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Analysis of the heat transfer property with the sandwich fabrics based on ANSYS workbench and Alambeta
(Wydawnictwo Politechniki Łódzkiej, 2022) Wang, Dan; Hu, Shi; Kyosev, Yordan; Kremenakova, Dana; Militky, Jiri
As more and more attention is paid to the thermal comfort of clothing, academic research on the heat transfer properties of textile materials is becoming more and more important. In recent years, the application of simulation software to analyze the heat transfer properties of fabrics has become a research hotspot. In this paper, the ANSYS workbench simulation software is used to simulate the heat transfer property of a kind of sandwich fabric. The results obtained by establishing different models show that the application of single-layer fabric with different thermal resistances in the sandwich fabric will lead to greatly different thermal resistances of sandwich fabric; the same material has different thicknesses, and its thermal resistance will increase with the thickness; the same single-layer fabric with different combination positions will cause the thermal resistance of the sandwich fabric to change. At the same time, the software simulation values are compared with the actual measured values. It can be found that the two sets of data have the same trend, but the data of the former is significantly higher than the latter. The reason is that the model's porosity is much smaller than the actual sample.
Comparative evaluation effects of thermal degradation, burning behavior, and intumescent char formation of cotton fabrics coated with alkaline and acidic casein solutions
(Wydawnictwo Politechniki Łódzkiej, 2022) Faheem, Sajid; Nahid, Nazia; Wiener, Jakub; Mazari, Adnan; Baheti, Vijay; Militky, Jiri
The present research work was aimed to investigate and study the effect of coatings of different concentrations and pH of aqueous casein solutions on thermo-oxidative properties, flame retardant performance, and intumescent char formation phenomenon of cotton fabrics. The flame retardant behavior of fabric samples was found to increase with an increase in the concentration of casein solutions in both alkaline and acidic pH conditions. The casein solution of acidic pH was found to yield more char residue than the alkaline casein solution, which evinced their better thermo-oxidative properties. The SEM micrographs of char residues also revealed the formation of stronger and coherent char with the presence of intumescence. Furthermore, the phenomenon of intumescence was largely observed in the case of cotton fabric samples coated with acidic casein solution.
In-situ green synthesis of zinc oxide nanoparticles (ZnO NPs) onto the cotton fabrics by neem (azardirachta indica) leaf extract
(Wydawnictwo Politechniki Łódzkiej, 2022) Javed, Asif; Wiener, Jakub; Saskova, Jana; Militky, Jiri
This research work was carried out for the green in-situ synthesis of ZnO nanoparticles onto the 100% cotton fabric. Zinc nitrate hexahydrate [Zn(NO3)2.6H2O] was used as precursor and the Neem (Azardirachta Indica) leaf extract was used as reducing agent. Scanning electron microscopy (SEM) and X ray diffraction (XRD) were done to investigate the surface morphology and characteristics of developed samples. Moreover the ultraviolet protection factor (UPF), UVA blocking %age, UVB blocking %age, and antibacterial properties were examined. The SEM and XRD confirmed the deposition of ZnO NPs onto the fabric having crystalline structure. The evaluated samples showed very excellent results for, UPF rating, UVA blocking %age, UVB blocking %age, and antibacterial properties.
Resistive heating performance of waste cotton-derived carbon obtained by salt-assisted hydrothermal carbonization
(Wydawnictwo Politechniki Łódzkiej, 2022) Wang, Yuanfeng; Venkataraman, Mohanapriya; Militky, Jiri
In this work, cotton waste-derived hydrochar was prepared via copper salt-assisted hydrothermal carbonization. The morphology the as-obtained copper-doped hydrochar was examined by SEM. The resistive heating properties of the hydrochar was studied by applied various voltages. In addition, characteristics parameters were calculated by fitting data from the heating and cooling section. The relevance between temperature and the corresponding required electrical power was also established. The results showed that copper-doped hydrochar exhibited excellent resistive heating range and electrical energy efficiency.
Thermal behavior of a multi-layer laminated fabric containing PCMS
(Wydawnictwo Politechniki Łódzkiej, 2022) Yang, Kai; Zhang, Xiuling; Wiener, Jakub; Venkataraman, Mohanapriya; Zhu, Guocheng; Yao, Juming; Militky, Jiri
Phase change material (PCM)-incorporated fabrics have been developed for personal temperature regulation. To avoid leakage of melting PCMs from the fabric, various methods have been developed, including microencapsulated PCM (MPCMs), form-stable PCMs (FSPCMs) and solid-solid PCMs (SSPCMs). However, the poor physical property and the limited thermal behavior of such materials are found. To keep the thermal behavior of PCM-incorporated fabrics without leakage as high as possible, a multi-layer PCM fabric consisting of PEG-coated viscose fabric and PA 6-laminated fabric was proposed in this work. The leakage and thermal buffering effect of the multi-layer laminated fabric containing PEG were investigated. As a result, the PA 6-laminated fabric successfully resisted against the melting of PEG and no leakage was found. Correspondingly, the thermal buffering effect was found. We propose that this work provides a facile method to fabricate PCM fabrics and extends the application of laminated fabrics.