Metal Content and Structure of Textiles in Textile Metal Threads in Croatia from 17th to 20th Century

Textile metal threads were used to decorate historical Croatian textiles. There are three basic types of metal threads usually used on historical textiles in Croatia. These are narrow stripes, wires, and combined metal textile yarn called “srma”, made of metal thread spirally wrapped around the nonmetal textile yarn. Textile yarns were made of silk, linen, wool, or cotton. Metal threads were primarily made of gold, silver, and copper, and different alloys of these metals or threads are layered in the structure. Analysis of metal threads with three different methods was made and the most adequate method for the analysis of metal threads from historical textiles was established. Metal thread analysis was performed with scanning electron microscopy with an energy-dispersive X-ray detector (SEM-EDX), which was determined to be the most suitable for the analysis of historical textiles if cross-section analysis of metal threads is also performed. Textile threads from combined metal textile threads were analysed with a light microscope. This information of the metal threads’ content and structure as well as the composition of textile thread can lead to an understanding of the technology of production threads and also temporal and spatial dating of textile objects which is helpful to conservators and restorers of valuable historical textiles.

Stretchable Textile Yarn Based on UHF RFID Helical Tag

In the context of wearable technology, several techniques have been used for the fabrication of radio frequency identification (RFID) tags such as 3D printing, inkjet printing, and even embroidery. In contrast to these methods where the tag is attached to the object by using sewing or simple sticking, the E-Thread® technology is a novel assembling method allowing for the integration of the RFID tag into a textile yarn and thus makes it embeddable into the object at the fabrication stage. The current E-Thread® yarn uses a RFID tag in which the antenna is a straight half-wave dipole that makes the solution vulnerable to mechanical strains (i.e., elongation). In this paper, we propose an alternative to the current RFID yarn solution with the use of an antenna having a helical geometry that answers to the mechanical issues and keeps quite similar electrical and radiative properties with respect to the present solution. The RFID helical tag was designed and simulated taking into consideration the constraints of the manufacturing process. The helical RFID tag was then fabricated using the E-Thread® technology and experimental characterization showed that the obtained structure exhibited good performance with 10.6 m of read range in the ultra high frequency (UHF) RFID band and 10% of tolerance in terms of elongation.

Surface Modification of Commercial Cotton Yarn as Electrode for Construction of Flexible Fiber-Shaped Supercapacitor

In this study, we report on the rational design and facile preparation of a cotton-reduced graphene oxide-silver nanoparticle (cotton-RGO-AgNP) hybrid fiber as an electrode for the building of a flexible fiber-shaped supercapacitor (FSSC). It was adequately characterized and found to possess a well-defined core−shell structure with cotton yarn as a core and a porous RGO-AgNP coating as a shell. Thanks to the unique morphological features and low electrical resistance (only 2.3 Ω·cm−1), it displayed attractive supercapacitive properties. When evaluated in a three-electrode setup, this FSSC electrode delivered the highest linear and volumetric specific capacitance of up to ca. 12.09 mF·cm−1 and ca. 9.67 F·cm−3 with a satisfactory rate capability as well as a decent cycling stability. On the other hand, an individual parallel symmetric FSSC cell constructed by this composite fiber fulfilled the largest linear and volumetric specific capacitance of ca. 1.67 mF·cm−1 and ca. 0.67 F·cm−3 and offered the maximum energy density, as high as ca. 93.1 μWh·cm−3, which outperformed a great number of graphene- and textile yarn-based FSSCs. Impressively, bending deformation brought about quite a limited effect on its electrochemical behaviors and almost no capacitance degradation took place during the consecutive charge/discharge test for over 10,000 cycles. Consequently, these remarkable performances suggest that the currently developed cotton-RGO-AgNP fiber has considerable application potential in flexible, portable and wearable electronics.

The sustainability quotient: a trader’s trade-offs

Learning outcomes The learning outcomes of this case will help the participants to assess values, motivations and interpersonal relations that exist and evolve in a family firm; analyze individual-level strategies in absence of business growth strategy and succession plan; expose trade-offs associated with natural inheritance or merit-based succession; reveal alternate strategies of coping with conflicts in multi-generation multi-family firms. Case overview/synopsis This case focuses on leadership, succession and conflicts at Dalal Group, a 50 years old textile yarn trading family-run business. The trading business has 10 members across three generations working in it. The business is making profits but the growth of the business is not synchronous to the number of family members working in it. As revenues are stable and buyers’ network is not growing, an internal tussle has begun among the members to preserve business resources available to them. The founder, who is also the Managing Director of the Group, is about to retire in a couple of years but there is no clear successor to his position. In the absence of a business growth plan and uncertainty about the next leader, members are clueless about their own future and that is affecting their interpersonal relations at work. This has triggered the need for decision and action by the founder, failing which the business might disintegrate. The case author has used personal interview methods and secondary sources like annual reports and manuals of the company to collect data and information. Complexity academic level Senior Undergraduates, MBA (Entrepreneurship and Family Business), MBA. Supplementary materials Teaching notes are available for educators only. Subject code CSS 6: Human resource management.

Vibration-Sensing Electronic Yarns for the Monitoring of Hand Transmitted Vibrations

Overexposure to hand transmitted vibrations (HTVs) from prolonged use of vibrating power tools can result in severe injuries. By monitoring the exposure of a worker to HTVs, overexposure, and injury, can be mitigated. An ideal HTV-monitoring system would measure vibration were it enters the body, which for many power tools will be the palm and fingers, however this is difficult to achieve using conventional transducers as they will affect the comfort of the user and subsequently alter the way that the tool is held. By embedding a transducer within the core of a textile yarn, that can be used to produce a glove, vibration can be monitored close to where it enters the body without compromising the comfort of the user. This work presents a vibration-sensing electronic yarn that was created by embedding a commercially available accelerometer within the structure of a yarn. These yarns were subsequently used to produce a vibration-sensing glove. The purpose of this study is to characterize the response of the embedded accelerometer over a range of relevant frequencies and vibration amplitudes at each stage of the electronic yarn’s manufacture to understand how the yarn structure influences the sensors response. The vibration-sensing electronic yarn was subsequently incorporated into a fabric sample and characterized. Finally, four vibration-sensing electronic yarns were used to produce a vibration-sensing glove that is capable of monitoring vibration at the palm and index finger.

Prediction of Deformation Processes of Polymeric Materials Taking into Account Plastic Irreversible Deformation

The need to develop new methods for predicting the properties of polymeric materials is also justified by the goal of designing new innovative materials with the required functional properties and increased competitiveness. The classical methods for predicting deformation processes of polymeric materials are based on the numerical solution of integral constitutive equations for polymer viscoelasticity of the Boltzmann-Volterra type, which do not consider corrections for the irreversibility of the plastic component of deformation and therefore can lead to significant prediction errors. To improve the accuracy of predicting the deformation processes of polymer materials it is proposed to introduce a physically justified correction with account for the irreversibility of the plastic component of deformation. The introduction of this correction significantly increases the reliability and accuracy of predicting the functional and operational properties of polymer materials. The article suggests demonstrating the methods for predicting deformation processes with the example of the polyester textile yarn made of polyester fibers. Unlike many other synthetic fibers, the polyester ones have such important properties as structural stability, softness along with high strength, elasticity, resilience, tensile strength, crease and pilling resistance, temperature regulation, shape retention, etc. The polyester fiber has a hollow structure and its single components have the form of spiral springs which give the effect of a springy base when intertwined.

Study on the mechanics of textile thread in woven

Specialists in the weaving industry are often interested in the question of what tension of the warp and weft threads must be set on the weaving machine to produce a particular fabric. Along with this, they are interested in the question of what is the relationship between these parameters and the structure of the fabric, how much it is necessary to increase or decrease the tension of the warp and weft threads when changing the assortment of fabric. These problems arise because the correct thread tension on weaving machines increases the productivity of equipment and labor, and also improves the quality of the fabrics produced. The current state of the mechanics of a weighty deformable flexible thread on a plane and other forms of guides do not take into account the rigidity of the threads on the friction surface, since this parameter is determined by the type and type of threads, the linear density of the threads and the elastic properties of the threads. Therefore, the article analyzes the work on the mechanics of textile yarn and studies of the tension of the yarns were carried out depending on the radius of friction, angle of friction, coefficient of friction and stiffness of the yarns.