Search

In this study, the thermal insulation of cold protective outerwear under various clothing combinations and ambient conditions was estimated using a thermal manikin. A series of cold protective outerwear, worn with various types of underwear, were evaluated in a conditioned room to explore the dependence of outerwear thermal insulation on the underwear. Besides, statistical studies were utilized to study the effect of ambient temperature on the thermal insulation performance of cold protective clothing ensembles. The thermal insulation of outerwear was observed to be different when it was measured with various fit styles, thicknesses and combinations of underwear. These discrepancies can be attributed to the variation in the air gap between clothing layers and the presence of stagnant air within the porous clothing. Furthermore, the ambient temperature was found to be a dominant factor affecting the thermal insulation performance of the clothing ensembles with high air content, as the airflow inside the porous material may be aggravated by the larger temperature difference between the clothing and the environment. Based on this study, ambient conditions for the assessments of different kinds of clothing can be divided into five groups, simulating the actual-used scenarios. The findings of this study are anticipated to enhance the comprehensiveness of thermal insulation evaluations for clothing systems and assist in the identification of optimal clothing choices for diverse ambient conditions. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA), a new renewable and environmentally friendly polymer material, has gained significant attention in recent years. However, its application is limited by challenges such as poor thermal stability, brittleness and limited impact resistance. At present, PLA is predominantly modified through blending, filling and copolymerization methods. Although the above modification methods can effectively improve the properties of PLA, there are still some deficiencies in some places. In this work, CNF/Ti3C2Tx/PLA composites were prepared by impregnation with poly(lactic acid) (PLA) and cellulose nanofibers (CNF), a new two-dimensional material Ti3C2Tx, and a complete CNF membrane as a support framework. The effects of CNF and Ti3C2Tx incorporation on the thermal, mechanical and electromagnetic shielding properties of PLA were investigated using various characterization techniques including FT-IR, XRD, DSC, TGA, tensile testing and electromagnetic test characterization. The results showed that CNF can improve the thermal stability and crystallinity of PLA, where the crystallinity can reach 23.5%. CNF synergized with Ti3C2Tx to improve the mechanical properties of PLA, and the tensile strength was increased by 64.29%. Furthermore, Ti3C2Tx imparted electromagnetic shielding properties to PLA composites. The findings expand the application of PLA composites in the field of electromagnetic shielding. [ABSTRACT FROM AUTHOR]

To explore the skin moisturizing performance of aloe viscose fiber seamless knitted fabric, this experiment takes the different yarn-blending ratios of aloe viscose fiber and viscose fiber, as well as three different tissue structures as factors, establishes a sample scheme according to full factor experimental tests on skin hydration and trans epidermal water loss (TEWL) after the sample fabric had been wrapped around the skin, and uses two-way and one-way ANOVA in SPSS and the Duncan multiple comparison method. The test data were analyzed to study the influence of different materials and the structure of the veil on the moisture retention of the fabric. The results show that the sample scheme with the largest change rate of skin hydration is when the raw material of the veil is aloe viscose/viscose 100/0 yarn, and the structure is 1 + 3 simulated rib. The sample scheme with the minimum change rate of TEWL is when aloe viscose/viscose 75/25 yarn is used as the raw material of the veil, and the structure is 1 + 1 simulated rib, which provides a theoretical basis for the research and development of moisturizing knitted fabric. [ABSTRACT FROM AUTHOR]

An air layer enclosed at the interface was largely responsible for the insulation results of multilayer fabrics obtained from experiments. In this study, a three-dimensional finite element method model, in which the air layer enclosed at the interface of multilayer fabrics was ignored, was developed to calculate the fabric thermal resistance, and the result obtained from the fabric model was independent of the air. A Thermolab II Tester KES-F7 was also used to measure the thermal resistance of fabrics, and the experimental results were influenced by the air layer. By comparing the simulation and experimental result, the air layer thermal resistance was determined, and then an estimating equation, which can be used to estimate the fabric and air layer thermal resistance for multilayer fabrics, was proposed. The results suggested that the surface roughness of fabrics was strongly related to the air layer thermal resistance, with a linear relationship between them. Moreover, for multiple layers stacked by different fabrics, the air layer thermal resistance at the interface was mainly decided by the fabric with the rougher surface. An estimating equation was also developed to predict the thermal resistance of multilayer fabrics and good correlation between predicted and experimental values was observed. [ABSTRACT FROM AUTHOR]