The main aim of this experimental work is to find out possible improvement in thermal protective performance of firefighter protective clothing when subjected to different level of radiant heat flux density. Firefighter protective clothing normally consists of three layers: outer shell, moisture barrier and thermal liner. When thermal protective performance of firefighter protective clothing is enhanced, the time of exposure against radiant heat flux is increased, which will provide extra amount of time to firefighter to carry on their work without suffering from severe skin burn injuries. In this study, the exterior side of outer shell was coated with nano-silver metallic particle through magnetron sputtering technology. Coating of outer shell with nano-silver particles was performed at three level of thickness, i.e. 1, 2 and 3 µm, respectively. All the uncoated and silver coated specimens were then characterized on air permeability tester, Permetest and radiant heat transmission machine. It was observed that coating has insignificant difference on the air and water vapor permeability of specimen and a significant decline was recorded for the value of transmitted heat flux density Qc (kW/m2) and percentage transmission factor (%TF Qo) as compared to uncoated specimen when subjected to 10 kW/m2 and 20 kW/m2 indicating improvement of thermal protective performance. These values go on further reduction with increase in thickness of coating layer of nano-silver particles.
In the field of textile comfort of smart textiles, the breathability of the material is very important. That includes the flow of air, water and water vapours through the textile material. All these experiments are time consuming and costly; only air permeability is much faster and economical. The research is performed to find correlation between these phenomena of breathability and to predict the permeability based on only the air permeability measurement. Furthermore, it introduces a new way of expressing the Ret (water vapour resistance) unit according to SI standards as it is connected with the air permeability of garments. The need to find a correlation between air permeability and water vapour permeability is emphasised in order to facilitate the assessment of clothing comfort. The results show that there is a strong relation between air permeability and water vapour permeability for most of the textile material.
This study investigated the development of Pullulan/Collagen nanofiber scaffolds integrated with mesenchymal stem cells (MSCs) to enhance chronic wound healing. The combination of these biopolymers aims to optimize the scaffold properties for cell growth, viability, and tissue regeneration. Materials and Methods: Pullulan, Collagen, and Pullulan/Collagen composite nanofibers were fabricated using electrospinning. The fibers were characterized using scanning electron microscopy (SEM) to determine the fiber diameter, and Fourier-transform infrared spectroscopy (FTIR) was employed to assess the molecular interactions. Cell viability was evaluated using MSCs cultured on the scaffolds and apoptosis assays were conducted to assess cell health. Distilled water was used as the solvent to maximize biocompatibility. Results: SEM analysis revealed that Pullulan nanofibers exhibited a larger average diameter (274 ± 20 nm) compared to Collagen fibers (167.03 ± 40.04 nm), while the Pullulan/Collagen composite fibers averaged 280 ± 102 nm. FTIR confirmed the molecular interactions between Pullulan and Collagen. Regarding biocompatibility, the Pullulan/Collagen scaffold demonstrated superior cell viability at 99% compared to 91% for Pullulan alone. Apoptosis assays indicated significantly lower necrosis rates for the composite scaffold (1.29%) than for the Pullulan-only scaffolds (2.35%). Conclusion: The use of distilled water as a solvent played a critical role in increasing cell viability and facilitating healthy proliferation of MSCs without cellular damage. Additionally, the reduced platelet activation and macrophage activity (0.75-fold for both) further supported the biocompatibility of the Pullulan/Collagen scaffold, demonstrating its potential for tissue engineering and chronic wound healing applications.
Thermal absorptivity is an indicator of warm and cool feeling of textile materials. An equation based on thermal absorptivity of polyester in solid form, porosity of a fabric, and relative contact area of human skin and fabric surface has been developed to characterize thermal absorptivity of fabric. For verification of suggested model, 15 knitted rib fabrics were produced using 100% polyester yarn and having different surface profile. ALAMBETA semiautomatic non-destructive instrument has been used for measuring the effective thermal absorptivity of knitted rib fabric. It was found that the suggested simple theoretical model exhibits significant agreement with the measured thermal absorptivity values of knitted rib fabric, which endorsed the approach applied.
In industrial sewing, needle heating is a key problem that limits the further increase of sewing speed, and hence the productivity. Heat is generated during the sewing process because of friction between the needle and the sewing thread as well as between the needle and the fabric. The high temperature of the needle affects the quality and productivity of the sewing. The problem of needle temperature rise due to friction heat generation is considered in this paper and a simple analytical model is developed to predict needle temperature. The predicted needle temperature is compared with the experimental results by the inserted thermocouple method. Some of the process parameters, used as input variables, were also measured experimentally and experimentally observed values of needle temperature were compared with the theoretical prediction. It was observed that the temperature of the needle increases significantly with the presence of the sewing thread. Both the theory and the experimental results show that the needle temperature increases linearly with the machine speed within the ranges studied.
This study investigates the effect of material composition on moisture management properties. Fiber type has significant influence on the moisture management properties of knitted fabrics. In this article, single jerseys knitted fabric samples with different yarn compositions were prepared. Liquid moisture transportation properties including wetting time, absorption rate, spreading speed, one-way transportation capability, and OMMC were evaluated by Moisture Management Tester (MMT) and vertical wicking was evaluated using thermography system and image analysis. Knitted sample having fine cotton yarns with coolmax and micro denier multifilament polypropylene showed best liquid transportation properties. There is a strong co-relation between OMMC and accumulative oneway transport index with vertical wicking of knitted samples.