are becoming increasingly expensive as demand for finite petroleum reserves continues to rise. For the last three decades, spider silks have been held up as a model that could inspire the production of protein fibres exhibiting high performance and ecological sustainability, but unfortunately, artificial spider silks have yet to fulfil this promise. Previous work on the biomechanics of protein fibres from the slime of hagfishes suggests that these fibres might be a superior biomimetic model to spider silks. Based on the fact that the proteins within these 'slime threads' adopt conformations that are similar to those in spider silks when they are stretched, we hypothesized that draw processing of slime threads should yield fibres that are comparable to spider dragline silk in their mechanical performance. Here we show that draw-processed slime threads are indeed exceptionally strong and tough. We also show that post-drawing steps such as annealing, dehydration and covalent cross-linking can dramatically improve the long-term dimensional stability of the threads. The data presented here suggest that hagfish slime threads are a model that should be pursued in the quest to produce fibres that are ecologically sustainable and economically viable.
[en] The general character of textile industry wastewaters is briefly discussed. General guidelines and practice in Finland when discharging textile industry wastewaters to municipal sewer systems is described. A survey revealed that most municipalities experience some problems due to textile industry wastewaters. Pretreatment is not always practiced and in some cases pretreatment is not operated efficiently. (author)
[en] Much spider silk research to date has focused on its mechanical properties. However, the webs of many orb-web spiders have evolved for over 136 million years to evade visual detection by insect prey. It is therefore a photonic device in addition to being a mechanical device. Herein we use optical surface profiling of capture silks from the webs of adult female St Andrews cross spiders (Argiope keyserlingi) to successfully measure the geometry of adhesive silk droplets and to show a bowing in the aqueous layer on the spider capture silk between adhesive droplets. Optical surface profiling shows geometric features of the capture silk that have not been previously measured and contributes to understanding the links between the physical form and biological function. The research also demonstrates non-standard use of an optical surface profiler to measure the maximum width of a transparent micro-sized droplet (microlens).
[en] The effluents generated by textile industries are extremely toxic and dangerous to the environment. In fact, new treatment technologies for recalcitrant effluents have been tested for high dye removal efficiency. Among these technologies, electrocoagulation has been highly promising, due to its excellent results coupled with a low operating cost. This study evaluated the electrocoagulation/electroflotation process efficiency on the removal of Eriochrome Black textile dye from aqueous solution. All the experiments were carried out using aluminum electrodes due to their availability and low cost. The parameters investigated during the experiment were: electrolysis experiment time, NaCl concentration, aqueous solution pH and electric potential. In this context, the best results considering the operational parameters studied were electric potential of 7 V, values of pH low to neutral (2–7) and NaCl concentration of 2 g L−1. It has also been observed that a time of 55 min of electrolysis is sufficient for a satisfactory result, reaching a color removal efficiency of 98.5%.