The thesis deals with the development of piezoresistive materials. Its objective is to investigate a system formed of a knitted fabric to be used as a piezoresistive sensor that allows electrical behaviour to be interrelated based on the elongation applied. Simultaneously, the correlation between elastic deformation and that caused by applying pressure by detecting the area where the pressure is produced will also be studied. For this purpose, knitted fabrics will be used and conductive textiles will be added to them. A testing method will be designed and the properties of the fabric will be evaluated. As a result, a smart textile will be obtained. / La tesis versa sobre el desarrollo de materiales piezoresistivos. Como objetivo se plantea la investigación de un sistema compuesto por un tejido de punto para ser utilizado como sensor piezoresistivo que permita relacionar el comportamiento eléctrico en función del a elongación aplicada. Paralelamente también se estudiará la correlación entre la deformación elástica y la ocasionada al aplicar una presión detectando la zona donde se produce la presión. Para ello se utilizarán tejidos de punto y se les incorporarán textiles conductores. Se diseñará un método de ensayo y se evalúan las propiedades de los tejidos. Como resultado final se obtendrá un textil inteligente. / La tesi versa sobre el desenvolupament de materials piezoresistius. Com a objectiu es planteja la investigació d'un sistema compost per un teixit de punt per a ser utilitzat com a sensor piezoresistiu que permeta relacionar el comportament elèctric en funció de l'elongació aplicada. Paral·lelament, també s'estudiarà la correlació entre la deformació elàstica i l'ocasionada a l'aplicar una pressió i la detecció de la zona on es produeix la pressió. Per a dur-ho a terme s'utilitzaran teixits de punt als quals s'incorporaran tèxtils conductors. Es dissenyarà un mètode d'assaig i s'avaluaran les propietats dels teixits. Com a resultat final, s'obtindrà un tèxtil intel·ligent. / Cambra Sánchez, V. (2017). ESTUDIO DE LA RESPUESTA ELÉCTRICA DE TEJIDOS PIEZORESISTIVOS SOMETIDOS A ESTIRAMIENTO Y DEFORMACIÓN POR PRESIÓN [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90404 / TESIS

Propone un modelo de prevención de riesgos disergonómicos en un taller de confecciones para reducir los sobreesfuerzos en los trabajadores mejorando su salud y permanencia en la empresa, para no incurrir en costos innecesarios. Para su efecto, primero, se analizan las condiciones de seguridad de todo el taller en función de una lista de identificación inicial de riesgos y un cuestionario, realizado a todos los trabajadores, que permite tener el diagnóstico de la situación. Luego se identifica los puestos de trabajo más inseguros haciendo uso de la matriz de riesgos, clasificada por actividades, que luego será evaluada, mediante los métodos ergonómicos Check-List OCRA y REBA, que permiten realizar un análisis específico para cada parte del cuerpo, teniendo como resultados riesgos inaceptables, con un nivel de actuación inmediata. Por tal motivo, se proponen medidas correctivas y preventivas que mejoran la interacción del operario con su entorno. Por último, la propuesta es evaluada ergonómica y económicamente para justificar la factibilidad de la inversión, se concluye que el modelo de prevención de riesgos disergonómicos es rentable para un taller de confecciones, porque el valor del Tasa Interna de Retorno es mayor que el costo de oportunidad actual del negocio. Y asimismo el Valor Actual Neto es positivo, lo cual permite ser considerado como una gran opción de inversión para los accionistas. / Tesis

Lors des procédés de fabrication des matériaux composites de type «RTM» (Resin Transfer Moulding) des résines sont injectées au travers du renfort préalablement mis en forme. La maîtrise de la mise en forme du renfort sec dans le moule est essentielle pour la maîtrise des défauts. De nombreuses études couvrent des domaines très larges associés à cette étape pour les renforts tissés, alors que peu de travaux ont porté sur la déformabilité des renforts tricotés lors de cette phase de préformage, malgré leur grande extensibilité et leur potentialité en tant que renforts de matériaux composites. Le comportement macroscopique des textiles techniques est essentiellement dû à un effet de structure. Dans le cadre de ces travaux sont détaillés l'élaboration et la conception de renforts tricotés afin de bien comprendre les paramètres spécifiques à ces structures textiles. Puis une étude expérimentale du comportement mécanique est conduite en traction uni axiale. Au travers de l'utilisation de méthodes de mesure des déformations sans contact l'analyse du comportement dans le sens colonnes et rangées est menée. Associé à la détermination du comportement, des essais de préformage de renforts secs tricotés sont réalisés sur un banc spécifique. L'analyse des résultats en termes d'avalement, d'efforts d'emboutissages et des déformations dans le fil montre la spécificité de la déformabilité de ces structures, comparativement aux renforts tissés. En vue de qualifier la faisabilité de cette étape de mise en forme de ces renforts tricotés, une corrélation entre le comportement en traction et le comportement lors du procédé est proposée. / During the manufacturing process of composite materials, such as «RTM» (Resin Transfer Moulding); resin is injected through the preformed reinforcement. The mastery of dry reinforcement layout in the mold is essential for defects control. Many studies cover wide areas related to this step for woven reinforcements, while few studies have focused on the deformability of knitted reinforcements at forming stage in spite of their significant extensibility and their potential as reinforcements of composite materials. The macroscopic behavior of the technical textiles is mainly due to their structural effect. In this research, the development and detailed design of knitted reinforcements in order to understand the specific parameters as textile structures are carried out. An experimental study of the uniaxial tensile mechanical behavior is conducted. The mechanical behavior of knitted structures in different orientations is analyzed by using contactless deformation measurements. In association with the characterization of in-plan behavior, forming tests of dry knitted reinforcements are performed on a special rig. Analysis of the results in terms of shortening, forming forces and local deformations shows the specificity of the deformability of these structures compared with woven reinforcements. To describe the formability of the knitted reinforcements, a correlation between the tensile and forming behavior is given.

Les maladies cardiovasculaires sont les premières causes de mortalités dans le monde. La manière la plus efficace de combattre ces maladies est le suivi en temps réel de l’électrocardiogramme (ECG) qui traduit les signaux électriques générés par les cellules cardiaques. Le signal ECG fournit aux cardiologues toutes les informations nécessaires pour diagnostiquer les pathologies cardiaques. De nos jours, l’électrocardiogramme s’enregistre en cabinet à l’aide d’électrodes cutanées à base d’argent et chlorure de l’argent (Ag/AgCl). Celles-ci ne sont pas conçues pour un usage prolongé et peuvent provoquer des irritations de la peau à cause du gel ionique qui les compose et qui sert à réduire l’impédance de l’interface électrode/peau. Dans cette thèse, des électrodes textiles flexibles fonctionnant sans aucun gel ionique ont été développées en tant qu’alternatives aux électrodes médicales (Ag/AgCl). Notre approche est basée sur la modification d’encres conductrices à base du polymère intrinsèquement conducteur, le poly (3,4-éthylènedioxythiophène) poly(styrènesulfonate) (PEDOT:PSS) compatible avec les substrats textiles choisis. La réalisation des électrodes fait appel à des techniques de fabrication qui peuvent être transférées facilement à l’industrie textile. Des caractérisations ont été mises en places afin d’évaluer la fiabilité de ces systèmes avant et après 50 lavages en machine de laboratoire et domestique. En l’occurrence, la résistivité surfacique des électrodes-capteurs, la modélisation de l’interface électrode/peau, l’analyse du signal ECG en statique et en dynamique, la densité spectrale de puissance du signal ECG, le rapport signal sur bruit (SNR) ont été analysés et comparés à des électrodes commerciales à base d’argent. Comme nos électrodes-capteurs développées possèdent un véritable potentiel clinique et industriel, nous avons également étudié la faisabilité de la connectique et sa durabilité. La solution retenue se compose de deux fils conducteurs en polyamide argenté, existants sur le marché, brodés pour réaliser les connexions entre les électrodes-capteurs textiles et un module électronique flexible à base d’un film composite (polyester-aluminium). De plus deux méthodes d’encapsulation des systèmes ont été également développées en vue de leur protection au lavage et futur commercialisation. / Cardiovascular diseases are the leading cause of death worldwide. The most effective way to combat these diseases is the real-time monitoring of the electrocardiogram (ECG) that reflect the electrical signals generated by the heart cells. The ECG signal provides to cardiologists all the information needed to diagnose heart diseases. So far, the electrocardiogram is recorded by using the cutaneous conventional medical electrodes (Ag/AgCl) based on silver and silver chloride. These electrodes are not destined for long-term use and can provoke skin irritation because of the ionic gel that serves to reduce the impedance of the electrode / skin interface. In this thesis, flexible textile electrodes operating without any ionic gel have been developed as alternatives to medical electrodes (Ag/AgCl). Our approach is based on the modification of conductive inks based on the intrinsically conductive polymer, poly (3,4-ethylenedioxythiophene) poly (styrenesulfonate) (PEDOT: PSS) compatible with selected textile substrates. The realization of the electrodes uses manufacturing techniques that can be easily transferred to the textile industry. Characterizations were set up to evaluate the reliability of these systems before and after 50 washes in laboratory and domestic machines. In this case, the surface resistivity of the electrodes-sensors, the modeling of the electrode/skin interface, the analysis of the ECG signal in static and dynamic, the spectral power density of the ECG signal, the signal-to-noise ratio (SNR) were analyzed and compared to commercial silver-based electrodes. As our developed sensor electrodes have a real clinical and industrial potential, we have also studied the feasibility of the connection and its durability. The chosen solution consists of two silver-plated polyamide threads, which are available on the market, embroidered to make the connections between the textile sensor electrodes and a flexible electronic module based on a composite film (polyester-aluminum). In addition, two encapsulation methods have also been developed to protect systems during washing and to make them ready for the market.

Weaving and architecture, conceived simultaneously with cave paintings, are two ancient forms of craft used to enclose space and provide shelter harmoniously with nature. In its basic composition, a useable textile is the interlacing of two members, warp and weft, at right angles to create structure and surface respectively. Textile artist Anni Albers of the Bauhaus attributes the organization of weaving to the skills of an ancient goddess. Her understanding of prehistoric cultures further links women closer to the overall creation of structure, though perceived as a masculine endeavor. Consequently, early advancements in architecture, the structural organization of shelter, are a result of feminine inventions. Moreover, it has been the female who has been entrusted with emotional and sensual elements of shelter since prehistory. Through the creation of a home, woman’s mastery of the domestic realm strengthened and led to gender-defining ideologies. Suburban typologies of the post-war United States heightened the feminine domestic role through social and environmental isolation of the gender. The suburbs ironically conditioned an alternative sentiment of the built environment featuring ideals of tradition, sustenance, and continuity with nature. In the modern era, weaving and architecture have devolved to be similarly designed and chosen for aesthetic qualities only. Textiles are produced for an indoor existence with weaving traditions unchanged and innovation seen in synthetic fibers. Modern shelter is chosen and constructed using inefficient practices popularized in the 1950s, with advancements only in materiality. Both disciplines overlook their feminine link and mutual advantages of protection, flexibility, user connection, tactile engagement, and environmental impact. As a result of this disregard, the capacity of the planet suffers due to outdated and unsustainable residential building practices, while quality of life degrades due to the inabilities of built spaces to nurture and engage inhabitants effectively. Based on eco-maternalist philosophies within architecture and the structural, spatial, and tactile qualities of weaving, these crafts can again interlock into a modern, efficient construction of shelter. The time has come to rethink building design and the feminine integration of weaver and architect provides a foundation for the discovery of an appropriate assembly for the next generation.

Expone la utilización de la metodología de mejora continua Six Sigma para la mejora de procesos en una empresa textil exportadora, la cual se desarrolló en base a la metodología de cinco fases DMAMC (definir, medir, analizar, mejorar y controlar), con el objetivo de reducir la cantidad de tela no conforme y calificada internamente como no exportable, así como mejorar los principales indicadores de gestión de calidad establecidos por la empresa en estudio. / Tesis

Today's medical textile market is producing state of the art polymeric textile implantable devices that are redefining traditional materials and methods of surgery. These sophisticated high-tech polymer materials are engineered for specific uses in surgical and interventional procedures. One of the new biotextile products is an absorbable bi-directional barbed surgical suture that does not require surgical knots for wound closure. This novel idea has the attention of many physicians and surgeons where wound closure or tissue approximation is needed. The barbed suture has the potential to change the way wound closure is perceived in various clinical fields of surgery and veterinary medicine.

Thermomechanical recycling of polyethylene terephthalate (PET) typically includes a decrease in the polymer´s intrinsic viscosity and therefore a reduction of the molecular weight. Consequently, thermomechanical recycling is usually a downcycling of the product. However current methods to increase the molecular weight such as solid-state polymerization or the usage of chain extenders are time consuming or introduce foreign molecules into the PET´s molecular chain. Thus, the aim of this work was to try to increase the molecular weight in the molten state in an extruder, to decrease the processing times. The processing times are reduced compared to the solid-state polymerization because in the molten state the movability of the polymer chain is increased. Moreover, no supplementary substances are added for the processing so that no foreign structures are introduced during reprocessing. Virgin PET pellets were extruded at 285°C, 290°C and 295°C set temperature and 2rpm, 4rpm, and 7rpm screw rotation rate. Afterwards the PET´s properties were investigated by measuring their intrinsic viscosities, conducting a 1H NMR and a DSC measurement. Additionally, pre-experiments were conducted to explore the possibilities of feeding industrial scrap polyester fabrics into the extruder. The polymer characterization showed that the intrinsic viscosity and therefore the molecular weight of the processed samples decreased with the parameters chosen for this experiment. Samples processed at 285°C and 7 rpm showed in the average the highest intrinsic viscosities and therefore the highest molecular weight of all processed samples. Additionally, the results of the 1H NMR and the DSC indicated degradation reactions such as thermal degradation and hydrolysis. Thus, further research is necessary to find an easily accessible recycling method for polyester textiles and reduce the amount of polyester textile waste. However, it is possible to feed long textile stripes into the twin screw extruder and reprocess it to a strand which is an important step for further recycling.

Abarca la problemática de la Micro y Pequeña Empresa (MYPE) de confecciones, donde existen particularidades como su forma de organización realizada de manera empírica y la visión cortoplacista. De acuerdo con el Instituto Nacional de Calidad - INACAL (2018), Lima y Callao concentran el 66% de MYPE de manufactura; además, existen diversos centros de formación académica y capacitación técnica. Sin embargo, la mayoría de los empresarios no consideran la capacitación dentro de sus prioridades. En consecuencia, los emprendimientos se acrecientan cada año, situación que no sucede con la profesionalización de las empresas generando escasez de organizaciones competitivas, principalmente en el segmento de la micro y pequeña empresa. Se plantea como objetivo principal mejorar la competitividad de la MYPE de confecciones, mediante una metodología denominada Gestión Integral. Esta propuesta consiste en implementar secuencialmente herramientas de gestión para mejorar la toma de decisiones; la información obtenida se basa en datos provenientes de los procesos estratégicos y operativos de una empresa seleccionada, la aplicación involucra sincronizar la estrategia de negocio a los procesos por lo que se realizan cambios graduales en la estructura de la empresa y en la forma de realizar sus actividades. / Tesis

No description available.