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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Desenvolvimento de antena CPW em substrato têxtil em estrutura de malha para utilização em sistemas de indentificação por rádio frequência

Oliveira, Alexandre Henrique Soares de 07 April 2017 (has links)
Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-07-10T22:31:35Z No. of bitstreams: 1 AlexandreHSO_DISSERT.pdf: 4241907 bytes, checksum: 7c578927aa89afb44e48b7e51e99d120 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-18T15:08:29Z (GMT) No. of bitstreams: 1 AlexandreHSO_DISSERT.pdf: 4241907 bytes, checksum: 7c578927aa89afb44e48b7e51e99d120 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-18T15:08:46Z (GMT) No. of bitstreams: 1 AlexandreHSO_DISSERT.pdf: 4241907 bytes, checksum: 7c578927aa89afb44e48b7e51e99d120 (MD5) / Made available in DSpace on 2017-07-18T15:09:43Z (GMT). No. of bitstreams: 1 AlexandreHSO_DISSERT.pdf: 4241907 bytes, checksum: 7c578927aa89afb44e48b7e51e99d120 (MD5) Previous issue date: 2017-04-07 / Fundação de Apoio à Pesquisa do RN / The knitted fabrics have elastic, easy production and malleability properties, these characteristics be useful in the design of flexible antennas, that can be used in a RFID tag, for example. The mean objective of this work is development of antenna with a Coplanar Waveguide fed (CPW), in a textile knitted substrate, for use in active RFID systems in microwave frequency of 2.45 GHz. From the characterization of the electrical properties by a Vector Networks Analyzer and one with a Dielectric Probe kit, obtained the values of Electrical Permissiveness and Loss Tangent, in sequence was carried out the characterization of the textile properties of Linear Density, Basis weight, Dimensional stability and Tensile Strength, based on the data obtained in characterization process, was chosen two fabrics with properties favorable to the design, modeling and construction of antennas. After the selection of the tissues, simulations were performed on Ansys HFSStm (High Frequency Structural Simulator) to obtain the parameters of Return Loss, Radiation Diagram, Current Density, Impedance, Gain and VSWR, as well as dimensional optimization of the antennas. Two CPW-fed antennas were simulated, one on textile substrate made from Soybean Protein Fibers (SPF) and the other with Polypropylene with corn Polylactic Acid fibers (PP + PLA). Based on the simulations, two antennas with their respective textile substrates were constructed and using a vector network analyzer, the return loss and the impedance shown by the Smith Chart were measured. Both showed a return loss below -10dB for central design frequency and wide bandwidth. The simulated and measured results were compared, analyzing them according to the specialized reading in the area. Showing the feasibility of developing CPW antennas in knitted fabrics for active RFID systems, in addition to the possibility of interoperability in internet of things (IoT) communication systems / Os tecidos de malha apresentam propriedades de elasticidade, facilidade de fabricação e maleabilidade, devido a estas características a utilização desse tipo de tecido traz vantagens na fabricação de antenas para aplicação no desenvolvimento de uma tag RFID. O presente trabalho tem como objetivo desenvolver antenas com guias de ondas coplanares (CPW), em substrato têxtil em estruturas de malha, para utilização em sistemas ativos de Identificação por Rádio Frequência, RFID, para frequência de operação em micro-ondas de 2,45 GHz. Foi realizada a caracterização das propriedades elétricas por meio de um Analisador de Redes Vetoriais e com uma sonda de medição de matérias dielétricos, obtive-se então os valores de Permissividade elétrica e Tangentes de perdas, em sequência foi realizada a caracterização das propriedades têxteis de Título, Gramatura, Estabilidade Dimensional e Resistência a tração, com base nos dados obtidos no processo de caracterização se elegeu dois tecidos com propriedades favoráveis ao projeto, modelagem e construção das antenas têxteis. Após a seleção dos tecidos foram feitas simulações no Ansys HFSS® (High Frequency Strucutural Simulator) para obtenção dos parâmetros de Perda de retorno, Diagrama de radiação, Densidade de corrente, Impedância, Ganho e VSWR, além da otimização dimensional das antenas. Foram simuladas duas antenas CPW, uma em substrato têxtil feito de fibras de Proteína de Soja (SPF) e outra com fibras de Polipropileno com Ácido Polilático de Milho (PP+PLA). Com base nas simulações foram construídas duas antenas com os respectivos substratos têxteis e utilizando um analisador de redes vetoriais foram medidos a perda de retorno e a impedância, mostrada por meio da Carta de Smith. Ambas apresentaram uma perda de retorno abaixo de -10 dB para frequência central de projeto e uma alta largura de banda. Foi realizada a comparação dos resultados simulados e os efetivamente medidos, analisando-os de acordo com a literatura especializada na área. Mostrando a viabilidade do desenvolvimento de antenas CPW em tecidos de malha para sistemas RFID ativos, além da possibilidade da interoperabilidade em sistemas de comunicação por Internet das coisas, Internet of Things, IoT / 2017-07-10
22

Influência dos parâmetros de regulagem de máquina nas características físicas de malhas de poliamida/elastano / Influence of machine parameters on the physical properties of polyamide/elastane single jersey fabrics

Fernando Barros de Vasconcelos 14 December 2012 (has links)
O comportamento dinamométrico de malhas submetidas à tração é geralmente inadequado para atender aos padrões atuais de conforto e desempenho e, portanto, fibras elastoméricas são cada vez mais utilizadas em conjunto com algodão, viscose, poliamida e poliéster para conferir aos artigos um maior grau de alongamento e uma melhor recuperação elástica. Dessa forma as características desses produtos estão amplamente associadas ao fio de elastano e sua utilização. No entanto as relações entre a proporção de elastano, a alimentação de fio rígido e as propriedades físicas obtidas nas malhas é algo ainda pouco estudado. O objetivo desse trabalho é estudar e definir essas relações através do planejamento de experimentos em malhas monofrontura de poliamida/elastano. Foram alteradas condições de alimentação do fio de poliamida (LFA) e tensão do elastano e, após relaxamento, medidas várias propriedades das malhas produzidas como gramatura, largura, densidade, espessura, porcentagem de elastano, permeabilidade ao vapor, alongamento e elasticidade. Foi possível observar como a tensão de elastano é preponderante na densidade e na porcentagem de elastano, enquanto o LFA da poliamida é predominante na espessura e alongamento da malha, enquanto a largura, a elasticidade e a permeabilidade ao vapor não sofrem influências significativas de nenhum dos dois fatores analisados. / The dynamometric behavior of knits subjected to traction is generally inadequate to meet current standards of comfort and performance and, therefore, elastomeric fibers are increasingly used in combination with cotton, viscose, polyamide and polyester to give to these articles a greater degree of elongation and better elastic recovery. Thus the characteristics of these products are widely associated with elastane yarn. However the relationship between the elastic yarn rate, the loop length and the physical properties obtained in the jersey knit is somewhat poorly studied. The aim of this work is to study and define these relationships using design of experiments in polyamide / elastane single jersey knits. The polyamide feed (LFA) and elastane tension were changed and, after relaxation, measurements of jersey properties were done, such as mass per unit area, width, density, thickness, percentage of elastane, water vapor permeability, elongation and elasticity. It was possible to observe how elastane tension is leading to density and percentage of spandex, while polyamide LFA is predominant in the thickness and elongation, since the width, elasticity and vapor permeability are not influenced by either of the two significant factors
23

Élaboration de texticaments à visée antiinflammatoire contenant des microcapsules respectueuses de l’environnement / Elaboration of anti-inflammatory textiles based on eco-friendly microcapsules

Dao, Thi Chinh Thuy 08 February 2018 (has links)
L'utilisation des microcapsules fabriquées à partir de matériaux respectueux de l'environnement pour des applications textiles médicales a été étudiée et développée fortement au cours des dernières années. Le but de cette thèse est d'élaborer les textiles anti-inflammatoires à base de microcapsules respectueuses de l'environnement, utilisant trois types de matériaux textiles (coton, peco 65/35 et polyester) et cinq niveaux de longueur de boucle (2.81, 2.83, 2.87, 2,96 et 3,05 mm) sur étoffes tricotées à verrouillage de coton (nombre de fils Ne40). Les influences de la concentration en saponine, de la vitesse d'agitation au cours de l'étape d'émulsification et du volume d'éthyle acétate ajouté à la phase aqueuse sur les caractéristiques des microcapsules ont été étudiées. L'étude a également étudié les effets du rapport massique du coton et de la longueur de boucle des étoffes tricotées sur la distribution des microcapsules, la capacité de chargement des microcapsules et la capacité de libération de l'ibuprofène des étoffes tricotées traités par microcapsules. Les microcapsules d'Eudragit RSPO contenant de l'ibuprofène ont été élaborées par la technique d'évaporation de solvant, en utilisant le tensioactif bio-sourcé quillaja saponine et le solvant non halogéné d'éthyle acétate. Les microcapsules obtenues présentaient les formes sphériques avec un diamètre d (0,5) de 21,5 μm, approprié pour les applications textiles. Il a été trouvé que, pour empêcher la déformation des microcapsules pendant la traitement du textile, la séchage doit être effectuée sous vide à 45 ° C. Lorsque le rapport de teneur en fibres de coton dans le tissu augmentait, la distribution des microcapsules était moins régulière, ce qui entraînait un taux de libération plus faible de l'ibuprofène à partir des étoffes tricotées traités aux microcapsules. En outre, lorsque la longueur de la boucle augmente, la capacité de chargement des microcapsules des étoffes tricotées traités augmente, la distribution des microcapsules sur le tissu devient moins régulière et la vitesse de libération de l'ibuprofène des tissus traités aux microcapsules diminue. De plus, l'augmentation de l'extension du étoffes tricotées a favorisé la libération d'ibuprofène à partir des étoffes tricotées traités par les microcapsules à travers la peau de porc / The use of the microcapsules made from eco-friendly materials for medical textile applications has been researched and developed strongly in recent years. The aim of this thesis is to elaborate the anti-inflammatory textiles basing on eco-friendly microcapsules,using three kinds of textile materials (cotton, peco 65/35 and polyester)and five levels of the loop length (2.81, 2.83, 2.87, 2.96 and 3.05 mm) on the cotton interlock knitted fabrics (yarn count Ne40). The influences of the saponin concentration, the stirring rate during the emulsification step and the volume of ethyl acetate added to the aqueous phase on the characteristics of the microcapsules were studied. The influence of condition in drying on microcapsule’s morphology was also investigated.The thesis also researched the effects of cotton mass ratio and loop length of fabric on the microcapsule distribution, the microcapsule loading capability and the release capability of ibuprofen from the microcapsule treated fabrics. The Eudragit RSPO microcapsules containing ibuprofen were successfully elaborated by solvent evaporation technique, using the bio-sourced surfactant quillajasaponin and the non-halogenated solvent ethyl acetate. The obtained microcapsules exhibited the spherical shapes with d(0.5) diameter of 21.5 m, suitable for the textile applications. It was found that in order to keep the microcapsules from deformation during the textile finishing, the drying stage should be carried out in vacuum at 45oC. When the content ratio of cotton fibers in the fabric increased,the microcapsule distribution was less even, resulting in the lower release rate of ibuprofen from the microcapsule-treated fabrics. Besides, when the loop length increased, the microcapsule loading capability of the treated fabrics increased, the microcapsule distribution on the fabric became less even and the release rate of ibuprofen from the microcapsule-treated fabrics decreased. Furthermore, increasing the fabric extension favored the release of ibuprofen from the microcapsule-treated fabrics through the pigskin
24

Knitted Circuits for Visual and Tactile Interactive Expressions

Persson, Anna January 2009 (has links)
As computational technology and new materials are entering the world of textiles, our view on the textile material is challenged; the areas of textiledesign and interaction design start to merge. Designing interactive textiles means communicating new expressional forms through textile material. This thesis aim to contribute to the exploration of designing interactive knitted textiles with focus on linking interactive properties, especially visual and tactile, to different ways of expressing them. Design examples and experiments presented are meant to show new possibilities for designing textile material able to change structure, colour and temperaturein different ways in response to environmental stimuli. As a way of presenting, and reflecting on, these interactive properties, a notion of expression diagrams is introduced. / <p>Photographs on pages 36, 37, 40, by Lars Hallnäs.</p><p>Other photographs by the authors and participants in the projects.</p>
25

Thermal textile pixels : Out-of-plane and in-plane heat transfer measurements of knitted textiles

Stöhr, Adriana January 2019 (has links)
The human body possesses a highly developed range of senses that help orienting oneself in everyday life. Especially when it comes to navigating, perceiving and reacting to the world around us, people tend to rely mostly on their vision and hearing. Suffering from an impairment of either one, or both of the predominating senses means having to counterbalance this constraint. People suffering from blindness and deaf-blindness compensate their impairment mainly by relying on their haptic perception. In this case, information is usually communicated by braille or vibrotactile means. To offer another non-visual and non-audial communication concept this thesis work introduces, the thermal textile pixels. A thermal textile pixel consists of an external thermal device, able to generate hot and cold thermal impulses, and a textile interface to transmit the signal. In order to design such thermal textile pixel it was crucial to be aware of the thermal transfer occurring through and within an textile. Numerous research studies have examined the thermal properties of textiles, especially in the context of clothing comfort, thermal comfort. Nevertheless, it should be considered that as a thermal textile pixel, the textile forms part of a system, governed by many parameters. Therefore, for designing such a device it is important to be aware of the temporal and spatial resolution of the thermal transmitted signal. These characteristics are influenced by multiple textile parameters. For this purpose, a thermal study has been performed investigating in- and out-of-plane signal transmission by textiles in combination with an external thermal device. Using an external thermal device such as a Peltier element allowed to expose the specimens to heating as well as to active cooling. Different knitted structures and material combinations have been examined to gain a first impression on the behaviour of thermal pixels. It was found that thickness and density were the most influential factors for out-of-plane heat transfer. In-plane was found influenced mainly by fibre conductivity. An anisotropic behaviour was noted in-plane, as well as between in- and out-of-plane for heat transfer. Investigating active cooling signals, it was found that a significant decline of performance was noted for all specimens. Plain PA was found to be most suitable for the transmission of heat signals. But did not perform equally well during active cooling phases. Plain Shieldex was observed to perform most steady during heating and active cooling.
26

Development of multiaxial warp knitting technology for production of three-dimensional near net shape shell preforms

Sankaran, Vignaesh, Rittner, Steffen, Hahn, Lars, Cherif, Chokri 05 November 2019 (has links)
The possibility of direct preforming in the near net shape of final component structure with load- and shape-conforming fiber orientations is highly essential in composite production, not only to reduce costs but also to attain better mechanical properties and form stability. Based on the concept of varying the reinforcement yarn lengths during the feed-in (warp yarn delivery) and segmented doffing, synchronous working numerically controlled warp yarn delivery and doffing machine modules have been newly developed for multiaxial warp knitting machines to create a resource efficient textile process chain by a single-step, large-scale oriented production of load- and form-conforming warp knitted three-dimensional shell preforms with free-form geometrical surfaces. Such customized preforms in the near component net shape offer higher material utilization and increased lightweight potential.
27

Solblockerande textilier : Optimering av solskydd

Brobeck, Caroline, Westblom, Elin January 2018 (has links)
extilindustrin måste ständigt söka nya alternativ inom beläggningar och laminering för att minska den skadliga miljöpåverkan. En fråga som uppkommit är om beläggningar används i större utsträckning än vad som egentligen behövs. Denna kandidatuppsats har skrivits i samarbete med Artex AB och kretsar kring ett befintligt solskydd och solens ljusspektrum som består av strålar mellan 320–2500 nm. Material som bestrålas kan antingen absorbera, reflektera eller transmittera dessa strålar. Strålarnas alternativa vägar adderat med varandra blir alltid hundra procent, vilket innebär att genom att öka den reflekterande förmågan minskas de andra två tillstånden. I denna studie granskas den totala reflekterande förmågan av ljusspektrumet hos textila material som i sin tur beror på många olika faktorer. Det undersöks även om det är ett steg i fel riktning att använda sig av beläggningar för att nå ett bättre högreflekterande material. Detta även för att minska miljöbelastningen. Eftersom beläggningar generellt förstyvar material är detta kontraproduktivt när man vill bibehålla följsamheten hos en tygvara, vilket är avgörande för denna typ av produkt. Skrynkelheten går nämligen hand i hand med tygvarans då stumma yta. Detta projekt fokuserar på solskydd som ska användas inifrån en bil. Syftet med studien var alltså att undersöka om en obelagd vit och tät tygvara kan uppnå tillräcklig funktion för ett solskydd innanför en bil. I experimenten användes fyra olika tygvaror med olika strukturer i bindningarna för att göra en så omfattande studie som möjligt. Dessa fyra var: en satin, en varptrikå och två stycken tvåskaft, varav den ena glesare och mer matt än den andra. Respektive tygvara beströks med ett färgpigment för att analysera om kombinationen mellan reflektion och elastisk potential var möjlig. Tester som genomförts i denna undersökning var: bestämning av färghärdighet, total reflektion, ljustransmittansmätning och ett egenkomponerat skrynkeltest. Vidare granskades dess skillnader för att undersöka om ett vitt material kunde ge en bättre totalreflektion, men även för att bevisa att en tygvaras konstruktion kan erhålla följsamheten även om en beläggning är nödvändig. Mätvärdena granskades för att sedan jämföra, först med varandra och sedan mot ett referensprov som kommer från en befintlig produkt som författarna fick att tillgå från Artex AB. En trikåvaras elastiska förmåga visade sig kunna bibehållas trots ett belagt ytskikt, och visade även på bra totalreflektion. Denna varptrikå uppvisade, tillsammans med satinen, på bra totalreflektion då de var obelagda och hade god följsamhet. I test om totalreflektion visades det att en vit tät tygvara reflekterade större procent än en belagd tygvara i det synliga ljusets spektrum. För att kunna dra slutsatser om ett vitt obelagt tyg med dessa konstruktioner (satin och varptrikå) hade varit bättre för ett solskydd hade vidare undrsökningar behövts göras. Detta för att se hur mycket av den totala reaktionen som är diffus respektive spekulär / The textile industry must always find ways to reinvent itself and look for alternative options, as the coating and lamination industries are vital for a better environment. A question that needs answering is if coating on textiles are used more than needed. This bachelor thesis is written in cooperation with Artex AB and revolves around the suns light spectrum that consists of rays of 320 to 2500 nm. Materials that irradiate can either absorb, reflect or transmit these wavelengths. The rays alternative routes added with each other is always one hundred percent, which means that through increasing the reflecting capacity the other two will decrease. The most interesting part of this study, was to examine the ability of the light spectrum for material, and take in to consideration it’s construction, structure and color. Textile materials are often coated to add qualities and, in this case, to increase reflecting quality. This study is trying to prove, that it's a step in the wrong direction when it comes to the functionality of a sunshade product and for a reduced impact on the environment. As coating generally stiffens materials it’s contuerproductive with regards to keeping the resilience for the fabric, which is decisive for this type of product. The wrinkles go hand in hand with the fabrics coated surface. Since this project focuses on an existing sunshade product that will be used inside of a car, the heat radiation and the undulations within a certain wavelength that requires reflection will be focused on. The purpose with the study was to examine if an uncoated white fabric can achieve the same function in a sunshade as the current fabric in the product. In the experiments, four fabrics with different structures were used to complete such a comprehensive study as possible. These four fabrics were: one satin, one warp knitted and two plain weave, where one of them was more faint and sparse than the other. Each fabric was coated with a color pigment to analyze the possibilities of a high reflective material that still has elastic potential. The tests that were made was: determination of color fastness, total reflection, light transmit and a wrinkle test. Further on these differences were reviewed, and then concluded that the coating, in hope of increasing the reflection, is negligible. But also, to prove that a fabrics construction can keep its resilience even with a coated surface. These values have been reviewed and then compared with each other and against a reference fabric that the writers took part of from Artex AB. A warp knitted fabric was able to maintain its elastic ability regardless of a coated surface, and also shows good total reflection. This warp knitted fabric showed, together with the satin, good total reflection when they were uncoated and had good resilience. In this test for total reflection, it was proven that a white dense fabric reflects better than a coated fabric in the visible spectra of light. To be able to conclude if a white uncoated fabric with these constructions (satin and warp knitting) would be more useful for a sunshade, further studies had to be made, to see how much of the total reaction that is diffuse and specular.
28

Elektronické komponenty v textilních substrátech / Electronic Components in Textile Substrates

Kokolia, Martin January 2022 (has links)
Cílem této práce je popsat současný stav v oblasti mikrovlnných komponent na bázi textilu a poté také autorův příspěvek k výzkumu. V tomto studijním oboru je třeba řešit mnoho problémů, a proto jsou stanoveny velmi konkrétní cíle, které by měly tvořit kompletní komunikační systém, který by byl snadno integrovatelný do čalounění uvnitř letadla nebo jiného vozidla. První kapitola je zaměřena na použití relativně nízkofrekvenčních obvodů v pásmu UHF a vysokofrekvenční sklízení energie. Po simulacích následují praktická měření. Další kapitola charakterizuje nové 3D pletené textilie a jejich vysokofrekveční vlastnosti a modelování na velmi vysokých frekvencích, které jsou žádoucí pro užití jako komunikační kanály. S prakticky ověřeným a numericky popsaným textilním substrátem pro použití v pásmu SHF je představena nový vlnovod integrovaný do textilu na bázi tisknutelného umělého magnetického vodiče s praktickou metodikou návrhu. Po ověření byl vlnovod použit pro základní dělič výkonu, dvě různé antény a dva typy senzorů. Všechny návrhy byly vyrobeny a testovány s uspokojivými výsledky.
29

Modelización de la variación dimensional de los tejidos de punto por recogida durante todo el proceso productivo

Llinares Berenguer, Jorge Óscar 24 October 2022 (has links)
Tesis por compendio / [ES] El objetivo de esta tesis se considera de gran relevancia para los técnicos de las industrias textiles de género de punto, ya que contribuye a simplificar enormemente los cálculos productivos en las empresas de género de punto por trama. Ofrece un método eficaz para predecir el encogimiento longitudinal, transversal y al ancho de los tejidos de punto después de los procesos de tejeduría, tintura y acabados a partir de la forma dimensional que adopte la malla. Esta investigación se ha realizado con el análisis de más de 700 muestras de tejido extraídas de sus respectivas partidas de tejido. Con este análisis se han obtenido modelos de regresión lineal. Después de la verificación de los resultados obtenidos se validan los modelos, apreciando mínimos errores que verifican su aplicabilidad. Esta Tesis Doctoral comienza con el análisis de la variación dimensional de las tres estructuras fundamentales: interlock, 1x1 rib y single jersey. Durante los procesos de tejeduría, tintura y acabado de los tejidos de punto, se pueden dar una serie de circunstancias que pueden alterar la calidad del producto final del tejido y por consiguiente su transmisión directa al artículo al que va a ser destinado. Uno de estos factores que ha creado mucha incertidumbre en su trabajo a los técnicos de las industrias textiles ha sido la estabilidad dimensional de los tejidos de punto. La aplicación de los resultados de la Tesis puede proporcionar un importante ahorro de tiempo a las empresas de género de punto y, en consecuencia, un ahorro de inversión en stock de productos intermedios. Con la aplicación de los modelos desarrollados, las empresas no necesitan utilizar los métodos de cálculo comunes consistentes en la aplicación de la norma UNE EN ISO 6330-2012, que requiere un día de parada en la producción hasta la obtención de los resultados. También en esta tesis doctoral se han propuesto modelos que expliquen la variabilidad de la longitud del hilo absorbido por una malla, en cada una de las tres estructuras fundamentales, a partir de modelos que utilizan otras variables mucho más sencillas de analizar. De esta forma se deja de un lado el cálculo tradicional utilizado basado en la norma UNE-EN 14970, ya que este procedimiento es algo engorroso, requiriendo mucho tiempo y un aparato de medición del hilo. Con la utilización de los modelos propuestos se agiliza la estimación de la longitud de malla entre los estados de relajación propuestos, dos en tejeduría (Tejeduría y relajación en seco y Tejeduría y relajación en húmedo) y dos en tintura (Tintura y relajación en seco y tintura y relajación en húmedo). / [CA] L'objectiu d'aquesta tesi es considera de gran rellevància per als tècnics de les indústries tèxtils de gènere de punt, ja que contribueix a simplificar enormement els càlculs productius a les empreses de gènere de punt per trama. Ofereix un mètode eficaç per predir l'encongiment longitudinal i transversal dels teixits de punt després dels processos de teixidura, tintura i acabats a partir de la forma dimensional que adopte la malla. Aquesta investigació s'ha fet amb l'anàlisi de més de 700 mostres de teixit extretes de les respectives partides de teixit. Amb aquesta anàlisi s'han obtingut models de regressió lineal. Després de la verificació dels resultats obtinguts es validen els models, apreciant mínims errors que verifiquen la seua aplicabilitat. Aquesta Tesi Doctoral comença amb l'anàlisi de la variació dimensional de les tres estructures fonamentals: interlock, 1x1 rib i single jersei. Durant els processos de teixidura, tintura i acabat dels teixits de punt, es poden donar una sèrie de circumstàncies que poden alterar la qualitat del producte final del teixit i per tant la seva transmissió directa a l'article a què serà destinat. Un d'aquests factors que ha creat molta incertesa a la feina als tècnics de les indústries tèxtils ha estat l'estabilitat dimensional dels teixits de punt. L'aplicació dels resultats de la Tesi pot proporcionar un important estalvi de temps a les empreses de gènere de punt i, en conseqüència, un estalvi d'inversió en estoc de productes intermedis. Amb l'aplicació dels models desenvolupats, les empreses no necessiten utilitzar els mètodes de càlcul comuns consistents en l'aplicació de la norma UNE EN ISO 6330-2012, que requereix un dia de parada a la producció fins a l'obtenció dels resultats. També en aquesta tesi doctoral s'han proposat models que expliquen la variabilitat de la longitud del fil absorbit per una malla, en cadascuna de les tres estructures fonamentals, a partir de models que utilitzen altres variables molt més senzilles d'analitzar. D'aquesta manera es deixa d'una banda el càlcul tradicional utilitzat basat en la norma UNE-EN 14970, ja que aquest procediment és una mica molest, requerint molt de temps i un aparell de mesura del fil. Amb la utilització dels models proposats s'agilitza l'estimació de la longitud de malla entre els estats de relaxació proposats, dos en teixidura (Teixidura i relaxació en sec i Teixidura i relaxació en humit) i dos en tintura (Tintura i relaxació en sec i tintura i relaxació en humit). / [EN] The objective of this thesis is considered of great relevance for the technical of the knitwear textile industries, since it greatly simplifies the productive calculations in weft knitting companies. It offers an effective method for predicting the longitudinal and transverse shrinkage of knitted fabrics after the knitting, dyeing and finishing processes, based on the dimensional shape adopted by the loop. This research has been carried out with the analysis of more than 700 knitting samples extracted from their respective fabrics items. With this analysis we have obtained linear regression models. After verification of the results obtained, the models are validated, appreciating minimum errors that verify their applicability. This Doctoral Thesis begins with the analysis of the dimensional variation of the three fundamental structures: interlock, 1x1 rib and single jersey. During the knitting, dyeing and finishing processes of knitted fabrics, can be given a series of circumstances that can alter the quality of the final product of the fabric and therefore its direct transmission to the article to which it is going to be intended. One of these factors that has created a lot of uncertainty in your work technical of the textile industries has been the dimensional stability of knitted fabrics. The application of the results of the Thesis can provide a significant save time for knitting companies and, consequently, an investment savings in stock of intermediate products. With the application of developed models, companies do not need to use the calculation methods consisting of the application of the UNE EN ISO 6330-2012 standard, which It requires a day of stoppage in production until the results are obtained. Also in this doctoral thesis models have been proposed that explain the variability of the length of the thread absorbed by a loop, in each of the three fundamental structures, from models that use other variables much easier to analyze. In this way, it leaves aside the traditional calculation used based on the UNE-EN 14970 standard, since this procedure is somewhat cumbersome, requiring a lot of time and a thread measurement. With the use of the proposed models, the estimation of the loop length between the proposed relaxation states, two in knitting (knitting and dry relaxation and knitting and wet relaxation) and two in dyeing (dyeing and dry relaxation and dyeing and wet relaxation). / Llinares Berenguer, JÓ. (2022). Modelización de la variación dimensional de los tejidos de punto por recogida durante todo el proceso productivo [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/188844 / Compendio
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Development of temperature sensing fabric

Husain, Muhammad Dawood January 2012 (has links)
Human body temperature is an important indicator of physical performance and condition in terms of comfort, heat or cold stress. The aim of this research was to develop Temperature Sensing Fabric (TSF) for continuous temperature measurement in healthcare applications. The study covers the development and manufacture of TSF by embedding fine metallic wire into the structure of textile material using a commercial computerised knitting machine. The operational principle of TSF is based on the inherent propensity of a metal wire to respond to changes in temperature with variation in its electrical resistance. Over 60 TSF samples were developed with combinations of different sensing elements, two inlay densities and highly textured polyester yarn as the base material. TSF samples were created using either bare or insulated wires with a range of diameters from 50 to 150 μm and metal wires of nickel, copper, tungsten, and nickel coated copper. In order to investigate the Temperature-Resistance (T-R) relationship of TSF samples for calibration purposes, a customised test rig was developed and monitoring software was created in the LabVIEW environment, to record the temperature and resistance signals simultaneously. TSF samples were tested in various thermal environments, under laboratory conditions and in practical wear trials, to analyse the relationship between the temperature and resistance of the sensing fabric and to develop base line specifications such as sensitivity, resistance ratio, precision, nominal resistance, and response time; the influence of external parameters such as humidity and strain were also monitored. The regression uncertainty was found to be less than in ±0.1°C; the repeatability uncertainty was found to be less than ±0.5°C; the manufacturing uncertainty in terms of nominal resistance was found to be ± 2% from its mean. The experimental T-R relationship of TSF was validated by modelling in the thermo-electrical domain in both steady and transient states. A maximum error of 0.2°C was found between the experimental and modelled T-R relationships. TSF samples made with bare wire sensing elements showed slight variations in their resistance during strain tests, however, samples made with insulated sensing elements did not demonstrate any detectable strain-dependent-resistance error. The overall thermal response of TSF was found to be affected by basal fabric thickness and mass; the effect of RH was not found to be significant. TSF samples with higher-resistance sensing elements performed better than lower-resistance types. Furthermore, TSF samples made using insulated wire were more straightforward to manufacture because of their increased tensile strength and exhibited better sensing performance than samples made with bare wire. In all the human body wear trials, under steady-state and dynamic conditions both sensors followed the same trends and exhibited similar movement artifacts. When layers of clothing were worn over the sensors, the difference between the response of the TSF and a high-precision reference temperature were reduced by the improved isothermal conditions near the measurement site.

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