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Abstract: Al(OH)3 nanoparticles (ATH NPs) and phosphorylated cellulose nanofibrils (PCNFs) were used as user-friendly and comfortable coating components on flame-retardant fabric to improve its thermophysiological comfort and high-intensive heat protection properties. The effect of the PCNF imprinting and its attachment after the post-printing of a hydrophobic polyacrylate (AP) on the same (back side) or the other (front) side of the fabric, with and without the addition of ATH NPs, was considered, to maintain the front side (facing the wearer) as hydrophilic while keeping the back side (facing the outside) hydrophobic. The amount of coatings applied and their patterning were studied, varied with the ATH NPs’ concentration (1.7, 3.3 and 6.7 wt%) and screen mesh size used (60 and 135), based on the coating’ mass, fabric’s air permeability, thickness and microstructure. The reduced moisture build-up (55%), increased the water vapour (13%) and heat (12%) transfer from the skin, were assessed by applying PCNF under the AP, being more pronounced in the case of using a 135 mesh-sized screen, given the smaller, more densely distributed, thinner and imprinted pattern coatings. These effects were further improved by the addition of nanoporous ATH NPs, which allowed more homogeneous spreading of the moisture and its faster transport. Such a treatment also shifted the fabric’s degradation temperature towards higher values (up to 15°C), retained up to 30% of high-heat flux (21 kW/m2), prolonged the time to ignition by 11 s and reduced the total heat released by up to 60%, thereby providing better protection when exposed to the heat, due to the presence of the phosphorous (PCNF) promoted generation of an Al2O3 char acting as a barrier layer, while also reducing the production of heat and generation of smoke by 75%.
Keywords: tekstilna tehnologija, ognjevaren tekstil, Al(OH)3 nanodelci, celulozni nanofibrili, tiskanje tekstilij, optične lastnosti, termofiziološko udobje, toplotna zaščita, flame-retardant textile, Al(OH)3 nanoparticles, phosphorylated cellulose nanofibrils, screen-printing, thermophysiological comfort, heat protection
Published in DKUM: 12.07.2023; Views: 455; Downloads: 14
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Abstract: Polymers and surfactants are essential ingredients of the printing paste. Polysaccharides are used commercially to thicken, suspend or stabilise aqueoussystems. Also they are used to produce gels and to act as flocculates, binders, lubricants, to serve as modifiers of film properties, and have a function as adjusters of rheological parameters. Surfactants, on the other hand, perform numerous functions acting as dispersants, wetting agents, emulsifiers and antifoaming agents. The rheological properties of polysaccharide thickeners (guar gums with different substitution levels and different producers) at different concentrations and temperatures and, second,the effects produced by the addition of nonionic surfactants (polyoxyethylene stearyl alcohols with different numbers of EO groups) have been studied under linear and nonlinear shear conditions. Experimental data have been correlated with the different modelsČ flow curves with the Cross, Carreau and Meter-Bird model, and mechanical spectra with the generalized Maxwell model and Friedrich-Braun model. The surface tensions of aqueous systems containing polysaccharide andžor surfactants have been determined overextended concentration ranges in order to detect the CMC conditions and toprovide a better understanding about the polysaccharide-surfactant interactions.
Keywords: textile printing, printing pastes, polysaccharides, thickeners, rheology, viscoelasticity, surfactants, guar gum
Published in DKUM: 01.06.2012; Views: 2589; Downloads: 88
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Abstract: The influence of four non-ionic surfactants (isododecyl and cetyl polyoxyethylene ethers) on aqueous polysaccharide solutions (sodium alginate, guar gum, and sodium carboxymethyl guar), applicable for textile printing pastes, were studied via rheological measurements. Rheology of polysaccharide-surfactant solutions in aqueous matrices is primarily governed by polymer content, which imparts marked shear-thinning and viscoelastic character to the system. Such properties are modulated in moderate but sensible way by changes in surfactant concentration or type. Above 3% surfactants addition to non-substituted guar gum solutions results in a significant impact leading to phase separation and a particular strongly associated phase is formed due to hydrogen bonds between ethylene oxy units from the surfactant and primary hydroxyl groups in guar. A satisfactory fitting of viscosity data is obtained with both the Cross equation and the Roberts-Barnes-Carew model. The experimental results of mechanical spectra can be described quite satisfactory with both the Friedrich-Braun and the generalized Maxwell models.
Keywords: textile printing, polysaccharide thickeners, rheology, non-ionic surfactant, polymer-surfactant interactions, viscoelasticity
Published in DKUM: 01.06.2012; Views: 2016; Downloads: 91
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Abstract: An attempt of using artificial neural networks for the prediction of dzes in textile printing paste preparation is presented. An existing collection of printed samples served as the basis for neural network training. It consists of 1340 samples printed using either a single dze or a combination of two dzes. First the proper combination of dzes was determined, because in most cases onlz two dzes are combined in the printing paste. Then the necessarz concentration of each dze was predicted. The reflectance value, and the colourvalues L*, a*, b* serve as input data and the known combination and concentrations of dzes for each sample were the targets. Some variations of neural network were tested, as well as various numbers of neurons in the hidden lazer. In addition, the influence of the training set organisation was examined, together with the number of learning epochs on the learning success.
Keywords: artificial neural networks, textile printing, colour recipe prediction
Published in DKUM: 31.05.2012; Views: 2012; Downloads: 65
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