Senem Kursun Bahadir

Thermal analysis of e-textile structures using full-factorial experimental design method

e-Textiles are structures that have properties such as sensing, actuating, communicating, and generating/storing power. Since e-textile structures may be in contact with skin, it is essential to have low temperatures when they are functioning. In this article, temperatures obtained on the e-textile structures were analyzed by taking into account weave type, linear resistance of conductive yarns, base yarn type, and voltage values using full-factorial experimental design method. e-Textile structures were designed using different conductive yarns with different linear resistance values in different weave-type configurations. Thermal analysis was carried out under different voltage values to observe temperature variations over the conductive yarns positioned in the fabric structure. It was found that linear resistance of conductive yarns and its interaction with voltage values considerably affect the temperature of the e-textile structures, and the temperature observed over the conductive yarns is directly proportional to the linear resistance of conductive yarns. Additionally, it was observed that plain fabric samples reach lower temperatures than twill and sateen fabric samples.

The Use of Hot Air Welding Technologies for Manufacturing E-textile Trasmission Lines

This study investigated the potential possibilities for obtaining textile transmission lines by incorporating conductive yarns into fabrics through a hot air welding process. Hot air sealing for obtaining textile transmission line was conducted using 100 % PES woven fabric, GoreTex® waterproof welding tape and seven different conductive yarn types, in order to form different textile transmission lines. By manufacturing using a hot air seam-sealing machine different welding parameters like welding temperature, pressure and velocity were chosen in order to find an optimal welding process for the selected fabric samples. The effects of welding parameters were examined on the electrical properties of the textile transmission lines in terms of conductivity and signal-transferring capability. Besides, the bending properties and morphologies of the welded textile transmission lines were also characterized and subjective evaluations of the appearances of textile transmission lines like puckering and the visual appearances of the surface sides of the welded textile transmission lines. The results based on conductivity and signal transferring capabilities were really promising for the manufacturing of etextile transmission lines via hot air welding technology. Moreover, the results based on bending properties showed that the lower the welding parameters the less rigid the hot air welded textile transmission lines became after welding all the used conductive yarns. Further, suitable combinations of welding parameters with the used components of textile transmission assured suitable visual appearances of the welded textile transmission lines. In this respect this research work offers a usage for hot air welding technology regarding the formations of textile transmission lines which are reliable and durable in functionality while still preserving the textiles’ aspects.

An Analysis on the Moisture and Thermal Protective Performance of Firefighter Clothing Based on Different Layer Combinations and Effect of Washing on Heat Protection and Vapour Transfer Performance

Fabric assemblies for firefighting clothing have been tested for heat protection and comfort. The constituent materials and fabric structures have been specifically selected and tailored for firefighters’ clothing. In order to do this, four types of outer shell fabrics, four types of moisture barrier fabrics, and four types of heat barriers with different weights and material compositions were used to make a multilayered fabric assembly. Heat transfer (flame), heat transfer (radiant), and water vapour resistance tests were conducted according to the latest EN469 test standard which also recommends washing tests. These tests reveal that material content and material brand have considerable effect on the required performance levels of heat protection. In addition, while washing tests have improved water vapor transfer properties, they have a deteriorating effect on heat protection performance. Considering heat protection and moisture comfort properties, the optimal assemblies are thereby identified.

A study on the beam pattern of ultrasonic sensor integrated to textile structure

Purpose – During the past decades, several researchers have introduced devices that use sonar systems to detect and/or to determine the object location or to measure the distance to an object using reflected sound waves. The purpose of this paper is to use sonar sensor with textile structure and to test it for detection of objects.Design/methodology/approach – In this study, a sonar system based on intelligent textiles approach for detection of objects has been developed. In order to do this, ultrasonic sensor has been integrated to textile structures by using conductive yarns. Furthermore, an electronic circuit has been designed; PIC 16F877 microcontroller unit has been used to convert the measured signal to meaningful data and to assess the data. The algorithm enabling the objects detection has also been developed. Finally, smart textile structure integrated with ultrasonic sensor has been tested for detection of objects.Findings – Beam shape is presented related to identified object and compared with t...

Color and electrical resistance evaluation of cotton fabrics composed of stainless steel yarns treated with direct and reactive dyes

The aim of this work was to investigate the color change of cotton fabrics with stainless steel yarns incorporated. In order to establish the impact of conductive yarns’ composition properties in the fabric, concentrations and two different dyeing profiles based on direct and reactive dyes chemistry were applied. The success of this novel e-textile design was evaluated colorimetrically with two different dye concentrations as well through various linear electrical resistances to obtain solid statistical conclusions. The dyed samples were colorimetrically evaluated and the electrical resistances of conductive yarns inside the fabric structure were compared and discussed statistically before and after dyeing. The results provided evidence that dyeing has great influence on electrical resistances of conductive yarns used as transmission lines for electro-textile applications. The greatest changes in electrical resistances were observed with samples including thin conductive yarns and untwisted conductive yarn after dyeing processes. Additionally, it can be concluded that the presence of stainless steel conductive threads significantly retards the dyeing processes depending on the dyestuff concentration and weave type, resulting in major color differences, especially when plain weave type is used or the dyestuff concentration is less than 1% for twill and sateen weaves.

Developing a Smart Clothing System for Blinds Based on Information Axiom

Abstract In this paper, a novel approach is proposed to determine the electronic system components of a smart clothing system design developed for blinds. The integration of diverse components which are developed and produced by different technologies and materials is a major challenge in a smart clothing system technology. Therefore, an integrated methodology based on fuzzy analytic hierarchy process (AHP) and fuzzy information axiom is used for the solution of this problem.

Optimization of hot air welding process parameters for manufacturing textile transmission lines for e-textiles applications: Part I: Electro-conductive properties

This paper presents optimization of the hot air welding process parameters for the formation of textile transmission lines and the electro-conductive properties of these manufactured transmission lines. A dedicated manufacturing set-up has been developed to allow a reliable and flexible textile signal transmission line at adequate conductivity. In order to manufacture textile transmission lines, different welding parameters with different conductive yarns and welding tapes were considered. Layered fabric structures consisting of textile transmission lines and fabrication tolerances were determined, as well as electro-conductive properties for welded samples. It was found that the choice of welding parameters, depending on the materials used for the formation of textile transmission lines, is extremely important for obtaining good electro-conductive properties. In addition, welding tapes and thermoplastic materials play an important role during the set-up of welding process parameters. Results statistically confirmed that welding tapes with conductive yarns can significantly cause a variety of changes in the signal qualities of welded textile transmission lines. The obtained results based on conductivity and signal-to-noise ratios are really promising for the manufacturing of e-textile transmission lines via hot air welding technology.

Fabric hand of a dry finished wool fabric

The appearance and hand of end-use fabrics has become more and more important when purchasing textile fabrics. The finishing parameters have complex influences on the large number of changes that occur in fabric properties during finishing processes. This study focused on the influences of different finishing parameters on mechanical and surface properties in order to discover the most appropriate finishing process according to the requirements of fabric handle and appearance. The KES-F system was used to evaluate fabric hand objectively, as well as the mechanical and surface properties of a woven wool fabric. Four finishing processes were selected, which differed in relation to the temperature when drying (T1=160 °C, T2=180 °C) and processing conditions during autoclave decatizing (T1=95 °C, p1=0.4 bar, T2=110 °C, p2=1 bar). The effect of the influential parameters inside four different finishing processes on the mechanical properties and hand of a selected woven fabric was evaluated using the analysis of variance. The results show that tensile properties are much more influenced by the belt pressing process while bending and shear properties are influenced by continuous decatizing process, which is the process that mostly improves fabric stability at the beginning of the dry finishing cycle. When the primary and total hand values were observed, it could be seen that applying chemicals during belt pressing had some consequences, the impacts of which could be observed directly in the resulting hand values.

Modeling of surface temperature distributions on powered e-textile structures using an artificial neural network

An artificial neural network (ANN) model is constructed to derive the surface temperature of e-textile structures developed for cold weather clothing. A series of textile transmission lines made of different types of conductive yarns, insulated by using different types of seam tapes, were enclosed in a thermoplastic textile structure via hot air welding technology, and then they were powered with different levels of specific voltages in order to obtain different heating levels. The surface temperatures of the powered e-textile structures were measured using a thermal camera. The experimental input variables, sample type, temperature, feeding speed, resistance of samples, applied voltage and current were used to construct an ANN model and the outputs of surface temperature and electric power dissipated were used to test the prediction performance of the developed model. It was concluded that the ANN provided substantial predictive performance. Simulations based on the developed ANN model can estimate the surface temperature distributions of powered e-textile structures under different conditions. The ANN model developed for prediction of electric power dissipated was very successful and can be useful for e-textile product designers as well as textile manufacturers, particularly for cold weather protection products such as jackets, gloves and outdoor sleeping mats.

Performance Evaluation of Welded Knitted E-Fabrics for Electrical Resistance Heating

This paper presents a study conducted on electrical resistance heating of knitted e-fabric structures including silver plated conductive yarns. The study further investigates the application of ultrasonic welding technology on these knitted e-fabrics in order to see their effect on heating performance. Thermal analysis was carried out under different voltage values to observe temperature variations over the knitted e-fabrics. It was found that the linear resistance of conductive yarns and its interaction with voltage values considerably affect the temperature as well as heating performance of the e-fabrics. In addition, ultrasonic welding parameters also need to be carefully controlled in order to obtain sufficient heating performance.