1,721,001 research outputs found
Green whitening of polyester fabric using fluorescent brightener OB-1 in a mixture of water and decamethylcyclopentasiloxane media /
No full textFluorescent brightening agent OB-1 (OB-1) is often used in plastic goods because of its non-toxic nature, chemical stability, remarkable heat resistance, and light stability. Raw OB-1 is challenging to use in textiles using the exhaustion method. This study used a novel method using raw OB-1 powder to whiten polyester fabric in water and decamethylcyclopentasiloxane (D5). The Taguchi approach investigated the interaction between whitening process parameters such as temperature, OB-1 mass, water: D5 ratio, and treatment time with four levels. The study shows that the temperature and water: D5 ratio during the whitening process significantly affect the whiteness of polyester fabric (P < 0.05), with contribution percentages of 74.2 % and 25.2 %. Subsequently, various analytical techniques were employed, including FTIR, SEM, TGA, and XRD, to characterise the whitened fabric. The findings imply that using water: D5 medium was effective in whitening polyester fabric without causing major alterations to the structure of the PET fabric. The study also examined the fastness of washing and crocking to determine their whitening stability. Overall, polyester fabric whitened with water and D5 medium exhibited satisfactory whitening performance and might be a potential scope for use on a larger scale in developing the sustainable textile industry
Elektrai laidžios šildomos ir kompresinės tektilės kūrimas.
No full textThe PhD work presents a study carried out on electronic textiles for heat generation in compressive weft-knitted fabrics used for orthopaedic compression supports. The aim of this investigation was to develop compressive knitted structures with joule heating function and to investigate their heat generation characteristics and temperature changes under stretch and dependent on wearing requirements. A flat double needle-bed knitting machine was used to fabricate the developed specimens with elastomeric inlay-yarn, incorporated into the structure for compression generation, and silver coated polyamide yarn laid as ground yarn in a plated structure for heat generation. The problem associated with rigid elements used in the existing orthopaedic support has been solved in this study to avoid changes in the compression. The upscaling and industrial use of such supports are feasible, as long as several technological steps for structure fabrication are solved, including wearing conditions. The temperature profile of the structures and the comparison of the heat generation by the samples after stretching and washing at different levels were studied. The findings revealed that all fabrics heated up quickly for the first minute and afterwards this rising slowdown. Finally, the heating levelled off at 40-45°C within 2-3 minutes with some exception depending on applied voltage and conductive yarn used in the knitting pattern. This behaviour of the fabric is very suitable for heat therapy. Washing and stretching negatively influence heat generation. Utilization of heavy power source has also been solved. Based on the research results, the prototype of the orthopaedic compressive heating support was produced
Heating profile of electro-conductive weft-knitted composite fabrics during cyclic deformation
No full textThe goal of this research was to learn more about how heat is generated during cyclic deformation of
highly conductive knitted composite fabric. The heating materials in this investigation were silver (Ag)
coated polyamide (PA) yarn knitted into a pattern. At various time intervals, the temperature generated
on the fabric surface was measured. An Instron tensile testing machine was used to perform the cyclic
stress strain in the course direction of the developed fabric. The temperature on the conductive fabric
surface increased rapidly for the first two minutes, then slowly afterward, eventually levelled off at a
specific point. Heat generation is negatively influenced by stretching and cyclic deformation. Heat
generation was also affected by the amount of conductive yarn used in the knitting design. The materials
developed in this work could be employed in orthopaedic compression support to offer sufficient
heating
Progress in flexible electronic textile for heating application: a critical review /
No full textIntelligent textiles are predicted to see a ‘surprising’ development in the future. The consequence of this revived interest has been the growth of industrial goods and the improvement of innovative methods for the incorporation of electrical features into textiles materials. Conductive textiles comprise conductive fibres, yarns, fabrics, and finished goods produced using them. Present perspectives to manufacture electrically conductive threads containing conductive substrates, metal wires, metallic yarns, and intrinsically conductive polymers. This analysis concentrates on the latest developments of electro-conductivity in the area of smart textiles and heeds especially to materials and their assembling processes. The aim of this work is to illustrate a potential trade-off between versatility, ergonomics, low energy utilization, integration, and heating properties
Preparation and characterization of handsheet using cellulose based agri-weed: a sustainable utilization of Urena lobata fiber /
No full textThe increasing depletion of reserves of natural resources has led to a growing worldwide focus on the exploitation of available waste in new domains. The presence of weedy plants is pervasive on a global scale and has detrimental effects on several aspects of the environment, agriculture, and people's health. Therefore, repurposing these Agri-weed plants for beneficial purposes would be a significant achievement. Furthermore, since raw materials constitute a substantial portion of manufacturing costs, using weeds as a feasible substitute for raw materials might potentially provide considerable advantages for manufacturers. In this study, an endeavor has been made to the utilization of agricultural waste “Urena Lobata”, for the purpose of paper production. In the interim, the utilization of Urena Lobata as an alternative and sustainable raw material for pulp and paper industry could potentially offer a beneficial approach to mitigation of deforestation. The effective production of handsheets with weights of 70 g/m2 and 80 g/m2 was achieved using Urena Lobata fiber, Bleached Urena Lobata Fiber, and hardwood kraft pulp. Mechanical characteristics of handsheet's were comprehensively examined by the bursting index, tensile strength, tear index, brightness percentage and scanning electron microscope for handsheet's morphology. The results show that the handsheets produced by Urena Lobata fiber exhibit a much lower brightness percentage, high tensile strength and bursting index. Alongside, handsheets by bleached Urena Lobata fiber indicate higher brightness percentage, satisfactory values for tensile strength, bursting index, and tear index. The prepared materials are suitable for a broad spectrum of prospective applications, encompassing newsprint, tissue paper, filtration paper as well as high-quality writing and printing paper
Synthetic dyes for textile colouration: process, factors and environmental impact /
No full textDyes are substances that enhance the appearance of finished goods by providing uniform colour. Dyeing is the application process of dyes that are fixed in textile fibers. The dyeing process uses various steps, including pretreatment, desizing, scouring, bleaching, carbonizing, degumming, and mercerization. Water is considered the primary medium for applying dyes and other chemicals for this treatment in the dyeing process. The dyeing process contains many toxic chemicals, metals and non-soluble substances, such as wastewater, which is thrown into the environment. It is noted that, during dyeing, around 50-300 liters of water is required for 1 kg of fiber. On the other hand, 1-2 million liters of water are needed every day for 50,000 meters of daily production. This massive amount of toxic wastewater is highly harmful to the environment, human health, aquatic system, soil, air, water, plants, and animals. This review paper states various dyeing processes with different dyes, including acid dye, direct dye, sulfur dye, reactive dye, vat dye, metal complex dye, azo dye, disperse dye, and basic dye. In contrast, it also describes the influencing factors of dyeing processes and methods. Moreover, this review demonstrates the impacts of textile dyes on the environment (water, soil, air emissions, human health) and illustrates possible remedial actions regarding wastewater
Enhancement of polyester dyeing performance integrating ecological and cost-effective auxiliaries /
No full textDisperse dyes, primarily used for dyeing synthetic fibres like polyester, are characterized by their poor solubility in water, which necessitates the use of dispersing agents; however, environmental concerns arise due to their low biodegradability and potential toxicity, thus posing significant challenges in waste management and pollution control. This study explores the dyeing performance of knitted polyester with dispersed dyes, employing natural auxiliaries as substitutes for conventional commercial chemicals to promote an environmentally friendly approach. Citric acid (derived from lemon), sodium citrate (prepared from citric acid and sodium bicarbonate), and glucose (extracted from date fruits) replace commercial acetic acid, dispersing agent, and hydrolyze. Dyeing is conducted using the high-temperature and high-pressure methods with consistent parameters. A comparative study of the dyeing performance of the natural auxiliaries with the existing commercial chemicals was assessed concerning colour strength, different fastness properties, and the FT-IR diagram. Proton NMR is utilized for the structural determination of date fruit and lemon components. UV-Vis spectral data show that adding sodium citrate to the dispersed dye solution drops the absorbance value from 1.1457 to 0.58916, confirming sodium citrate's efficacy as a dispersing agent. With lower recipe costs, the environmentally friendly approach using natural auxiliaries exhibits comparable dyeing performance and excellent fastness properties, providing a sustainable alternative to traditional methods
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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