Electrospinning Processing Techniques for the Manufacturing of Composite Dielectric Elastomer Fibers

Dielectric elastomers (DE) are novel composite architectures capable of large actuation strains and the ability to be formed into a variety of actuator configurations. However, the high voltage requirement of DE actuators limits their applications for a variety of applications. Fiber actuators composed of DE fibers are particularly attractive as they can be formed into artificial muscle architectures. The interest in manufacturing micro or nanoscale DE fibers is increasing due to the possible applications in tissue engineering, filtration, drug delivery, catalysis, protective textiles, and sensors. Drawing, self-assembly, template-direct synthesis, and electrospinning processing have been explored to manufacture these fibers. Electrospinning has been proposed because of its ability to produce sub-mm diameter size fibers. In this paper, we investigate the impact of electrospinning parameters on the production of composite dielectric elastomer fibers. In an electrospinning setup, an electrostatic field is applied to a viscous polymer solution at an electrode’s tip. The polymer composite with carbon black and carbon nanotubes is expelled and accelerated towards a collector. Factors that are considered in this study include polymer concentration, solution viscosity, flow rate, electric field intensity, and the distance to the collector.

Flexible Theoretical Calculation of Loop Length and Area Density of Weft-Knitted Structures: Part II

A simple and flexible method for theoretical calculation of the main structural parameters of various weft-knitted fancy and combined patterns is presented in this article. It is especially important for patterns containing different elements, such as loops, floats of different lengths, tucks, and tuck stitches. Measurement of an actual average length of the loop in these fabrics is complicated because it is necessary to disassemble precisely one pattern repeat to measure the yarn length and divide it by the number of elements in this pattern repeat. For large and complex pattern repeats, this is difficult and usually gives a high number of errors. It is very important to have lengths of structural elements as it helps to predict the main physical properties of knitted fabrics and their mechanical behaviour, which is especially important for protective textiles. The main idea of the proposed method, based on Čiukas geometrical model, is to calculate lengths of various structural elements or even their parts separately, taking into account the number of needle bars and their formation principle, which gives great flexibility to such modelling. The proposed theoretical formulas can be used for various patterned weft-knitted structures containing not only loops but tucks, floats of different lengths, or additional yarns; they give very few errors in empirical calculations and are easy to use.

Using Artificial Neural Network Modeling to Analyze the Thermal Protective and Thermo-Physiological Comfort Performance of Textile Fabrics Used in Oilfield Workers’ Clothing

Most of the fatalities and injuries of oilfield workers result from inadequate protection and comfort by their clothing under various work hazards and ambient environments. Both the thermal protective performance and thermo-physiological comfort performance of textile fabrics used in clothing significantly contribute to the mitigation of workers’ skin burns and heat-stress-related deaths. This study aimed to apply the ANN modeling approach to analyze clothing performance considering the wearers’ sweat moisture and the microclimate air gap that is generated in between their body and clothing. Firstly, thermal protective and thermo-physiological comfort performance of fire protective textiles used in oilfield workers’ clothing were characterized. Different fabric properties (e.g., thickness, weight, fabric count), thermal protective performance, and thermo-physiological comfort performance were measured. The key fabric property that affects thermal protective and thermo-physiological performance was identified as thickness by statistical analysis. The ANN modeling approach could be successfully implemented to analyze the performance of fabrics in order to predict the performance more conveniently based on the fabric properties. It is expected that the developed models could inform on-duty oilfield workers about protective and thermo-physiological comfort performance and provide them with occupational health and safety.

Smart Textiles for Visible and IR Camouflage Application: State-of-the-Art and Microfabrication Path Forward

Protective textiles used for military applications must fulfill a variety of functional requirements, including durability, resistance to environmental conditions and ballistic threats, all while being comfortable and lightweight. In addition, these textiles must provide camouflage and concealment under various environmental conditions and, thus, a range of wavelengths on the electromagnetic spectrum. Similar requirements may exist for other applications, for instance hunting. With improvements in infrared sensing technology, the focus of protective textile research and development has shifted solely from providing visible camouflage to providing camouflage in the infrared (IR) region. Smart textiles, which can monitor and react to the textile wearer or environmental stimuli, have been applied to protective textiles to improve camouflage in the IR spectral range. This study presents a review of current smart textile technologies for visible and IR signature control of protective textiles, including coloration techniques, chromic materials, conductive polymers, and phase change materials. We propose novel fabrication technology combinations using various microfabrication techniques (e.g., three-dimensional (3D) printing; microfluidics; machine learning) to improve the visible and IR signature management of protective textiles and discuss possible challenges in terms of compatibility with the different textile performance requirements.

Anti viral Finishing on Texti les - An Overview

Antiviral textiles are one of the most promising areas of protective textiles. Antiviral textiles are important in the field of health and hygiene. They become an essential part of our daily-life when a pandemic situation arises. The present paper critically analyses and summarizes various researches of the production of antiviral textiles. Different classes of the virus, how the virus transmits and replicates, various antiviral agents for textiles and their working mechanism, and the application procedure of various synthesized and bio-based antiviral compounds on textiles have been discussed in this paper. Finally, the present paper compares the existing antiviral finishing on textiles in terms of its effectiveness, durability and skin-friendliness and, following that, discusses the possibilities of using antiviral textiles in various sectors.

Nanomaterials for UV protective textiles

Harmful portion of ultraviolet (UV) radiation is one of the significant physical carcinogen in our natural environment. The damage caused by UV exposure to our body is cumulative and builds up over the years. UV protective textiles have been used to protect the wearer from harmful UV radiation. UV blocking effect of textile depends on various parameters viz. fiber type, yarn structure, weave, fabric construction factor, finishes, dyes etc. Further, UV protective property of textiles can be improved by incorporating UV blocking agent in the textile matrix. Several nanomaterial possesses excellent UV blocking effect and these could be incorporated into the textile matrix to improve the UV blocking properties of textiles. In this review, author discuss the various conventional ways to impart UV blocking property to the textile materials. Author also survey the current state-of-the-art of nanomaterials based UV protective textiles, mechanism of UV blocking properties of various nanomaterials, provide an overview of UV protective fabric manufacturing techniques and also discuss the durability of nanomaterials treated UV protective textiles. Finally, the manuscript has been concluded with few major challenges for the development of UV protective textiles by using nanomaterials.

Advances in Functional and Protective Textiles

Shahid ul-Islam, Bhupendra Singh Butola (eds.) 1st edition, June 2020, 678 pages, € 263, US$ 280, £ 216 Woodhead Publishing Ltd., Cambridge/UK Hardcover ISBN: 978-0-12820-257-9; eBook ISBN: 978-0-12822-676-6