Fabric handle properties of superfine wool fabrics with different fibre curvature, cashmere content and knitting tightness

The handle properties of single jersey fabrics composed of superfine wools (17 μm) of different fibre curvature (114 vs. 74 °/mm) in blends with cashmere (fibre curvature 49 °/mm) were investigated. There were four blend ratios of cashmere (0, 25, 50, 75%) plus 100% cashmere. Each of the nine fibre blend combinations were replicated three times, and each was knitted into three tightness factors. The 81 fabrics were evaluated using the Wool HandleMeter, which measures seven primary handle attributes and Overall handle, and have been calibrated using a panel of experts and a wide variety of commercial fabrics. Results were analysed by ANOVA and general linear modelling. Tightness factor significantly affected all Wool HandleMeter attribute values, with the effect of tightness factor varying according to handle attribute. The Wool HandleMeter was able to detect differences between fabrics composed of superfine wool differing in fibre curvature, with lower fibre curvature wool fabrics having more preferred Overall handle and softer, looser, cooler, lighter and less dry handle attributes at some or all tightness factors compared with fabrics composed of higher fibre curvature superfine wool. Progressively blending cashmere with wool significantly improved Overall handle, increased soft and smooth handle, reduced dry, heavy and tight handle. Linear regression modelling indicated that fabric mass per unit area explained more than 50% of the variance in overall fabric handle and in combination with variations in fabric thickness and yarn elongation could explain 71% of the variance in Overall handle.

Self-cleaning, superhydrophobic cotton fabrics with excellent washing durability, solvent resistance and chemical stability prepared from an SU-8 derived surface coating

Superhydrophobic cotton fabrics with a very low contact angle hysteresis were prepared using a single-pot coating solution comprising SU-8 (a negative photoresist), a fluorinated alkyl silane and silica nanoparticles. The fabric was treated using a dip-coating technique and subsequently cured under UV light. The coated fabric showed excellent superhydrophobicity with a water contact angle as high as 163° and a sliding angle as low as 2°. The coating was durable enough to withstand 100 laundry cycles. It also had excellent stability against long immersion times in organic solvents, and acid and base solutions.

Photochromic fabrics with improved optical performance

 Photochromism is a fascinating phenomenon which has attracted much commercial interest for applications including sunglasses, optical devices such as memories and switches, and security printing. Photochromic textile is an exciting new application due to its implications for fashion and UV protection. This book explores the phenomenon of photochromism, its application in textiles and ways of improving the performance and durability of photochromic fabrics.

Degradation of Acid Blue 40 dye solution and dye house wastewater from textile industry by photo-assisted electrochemical process

In this paper, electrochemical and photo-assisted electrochemical processes are used for color, total organic carbon (TOC) and chemical oxygen demand (COD) degradation of one of the most abundant and strongly colored industrial wastewaters, which results from the dyeing of fibers and fabrics in the textile industry. The experiments were carried out in an 18L pilot-scale tubular low reactor with 70% TiO2/30% RuO2 DSA. A synthetic acid blue 40 solution and real dye house wastewater, containing the same dye, were used for the experiments. By using current density of 80 mA cm(-2) electrochemical process has the capability to remove 80% of color, 46% of TOC and 69% of COD. When used the photochemical process with 4.6 mW cm(-2) of 254nm UV-C radiation to assist the electrolysis, has been obtained 90% of color, 64% of TOC and 60% of COD removal in 90 minutes of processing; furthermore, 70% of initial color was degraded within the first 15 minutes. Experimental runs using dye house wastewater resulted in 78% of color, 26% of TOC and 49% of COD in electrolysis at 80 mA cm(-2) and 90 min; additionally, when photo-assisted, electrolysis resulted in removals of 85% of color, 42% of TOC and 58% of COD. For the operational conditions used in this study, color, TOC and COD showed pseudo-first-order decaying profiles. Apparent rate constants for degradation of TOC and COD were improved by one order of magnitude when the photo-electrochemical process was used.

Multiscale analysis of the mechanical behavior of needle-punched nonwoven fabrics

Los fieltros son una familia de materiales textiles constituidos por una red desordenada de fibras conectadas por medio de enlaces térmicos, químicos o mecánicos. Presentan menor rigidez y resistencia (al igual que un menor coste de procesado) que sus homólogos tejidos, pero mayor deformabilidad y capacidad de absorción de energía. Los fieltros se emplean en diversas aplicaciones en ingeniería tales como aislamiento térmico, geotextiles, láminas ignífugas, filtración y absorción de agua, impacto balístico, etc. En particular, los fieltros punzonados fabricados con fibras de alta resistencia presentan una excelente resistencia frente a impacto balístico, ofreciendo las mismas prestaciones que los materiales tejidos con un tercio de la densidad areal. Sin embargo, se sabe muy poco acerca de los mecanismos de deformación y fallo a nivel microscópico, ni sobre como influyen en las propiedades mecánicas del material. Esta carencia de conocimiento dificulta la optimización del comportamiento mecánico de estos materiales y también limita el desarrollo de modelos constitutivos basados en mecanismos físicos, que puedan ser útiles en el diseño de componentes estructurales. En esta tesis doctoral se ha llevado a cabo un estudio minucioso con el fin de determinar los mecanismos de deformación y las propiedades mecánicas de fieltros punzonados fabricados con fibras de polietileno de ultra alto peso molecular. Los procesos de deformación y disipación de energía se han caracterizado en detalle por medio de una combinación de técnicas experimentales (ensayos mecánicos macroscópicos a velocidades de deformación cuasi-estáticas y dinámicas, impacto balístico, ensayos de extracción de una o múltiples fibras, microscopía óptica, tomografía computarizada de rayos X y difracción de rayos X de gran ángulo) que proporcionan información de los mecanismos dominantes a distintas escalas. Los ensayos mecánicos macroscópicos muestran que el fieltro presenta una resistencia y ductilidad excepcionales. El estado inicial de las fibras es curvado, y la carga se transmite por el fieltro a través de una red aleatoria e isótropa de nudos creada por el proceso de punzonamiento, resultando en la formación de una red activa de fibra. La rotación y el estirado de las fibras activas es seguido por el deslizamiento y extracción de la fibra de los puntos de anclaje mecánico. La mayor parte de la resistencia y la energía disipada es proporcionada por la extracción de las fibras activas de los nudos, y la fractura final tiene lugar como consecuencia del desenredo total de la red en una sección dada donde la deformación macroscópica se localiza. No obstante, aunque la distribución inicial de la orientación de las fibras es isótropa, las propiedades mecánicas resultantes (en términos de rigidez, resistencia y energía absorbida) son muy anisótropas. Los ensayos de extracción de múltiples fibras en diferentes orientaciones muestran que la estructura de los nudos conecta más fibras en la dirección transversal en comparación con la dirección de la máquina. La mejor interconectividad de las fibras a lo largo de la dirección transversal da lugar a una esqueleto activo de fibras más denso, mejorando las propiedades mecánicas. En términos de afinidad, los fieltros deformados a lo largo de la dirección transversal exhiben deformación afín (la deformación macroscópica transfiere directamente a las fibras por el material circundante), mientras que el fieltro deformado a lo largo de la dirección de la máquina presenta deformación no afín, y la mayor parte de la deformación macroscópica no es transmitida a las fibras. A partir de estas observaciones experimentales, se ha desarrollado un modelo constitutivo para fieltros punzonados confinados por enlaces mecánicos. El modelo considera los efectos de la deformación no afín, la conectividad anisótropa inducida durante el punzonamiento, la curvatura y re-orientación de la fibra, así como el desenredo y extracción de la fibra de los nudos. El modelo proporciona la respuesta de un mesodominio del material correspondiente al volumen asociado a un elemento finito, y se divide en dos bloques. El primer bloque representa el comportamiento de la red y establece la relación entre el gradiente de deformación macroscópico y la respuesta microscópica, obtenido a partir de la integración de la respuesta de las fibras en el mesodominio. El segundo bloque describe el comportamiento de la fibra, teniendo en cuenta las características de la deformación de cada familia de fibras en el mesodominio, incluyendo deformación no afín, estiramiento, deslizamiento y extracción. En la medida de lo posible, se ha asignado un significado físico claro a los parámetros del modelo, por lo que se pueden identificar por medio de ensayos independientes. Las simulaciones numéricas basadas en el modelo se adecúan a los resultados experimentales de ensayos cuasi-estáticos y balísticos desde el punto de vista de la respuesta mecánica macroscópica y de los micromecanismos de deformación. Además, suministran información adicional sobre la influencia de las características microstructurales (orientación de la fibra, conectividad de la fibra anisótropa, afinidad, etc) en el comportamiento mecánico de los fieltros punzonados. Nonwoven fabrics are a class of textile material made up of a disordered fiber network linked by either thermal, chemical or mechanical bonds. They present lower stiffness and strength (as well as processing cost) than the woven counterparts but much higher deformability and energy absorption capability and are used in many different engineering applications (including thermal insulation, geotextiles, fireproof layers, filtration and water absorption, ballistic impact, etc). In particular, needle-punched nonwoven fabrics manufactured with high strength fibers present an excellent performance for ballistic protection, providing the same ballistic protection with one third of the areal weight as compared to dry woven fabrics. Nevertheless, very little is known about their deformation and fracture micromechanisms at the microscopic level and how they contribute to the macroscopic mechanical properties. This lack of knowledge hinders the optimization of their mechanical performance and also limits the development of physically-based models of the mechanical behavior that can be used in the design of structural components with these materials. In this thesis, a thorough study was carried out to ascertain the micromechanisms of deformation and the mechanical properties of a needle-punched nonwoven fabric made up by ultra high molecular weight polyethylene fibers. The deformation and energy dissipation processes were characterized in detail by a combination of experimental techniques (macroscopic mechanical tests at quasi-static and high strain rates, ballistic impact, single fiber and multi fiber pull-out tests, optical microscopy, X-ray computed tomography and wide angle X-ray diffraction) that provided information of the dominant mechanisms at different length scales. The macroscopic mechanical tests showed that the nonwoven fabric presented an outstanding strength and energy absorption capacity. It was found that fibers were initially curved and the load was transferred within the fabric through the random and isotropic network of knots created by needlepunching, leading to the formation of an active fiber network. Uncurling and stretching of the active fibers was followed by fiber sliding and pull-out from the entanglement points. Most of the strength and energy dissipation was provided by the extraction of the active fibers from the knots and final fracture occurred by the total disentanglement of the fiber network in a given section at which the macroscopic deformation was localized. However, although the initial fiber orientation distribution was isotropic, the mechanical properties (in terms of stiffness, strength and energy absorption) were highly anisotropic. Pull-out tests of multiple fibers at different orientations showed that structure of the knots connected more fibers in the transverse direction as compared with the machine direction. The better fiber interconnection along the transverse direction led to a denser active fiber skeleton, enhancing the mechanical response. In terms of affinity, fabrics deformed along the transverse direction essentially displayed affine deformation {i.e. the macroscopic strain was directly transferred to the fibers by the surrounding fabric, while fabrics deformed along the machine direction underwent non-affine deformation, and most of the macroscopic strain was not transferred to the fibers. Based on these experimental observations, a constitutive model for the mechanical behavior of the mechanically-entangled nonwoven fiber network was developed. The model accounted for the effects of non-affine deformation, anisotropic connectivity induced by the entanglement points, fiber uncurling and re-orientation as well as fiber disentanglement and pull-out from the knots. The model provided the constitutive response for a mesodomain of the fabric corresponding to the volume associated to a finite element and is divided in two blocks. The first one was the network model which established the relationship between the macroscopic deformation gradient and the microscopic response obtained by integrating the response of the fibers in the mesodomain. The second one was the fiber model, which took into account the deformation features of each set of fibers in the mesodomain, including non-affinity, uncurling, pull-out and disentanglement. As far as possible, a clear physical meaning is given to the model parameters, so they can be identified by means of independent tests. The numerical simulations based on the model were in very good agreement with the experimental results of in-plane and ballistic mechanical response of the fabrics in terms of the macroscopic mechanical response and of the micromechanisms of deformation. In addition, it provided additional information about the influence of the microstructural features (fiber orientation, anisotropic fiber connectivity, affinity) on the mechanical performance of mechanically-entangled nonwoven fabrics.

Quilts, counterpanes and related printed fabrics /

Bibliography: p. [3] of cover.

Thermobonded Fabrics

In 2009 Avella created a series of innovative fabrics for the Yves St Laurent (YSL) collection, deploying techniques from vehicle engineering to generate new materials for a range of garments. Studying the bonding of layers of material in ceramic plate thermobonding technology, Avella conducted a series of experiments with textiles such as flannel, silk and synthetics, and material such as leather, layered with polyamide foam and textile substrate to create new, textured and insulating fabrics with beautiful surfaces and interesting forms. The lightweight properties of the foam enabled the maximum insulation/weight ratio, and the panel moulding technology brought new forms of draping prêt-a-porter fashion design. Exclusive to YSL, this technique was patented and then shown at the Premiere Vision textiles trade fair in 2010. Much documented in specialist journals this innovation also breached the trade-culture barrier and was reported and documented in mainstream newspapers (New York Herald Tribune). Avella’s background in textile workshop studio experimentation at the RCA brought to YSL textiles research for manufacture, the innovative collaboration between fashion couture and engineering laboratory experiments from vehicle design.

Photochromic fibers and fabrics

Photochromic fibers and fabrics can change color in response to light radiation. They represent a smart textile having attracted much attention recently and showing potential applications in diverse areas. This review chapter gives an overview of the state-of-the-art techniques for the preparation of photochromic fibers and fabrics. The properties and applications of photochromic fabrics are also discussed.

Directional water transport fabrics with durable ultra-high one-way transport capacity

Fabrics with automatic one-way water transport ability are highly desirable for applications in daily life, industry, health, and defense. However, most of the studies on one-way water transport fabrics only report the qualitative water transport results. The lack of quantitative measure makes it hard to assess the directional transport quality. Here, it is proved that a hydrophilic fabric after being electrosprayed with a thin layer of hydrophobic coating on one side shows one-way water transport ability. By using moisture management tester, the water transport property is qualitatively characterized and the effect of hydrophobic fabric layer thickness on one-way water transport feature is examined. The hydrophobic fabric layer thickness is found to play a key role in deciding the one-way transport ability. When a plain woven fabric with an overall thickness of 420 μm and average pore size of 33 μm is used as fabric substrate, a hydrophobic fabric layer thickness between 22 and 62 μm allows the treated fabric to show a one-way droplet transport feature. A one-way transport index as high as 861 can be attained. The one-way water transport is durable enough to withstand repeated washing. This novel fabric may be useful for development of “smart” textiles for various applications.

Protection of silica-coated ZnO nanoparticles on pre-dyed polyester fabrics against photofading

This work was designed to investigate the ability of silica-coated ZnO (ZnO&SiO2) nanoparticles (NPs) as ultraviolet (UV) absorbers for protecting pre-dyed polyester fabrics against photofading. Despite that ZnO NPs are excellent UV absorbers, their strong photocatalytic activity limits the application in UV protection. In this study, a silica layer was coated onto ZnO NPs to form a physical barrier between the ZnO and a polyester substrate, which allowed effective UV shielding while minimising the harmful effects of photocatalytic activity on the substrate. The structure and optical proprieties of ZnO&SiO2 NPs were observed. The bare ZnO and ZnO&SiO2 NPs were, respectively, applied to polyester fabrics coloured with three kinds of dyes by a dip coating method. The photofading level of treated fabrics after exposure under simulated sunlight was evaluated. The ZnO&SiO2 NPs exhibited excellent protection on pre-dyed polyester fabrics against photofading.

The power of a single prototype : sustainable fashion textile design and the prevention of carcinogenic melanoma

Is there a role for prototyping (sketching, pattern making and sampling) in addressing real world problems of sustainability (People, Profit, and Planet), in this case social/healthcare issues, through fashion and textiles research? Skin cancer and related illnesses are a major cause of disfigurement and death in New Zealand and Australia where the rates of Melanoma, a serious form of skin cancer, are four times higher than in the Northern Hemisphere regions of USA, UK and Canada (IARC, 1992). In 2007, AUT University (Auckland University of Technology) Fashion Department and the Health Promotion Department of Cancer Society - Auckland Division (CSA) developed a prototype hat aimed at exploring a barrier type solution to prevent facial and neck skin damage. This is a paradigm shift from the usual medical research model. This paper provides an overview of the project and examines how a fashion prototype has been used to communicate emergent social, environmental, personal, physiological and technological concerns to the trans-disciplinary research team. The authors consider how the design of a product can enhance and support sustainable design practice while contributing a potential solution to an ongoing health issue. Analysis of this case study provides an insight into prototyping in fashion and textiles design, user engagement and the importance of requirements analysis in relation to sustainable development. The analysis and a successful outcome of the final prototype have provided a gateway to future collaborative research and product development.