Evaluating mechanical and thermal characteristics of garment systems or their segments is important in an attempt to provide optimal or at least satisfying levels of comfort and safety, especially in the cold environment. The target groups of users may be athletes engaged in typical sports that are trained in the cold, as well as football players that play matches and train outdoors during the winter season. Previous studies indicated an option to substitute the inner layers of an intelligent garment with polyurethane inflated chambers (PIC) to increase and regulate thermal insulation. In this paper, the authors investigate the mechanical properties of polyurethane material with and without ultrasonic joints. Furthermore, they investigate the potential of designed PICs in terms of efficiency and interdependence of air pressure and heat resistance. The results indicated that an inflated PIC with four diagonal ultrasonic joints has the highest ability to maintain the optimal thermal properties of an intelligent clothing system. The influence of direction and number of ultrasonic joints on the mechanical properties of polyurethane material is confirmed, especially in terms of compression resilience and tensile energy.

This paper presents the measurement results of the thermal insulation of the outer shell, thermal inserts, and clothing systems, as well as a comparative analysis of the thermal insulation of multi-layer thermal inserts in a thermal jacket intended for professional services in cold weather. Detachable thermal inserts are made of double-faced, diamond-shaped quilted lining with different masses per unit area, and together with the jacket, they form clothing systems with different thermal properties. Tests of the thermal properties of clothing were performed on a thermal manikin. They showed that an increase in the mass of thermal insulation textile materials contributes to an increase in the thermal insulation properties of clothing and are insufficient for a complete analysis of the thermal properties of clothing. Therefore, for the first time, three new parameters of integration efficiency of the thermal insert, thermal insulation efficiency parameters, and efficiency parameters of the integration of the textile material integrated into the clothing system were introduced. Based on these parameters, it is possible to perform an effective and accurate comparative analysis of the thermal insulation of multi-layer thermal inserts in clothing. This makes it possible to apply exact scientific methods largely in the technical design of the thermal properties of integrated textile materials, instead of experience-based methods as in the past.

This paper deals with the idea that one of the inner thermal insulation layers of a garment may be replaced by expanding the air chambers in the form of an expanding thermal insert, which is inflated with air causing the chamber thickness and thermal insulation properties to change. The chambers are controllable so that the thermal insulation properties can be changed, and by connecting with an appropriate control, the architecture of an article of clothing can be designed such that it can independently monitor changes in its environment and change its thermal insulation properties in accordance with changes in its external and internal environment. In this way, it acquires the characteristics of intelligent clothing. The paper presents idea concepts, development, structural architecture and general characteristics of two generations of intelligent clothing with adaptive thermal insulation properties. The expanding thermal inserts are situated between the outer shell and the lining and are the key element of this type of new clothing. In the first generation of intelligent clothing the expanding inserts were designed in combination with three horizontal chambers that can be sealed in three horizontal layers, whereby it is possible to make six adaptable discontinuous levels of thermal insulation. In the second generation, ribbed expandable chambers were used. Their thickness is continuously changeable according to the pressure change in the chambers, whereby the value of thermal insulation of the chambers can be continuously adapted. The functioning of this clothing is based on the integration of sensors for internal and external temperature and air pressure in the chambers, on a microcontroller with regulation software and actuators to control the expanding insert. When wearing this kind of clothing, the microcontroller system monitors changes in ambient temperature and clothing microclimate depending on the wearer’s physical activity, compares them with the achieved thermal protection and makes autonomous decisions on the required increase or decrease in thermal protection. Since this clothing follows changes in its internal and external environment, estimates the real and necessary state, makes decisions and independently performs the adaptation of thermal insulation to a level that it ensures constant thermal comfort, it can be claimed that such a garment has the basic attributes of intelligent clothing. The paper describes the functioning of two types of thermal insulation chambers, the sensor system used, micropneumatic components, the microcomputer system, the flow chart of the algorithm of intelligent behavior, the complete built-in architecture of all technical subsystems, features of the first and second generation and the observed good and bad points of the conceptual approach to the development of intelligent clothing with adaptive thermal insulation properties.

The compression properties of welded seams depending on welding parameters using the hot wedge and hot air welding technique, ultrasonic welding technique, and high-frequency welding technique were studied. The compression properties, expressed by parameters such as compressional energy WC, compressional resilience RC, linearity LC, and compressibility C, are important information about the welded seam quality in terms of touch, voluminosity, stiffness, and flexibility of the welded seam. KES-FB and FAST measurement systems were used to test the compression properties of the welded seams. Based on the analysis of the results obtained, the influence of the welding parameters on the compression properties of the welded seam was determined. The results of the investigation showed that improperly selected welding parameters, such as the supply or introduction of too much heat into the material to be welded or too long exposure of the material in the weld zone to heat, result in welded seams with expressive extrusion edges, which affects the quality of the welded seams. These welded seams have very low values of compressional resilience RC and very high values of compressional energy WC and compressibility C.

This paper presents a detailed exploration of the development and characterization of multifunctional dual-purpose woven fabrics for thermal protective clothing. Through this research, 69 woven fabric prototypes have been carefully designed and produced, integrating various raw materials, yarn, and woven fabric construction parameters, with the aim of optimizing thermal protection properties while ensuring comfort and durability. The analysis led to the identification of two optimal woven fabric samples, which, upon further testing, exhibited exceptional dimensional stability, crease recovery, tear resistance, as well as abrasion and water resistance. Furthermore, the thermal properties were evaluated, demonstrating exceptional flame resistance, limited heat transmission, and high thermal insulation. Additionally, the study evaluated dynamic thermal properties, contact conductive heat transfer, air permeability, water vapour resistance, and thermal resistance of two clothing systems constructed from selected woven fabrics. Statistical analysis confirms significant differences between clothing systems, highlighting the influence of yarn composition and fabric structure on thermal performance and comfort, where one system exhibits better thermal insulation characteristics suitable for colder environments while the other excels in breathability for warmer climates. The developed woven fabrics meet high standards for protective clothing against heat and flame, surpassing currently available comparable woven fabrics on the market in terms of efficacy and performance. This research provides insights into the intricate balance between protection, comfort, and durability of woven fabrics, contributing to advancements in protective textile technology.

The welding of foils, textiles, and textile composites made of thermoplastic polymer materials using machines with an ultrasonic rotary sonotrode is a high-tech welding technique. Many authors have dealt with only a few parameters in earlier papers, mainly mentioning the speed, i.e., the welding time, and the power of the ultrasonic generator. In this paper, the acoustic model of ultrasonic welding is defined. Based on the model, a group of 44 different parameters important for ultrasonic welding of polymer materials has been summarised, namely 12 parameters of the polymer material, 11 general acoustic and electroacoustic parameters, and 21 technical parameters depending on the ultrasonic machine. Based on this, a comprehensive mathematical derivation was carried out, linking parameter groups with other findings from acoustics, thermodynamics of polymers, and technical and technological parameters of welding polymer materials. The most important parameters are the power of the ultrasonic generator and the welding time, which in practice are adjusted to produce a solid weld. The method of measuring the amplitude of the sonotrode using a photonic sensor is presented in this paper. For 42 groups of welds done at various welding speeds and ultrasonic generator powers, the breaking forces of ultrasonic welds were measured. There are illustrations of power dependence and breaking forces. The accuracy of the mathematical model was confirmed by comparison with the calculation results based on the findings of these measurements.