Hasil untuk "Textile bleaching, dyeing, printing, etc."

Murat Ayberk Baran, Behcet Becerir

Being the first commercially available wholly synthetic textile fiber which was introduced to the market in 1939, nylon fibers are one of the most frequently consumed synthetic fibers. Direct dyes were commercially produced in the early 20th century and had been the preferred method of dyeing of cellulosic fibers together with vat dyes until the discovery of reactive dyes. The most important property of direct dyes is their easy dyeing but with a disadvantage of building up weak bonds within the fiber. Chemical mordants were used mainly in the application of natural dyes to hold and retain the dye molecules in textile fibers. In this research, nylon 6,6 fabric was dyed with four direct dyes of different hues in the presence of mordants (eight metallic and one bio-mordant) to obtain better exhaustion, fixation, and coloration properties. Pre-mordanting, meta-mordanting, and post-mordanting methods were used and the dyeings were performed at 1% owf at pH 5. Percentage of dyebath exhaustion (%E), percentage fixation (%F), and overall fixation (%T) were calculated after pyridine extraction. Wash and light fastness tests were applied on the dyed samples. The results were discussed via color strength (K/S), %E, %F, %T, and CIELAB color differences (ΔE ab *). The results revealed that mordant usage improved the coloration properties of direct dyes on nylon fabrics. The %E, %F, and %T results changed according to the independent variations of dye hue, mordant, and mordanting method. Certain mordants and mordanting method gave the best coloration and fastness results for the dyes under test.

Yugesh Mani Tiwari, Saroj Kumar Sarangi, Ashwani Kumar Singh et al.

As the world shifts toward biodegradable materials to reduce environmental pollution, natural fiber-reinforced composites are gaining attention as sustainable alternatives to synthetic composites. However, natural fibers exhibit high moisture absorption and poor interfacial bonding with polymer matrices, affecting the mechanical properties of the composites. This study addresses these challenges by reinforcing polyester resin with untreated and alkali-treated Novel Grewia flavescens fiber (GFF) to enhance composite performance. Alkali treatment (5% NaOH, 45 min) was used to reduce fiber hydrophilicity and improve surface roughness, leading to better fiber-matrix adhesion. Composites were fabricated using the short fiber with fiber loadings of 10%, 20%, 30%, 40%, and 50% by weight. Mechanical characterization, including tensile, flexural, and impact tests, revealed that the optimal mechanical properties were achieved at 40% fiber reinforcement, with treated fibers outperforming untreated ones. A hygroscopic test further evaluated the water absorption behavior of the composites. The findings demonstrate that alkali treatment significantly improves the mechanical and moisture resistance properties of Grewia flavescens fiber-reinforced polyester composites, making them a promising material for eco-friendly applications

Anna Wyrostek, Katarzyna Czyż, Kamila Hapka

Sheep’s wool is a renewable, constantly growing resource, so it needs to be developed. Originally, it was mostly used in the textile industry, but the replacement by other materials resulted for some breeds in the deterioration of its quality and the need to look for alternative uses. Today, thanks to its properties, in addition to its traditional uses in a wide range of textiles, sheep’s wool is also used as an insulating material, fertilizer, or sorbent. In this research, wool originated from 3 Polish breeds of sheep, Olkuska, Pomeranian, and Polish Pogórza sheep was evaluated. Diameter, coefficient of variation, comfort and prickle factors, % of medullated fibers, heat resistance, and absorption were evaluated. It was shown that the breeds differed in diameter and heat resistance. No differences were shown between the absorption properties of the wool. This research has shown that the wool characteristic with the greatest variation is its diameter. Understanding the properties of the wool of local breeds will allow it to be better managed, instead of treating it as waste.

Brigita Tomšič, Maja Blagojevič, Nuša Klančar et al.

In this study, a novel green process was developed to produce a multifunctional cotton (CO) fabric incorporating TiO2/curcumin composites that simultaneously provides UV protection and photocatalytic performance. For this purpose, TiO2 was synthesised using the sol–gel process; loaded with the natural colourant curcumin as a visible light absorber at two temperatures, i.e., 70 and 350 °C; and applied to the CO fabric via the pad–dry–cure process. For comparison, TiO2 was synthesised without curcumin under the same conditions. The synthesis conditions at 70 °C ensured the formation of predominantly amorphous TiO2, while curcumin promoted TiO2 crystallisation despite the low synthesis temperature. A 350 °C synthesis temperature was high enough to form the polymorphic TiO2 anatase phase. Although the increase in synthesis temperature and the presence of curcumin in the composites caused a bathochromic shift in light absorption, the photocatalytic activity of all samples was mainly driven by UV light. Chemically modifying the CO fabric significantly reduced the light transmittance of the samples, with the highest absorption of UV light obtained for the sample containing the TiO2/curcumin composite synthesised at 70 °C. This sample provided excellent UV protection with a UPF value of 51.6. All chemically modified CO samples showed photocatalytic activity, degrading coffee stains and decolourising methylene blue and Rhodamine B dye solutions. The highest photocatalytic efficiency and recyclability were obtained again for the CO sample with the TiO2/curcumin composite synthesised at 70 °C, demonstrating the synergistic effect between TiO2 and curcumin in the composite prepared under these synthesis conditions.

Ming Chen, Hong Cui, Zhipeng Shen

Abstract This study investigates the influence of spinning process parameters on microfiber release from polyester fabrics, identifying yarn hairiness as the dominant controlling factor. Experimental results demonstrate an extremely high correlation (R 2 = 0.997) between 3 mm hairiness and microfiber release, confirming protruding fibers as the primary shedding source. Among the parameters examined, spinning method exhibits greater influence than twist factor, with Siro compact spinning consistently delivering optimal performance by achieving minimal hairiness and microfiber release while maintaining high breaking strength. The optimal combination was determined as Siro compact spinning with a twist factor of 400. The research establishes that spinning method's effect on microfiber release is primarily indirect, mediated through its determination of yarn hairiness. These findings provide a scientific basis for source reduction of microplastic pollution in textiles, demonstrating that proper selection of spinning technologies and process parameters can significantly reduce microfiber shedding at the manufacturing stage. The study offers practical solutions for developing more sustainable textiles and advancing green manufacturing practices in the textile industry, contributing to environmental protection and circular economy objectives.

Leona Holloway, Kim Marriott, Matthew Butler et al.

The difficulty and consequent fear of travel is one of the most disabling consequences of blindness and severe vision impairment, affecting confidence and quality of life. Traditional tactile graphics are vital in the Orientation and Mobility training process, however 3D printing may have the capacity to enable production of more meaningful and inclusive maps. This study explored the use of 3D printed maps on site at a public event to examine their suitability and to identify guidelines for the design of future 3D maps. An iterative design process was used in the production of the 3D maps, with feedback from visitors who are blind or have low vision informing the recommendations for their design and use. For example, it was found that many representational 3D icons could be recognised by touch without the need for a key and that such a map helped form mental models of the event space. Complex maps, however, require time to explore and should be made available before an event or at the entrance in a comfortable position. The maps were found to support the orientation and mobility process, and importantly to also promote a positive message about inclusion and accessibility.

Spyridon Besias, Ilias Sertaridis, Florentia Afentaki et al.

Printed Electronics (PE) provide a mechanically flexible and cost-effective solution for machine learning (ML) circuits, compared to silicon-based technologies. However, due to large feature sizes, printed classifiers are limited by high power, area, and energy overheads, which restricts the realization of battery-powered systems. In this work, we design sequential printed bespoke Support Vector Machine (SVM) circuits that adhere to the power constraints of existing printed batteries while minimizing energy consumption, thereby boosting battery life. Our results show 6.5x energy savings while maintaining higher accuracy compared to the state of the art.

Burkhard C. Schipper, Tina Danting Zhang

We study dynamic decentralized two-sided matching in which players may encounter unanticipated experiences. As they become aware of these experiences, they may change their preferences over players on the other side of the market. Consequently, they may get ``divorced'' and rematch again with other agents, which may lead to further unanticipated experiences etc. A matching is stable if there is absence of pairwise common belief in blocking. Stable matchings can be destabilized by unanticipated experiences. Yet, we show that there exist self-confirming outcomes that are stable and do not lead to further unanticipated experiences. We introduce a natural decentralized matching process that, at each period assigns probability $1 - \varepsilon$ to the satisfaction of a mutual optimal blocking pair (if it exists) and picks any optimal blocking pair otherwise. The parameter $\varepsilon$ is interpreted as a friction of the matching market. We show that for any decentralized matching process, frictions are necessary for convergence to stability even without unawareness. Our process converges to self-confirming stable outcomes. Further, we allow for bilateral communication/flirting that changes the awareness and say that a matching is flirt-proof stable if there is absence of communication leading to pairwise common belief in blocking. We show that our natural decentralized matching process converges to flirt-proof self-confirming outcomes.

Silvana A. Caipa Cure, Daniela J. Kraft

Simulations on self-propelling active cubes reveal interesting behaviors at both the individual and the collective level, emphasizing the importance of developing experimental analogs that allow to test these theoretical predictions. The majority of experimental realizations of active colloidal cubes rely on light actuation and or magnetic fields to have a persistent active mechanism, and lack material versatility. Here we propose a system of active bimetallic cubes whose propulsion mechanism is based on a catalytic reaction and study their behavior. We realize such a system from synthetic silica cuboids and 3D printed micro cubes, followed by the deposition of gold and platinum layers on their surface. We characterize the colloids dynamics for different thicknesses of the gold layer at low and high hydrogen peroxide concentrations. We show that the thickness of the base gold layer has only a minor effect on the self propulsion speed and in addition induces a gravitational torque which leads to particles with a velocity director pointing out of the plane thus effectively suppressing propulsion. We find that a higher active force can remedy the effects of torque, resulting in particle orientations that are favorable for in plane propulsion. Finally, we use 3D printing to compare our results to cubes made from a different material, size and roundness, and demonstrate that the speed scaling with increasing particle size originates from the size-dependent drag. Our experiments extend fabrication of active cubes to different materials and propulsion mechanisms and highlight that the design of active particles with anisotropic shapes requires consideration of the interplay between the shape and activity to achieve favorable sedimentation and efficient in plane propulsion.

Yumeng Wu, George Chiu

This paper proposes an improved model of height profile for drop-on-demand printing of UV curable ink. Unlike previous model, the proposed model propagates volume and covered area based on height difference between adjacent drops. Height profile is then calculated from the propagated volume and area. Measurements of 2-drop and 3-drop patterns are used to experimentally compute model parameters. The parameters are used to predict and validate height profiles of 4 and more drops in a straight line. Using the same root mean square (RMS) error as benchmark, this model achieves 5.9% RMS height profile error on 4-drop lines. This represents more than 60% reduction from graph-based model and an improvement from our previous effort.

André Flores, Amanda Albertin, Rafael de Avila Delucis et al.

Physical and mechanical performance of natural fiber composites can be tailored by hybridizing with synthetic fibers. Jute fibers are promising and highly available at a low cost in some countries, and they have been used in several applications, with the extra benefit of helping socially depressed people who commonly explore this plant. This work investigates the effect of hybridization on the properties of jute/glass and jute/carbon laminates with polyester resin. Nine different laminates were manufactured by vacuum infusion using unidirectional jute, E-glass, and carbon fabric reinforcements. Tensile, flexural, and short beam tests were performed in accordance with ASTM standards. The hybrid composites showed generally intermediate properties compared to the non-hybrid two-component laminates. The mechanical properties of the hybrid composites were 50–75% smaller than those of their respective pure glass and pure carbon composites, but 30–300% higher compared to the pure jute composite. Among the hybrids, the number of layers of the synthetic fiber played the most important role on properties, rather than the layup. That is, the variation in the number of jute fabrics may produce the required combination of stiffness and strength for different applications. Besides, the hybrid laminates, with more layers of synthetic fibers showed better hygroscopic performance.

Melese Getachew, Tesfaye Gabriel, Anteneh Belete et al.

Teff (Eragrostis tef), a grass which belongs to the Family Poaceae, is widely cultivated for its starch-rich grains in Ethiopia, generating large amounts of agricultural byproduct, teff straw. The aim of this study was to isolate and characterize cellulose and microcrystalline cellulose (MCC) from teff straw and evaluate MCC as directly compressible tablet excipient. Cellulose was extracted from teff straw and partially depolymerized to obtain MCC. The physicochemical properties of cellulose and MCC powders were characterized. Yields of cellulose and MCC powder from the raw material were 35.2% and 27.2%, respectively. The samples exhibited type-I crystal lattice and similar infrared spectra with that of Avicel PH-101. The degree of polymerization (DP) and crystallinity index of cellulose were 594.51 and 72.26%, respectively. Whereas, MCC powders showed DP of 241.09–257.38 and crystallinity indexes of 76.45–84.52%. Spray dried MCC was found to be more porous and poorly flowable and had higher moisture content when compared with the oven-dried MCC powder. Tablets prepared from both MCC powders fulfil most of the pharmacopoeial requirements. The spray-dried MCC powder also showed superior compactibility to oven-dried MCC. Teff straw can, therefore, be considered to be an alternative source of cellulose and MCC.

Argyris Kokkinis, Georgios Zervakis, Kostas Siozios et al.

The demand of many application domains for flexibility, stretchability, and porosity cannot be typically met by the silicon VLSI technologies. Printed Electronics (PE) has been introduced as a candidate solution that can satisfy those requirements and enable the integration of smart devices on consumer goods at ultra low-cost enabling also in situ and ondemand fabrication. However, the large features sizes in PE constraint those efforts and prohibit the design of complex ML circuits due to area and power limitations. Though, classification is mainly the core task in printed applications. In this work, we examine, for the first time, the impact of neural minimization techniques, in conjunction with bespoke circuit implementations, on the area-efficiency of printed Multilayer Perceptron classifiers. Results show that for up to 5% accuracy loss up to 8x area reduction can be achieved.

Giorgos Armeniakos, Georgios Zervakis, Dimitrios Soudris et al.

Printed Electronics (PE) exhibits on-demand, extremely low-cost hardware due to its additive manufacturing process, enabling machine learning (ML) applications for domains that feature ultra-low cost, conformity, and non-toxicity requirements that silicon-based systems cannot deliver. Nevertheless, large feature sizes in PE prohibit the realization of complex printed ML circuits. In this work, we present, for the first time, an automated printed-aware software/hardware co-design framework that exploits approximate computing principles to enable ultra-resource constrained printed multilayer perceptrons (MLPs). Our evaluation demonstrates that, compared to the state-of-the-art baseline, our circuits feature on average 6x (5.7x) lower area (power) and less than 1% accuracy loss.

Alireza Ahmadianyazdi, Isaac J. Miller, Albert Folch

Stereolithographic 3D-printing (SLA) permits facile fabrication of high-precision microfluidic and lab-on-a-chip devices. SLA photopolymers often yield parts with low mechanical compliancy in sharp contrast to elastomers such as poly(dimethyl siloxane) (PDMS). On the other hand, SLA-printable elastomers with soft mechanical properties do not fulfill the distinct requirements for a highly manufacturable resin in microfluidics (e.g., high-resolution printability, transparency, low-viscosity). These limitations restrict our ability to print microfluidic actuators containing dynamic, movable elements. Here we introduce low-viscous photopolymers based on a tunable blend of poly(ethylene glycol) diacrylate (PEGDA, Mw~258) and poly(ethylene glycol methyl ether) methacrylate (PEGMEMA, Mw~300) monomers. In these blends, which we term PEGDA-co-PEGMEMA, tuning the PEGMEMA-to-PEGDA ratio alters the elastic modulus of the printed plastics by ~400-fold, reaching that of PDMS. Through the addition of PEGMEMA, moreover, PEGDA-co-PEGMEMA retains desirable properties of highly manufacturable PEGDA such as low viscosity, solvent compatibility, cytocompatibility and low drug absorptivity. With PEGDA-co-PEGMEMA, we SLA-printed drastically enhanced fluidic actuators including microvalves, micropumps, and microregulators with a hybrid structure containing a flexible PEGDA-co-PEGMEMA membrane within a rigid PEGDA housing. These components were built using a custom "Print-Pause-Print" protocol, referred to as "3P-printing", that allows for fabricating high-resolution multimaterial parts with a desktop SLA printer without the need for post-assembly. SLA-printing of multimaterial microfluidic actuators addresses the unmet need of high-performance on-chip controls in 3D-printed microfluidic and lab-on-a-chip devices.

Recep Karadag

Rahel Krause, Justin Kühn, Thomas Gries et al.

In order to better protect emergency personnel, a suitable material was sought that would meet various requirements. To achieve this, a project was carried out by the Saxon Textile Research Institute e. V. (STFI), Germany and the Institut für Textiltechnik (ITA) of RWTH Aachen University, Germany, called “Molotov cocktail protection – protective clothing material for emergency forces”. First, suitable fiber mixtures were selected and then tested for a high accuracy of fit. Afterwards, specially designed fabrics were developed and produced to realize a smooth surface. In addition, a coating for high hydrophobia was established. To examine these newly developed fabrics, a test procedure was developed and modified. Results show correlations between fiber selection as well as yarn and fabric construction with the resulting fabric properties. Findings can be given in the form of technological and product-related recommendations.

Bemgba B. Nyakuma, Olagoke Oladokun, Ezekiel B. Ogunbode et al.

In this study, natural fibers were extracted from Imperata cylindrica (ICY) by mechanical fractionation followed by characterization. The morphological, microstructural, and thermal properties of ICY fibers were examined by scanning electron microscopy (SEM), energy-dispersive X-ray, and thermal gravimetric analysis (TGA). Kinetic analysis was examined through Flynn Wall Ozawa (FWO) and Kissinger Akahira Sunose (KAS) models. Results showed that mechanical fractionation successfully extracted natural fibers from ICY. SEM analyses revealed a compact surface structure interrupted by contours and protrusions due to disoriented fractionation of the fibers. Thermal analysis revealed significant mass loss (72.94–77.03%), whereas the TG/DTG plots shifted correspondingly due to multiple heating rates (10–30°C/min) and thermal lag during TGA from 30 to 800°C. Likewise, the onset, midpoint, offset, drying, and devolatilization peak temperatures increased at higher heating rates. Tons increased from 257.99–269.25°C, whereas Tmid was 313.57–319.17°C, Toff was 363.70–376.58°C. The OFW and KAS kinetic models revealed activation energy (Ea) and frequency factor (ko) ranged from 38.09 to 514.33 kJ mol−1 and 1.65 × 1002 to 1.24 × 1048 min−1, respectively, for conversions α = 0.05 to 0.95, which indicate ICY fibers are thermally stable and suitable for utilization as bio-composite reinforcement.

Abdullah Sayam, Fogla Rabbi, Mohammad Hossain et al.

With the surging demand for versatile products with eclectic fabric construction, weaving industries often qualify the standardized denting order with a view to utilize the reeds that are at their disposal. In the weaving cycle, beat-up operation is performed by reed which also controls the denting order. The appearance and quality of woven fabric vary due to various parameters. Among them denting order is one of the most overlooked parameters. The present study is uniquely designed to determine the ramifications of the denting order changing on plain woven fabric quality and appearance while keeping the loom parameters, yarn parameters and fabric construction constant. A total of five plain fabrics were manufactured and six performance properties including tear resistance, tensile strength, seam slippage resistance, fabric weight, abrasion and pilling resistance of the samples were analyzed and statistically evaluated with ANOVA. The appearance was assessed visually. What appeared was that tensile, tear, and appearance had undergone perpetual change for all the samples but change of seam slippage, fabric weight, abrasion, and pilling resistance remained inconsistent. Statistical evaluation also revealed that the difference among the fabric properties due to variation of denting order were significant especially for tearing and tensile strength.

Islam Imranul, Khan Nazmul Hassan, Islam Atiqul et al.

In terms of sustainability & wearing comfort, denim manufacturers are entering a new era of product variety. Tencel's regenerative nature and unique mechanical qualities usher in a new era for the denim industry. In this work, denim fabrics were manufactured using Tencel Cotton blended yarn using very fi ne yarn (20 Tex or 30 Ne), and fabric performance was examined following factors like tensile strength and other relevant metrics. For better evaluation, All the structures were 2/1 RHT (right-hand twill) that contained 115 EPI & 70 PPI and also indigo blue dyed. According to the result of the investigation, 100% Tencel Fabric (both the warp and the weft yarn were 100% Tencel) demonstrated the highest quality of fabric performance in terms of tensile strength, tearing strength, stiff ness, air permeability, and water vapor permeability than any other cotton or cotton Tencel blended fabric. However, a downward trend of abrasion resistance was observed in Tencel or cotton Tencel blended fabric concerning the percentage change of Tencel. Additionally, the performance of the fabric was significantly improved by the percentage addition of Tencel fiber in the warp and weft directions. In addition, a denim fabric made entirely of cotton performed the least well when compared to fabrics made entirely of Tencel or a blend of Tencel and cotton.