Abstract A novel composite yarn was prepared by simple sizing coating using polyester (PET) as core yarn and polyvinyl butyral (PVB) and zirconium carbide (ZrC) suspension as slurry. The scanning electron microscope results revealed the core–shell structure of the composite yarn and ZrC particles deposited on surface coating successfully. The maximum near‐infrared absorption rate of the fabric made of PET/PVB/ZrC composite yarn reached 96.42%. The test showed that when exposed to infrared light (dominant wavelength 950 nm), the surface temperature of the composite yarn rose more quickly than that of pure PET yarn. The photothermal conversion property of the composite yarn reached the best when PET yarn was treated in 4 wt% PVB solution with 5 wt% ZrC content. The composite yarn also exhibited good light‐to‐heat performance in real environment. In addition, PVB/ZrC coating provided the composite yarn excellent ultraviolet (UV) protection (UPF 50+) and produced little effect on thermal stability. Durability tests of PET/5%PVB/4%ZrC composite yarn verified pretty good washing resistance of near‐infrared absorption and UV protection properties of the composite yarn. This work provides a simple and economical method for preparing multifunctional composite yarn.
As a functional textile, photothermal textile materials are receiving more and more attention. A composite yarn was prepared by coating polyvinyl butyral/zirconium carbide/alumina oxide on the surface of polyester yarn through a sizing coating method with the aim to provide a textile substrate with controlled photothermal efficiency. The Box–Behnken design combined with response surface analysis and regression method was used to study the effects of input variables (polyvinyl butyral, zirconium carbide and alumina oxide concentration) on the temperature of the fabric made of polyester/polyvinyl butyral/zirconium carbide/alumina oxide composite yarn under infrared light irradiation. It was found that the effect of polyvinyl butyral and zirconium carbide content on the fabric surface temperature was more significant than that of alumina oxide content. The established regression model could predict the response value (fabric temperature) precisely. The optimal conditions for preparing the polyester/polyvinyl butyral/zirconium carbide/alumina oxide composite yarn were obtained by response surface analysis: 5.9% polyvinyl butyral, 5% zirconium carbide and 0.5% alumina oxide. The structure and properties of the yarn prepared under the optimal conditions were characterized. The results showed zirconium carbide and alumina oxide deposited on surface coating without obvious deterioration of thermal stability and tensile strength. The near-infrared light absorption rate of the composite yarn reached 96.71% and its surface temperature reached 104.0°C after 180 s irradiation under an infrared lamp. The photothermal temperature can still reach 101.5°C after 20 cyclings. The excellent photothermal conversion capacity indicates the polyester/polyvinyl butyral/zirconium carbide/alumina oxide yarn can realize solar energy utilization and be applied in heat management textiles.
The formaldehyde-free crease-proof finishing agent 1,2,3,4,-butanetetracarboxylic acid (BTCA) was used to treat lyocell fabrics. The effects of BTCA concentration and curing temperature on the wrinkle recovery angle (WRA) and tensile breaking strength of lyocell fabrics were discussed. The results showed that with the increase of BTCA concentration and curing temperature, the WRA value of lyocell fabrics increased obviously and the maximum WRA reached 147°, but breaking strength decreased gradually and the minimum strength retention was 68%. The WRA was durable against laundering. The fabric whiteness difference was not obvious and the whiteness retention of all samples exceeded 98%. After further alkali treatment, the WRA of the treated lyocell fabrics decreased and the fracture strength retention recovered to varying degrees (0.45–10.8%). The developed regression equations were found to be in good correlation ( r 2 > 92%) with the selected variables (tensile strength, BTCA concentration, curing temperature). Fourier transform infrared spectroscopy analysis confirmed that the tensile strength loss of BTCA-treated lyocell fabrics was caused by cross-linking of cellulose molecules and acid degradation. Tensile strength loss that resulted from ester bonding could be restored after hydrolysis in alkaline solution. The recoverable magnitude of tensile strength was related to the curing temperature. A high temperature not only promoted the cross-linking of cellulose macromolecules, but also accelerated the acid degradation of cellulose.
Based on the analysis of rainfall distribution law of typhoon storm or thunderstorm, a real-time flood forecasting model considering rainfall center is proposed by absorbing the advantages of Isohyetal method and Thiessen polygon method. In accordance with the rainstorm data of 14 floods in Nanxi River Basin from 1990 to 2004, the forecasting accuracy of two methods considering rainfall center and without considering rainfall center are compared. The results show that the former strengthens the peak-building effect of rainstorm center and improves the real-time flood forecasting accuracy.
PAN/PEG/CNT/cotton composite yarn (PPCCY) was fabricated by impregnating PEG2000–10000 into CNT/cotton yarn (CCY) and coating electrospun PAN around its surface. The effects of PEG type on the morphology, structure, electrical resistance and phase change behavior of the produced composite yarns were studied thoroughly by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermal gravimetric(TG), electrical resistance tester and infrared thermal images. The experimental results indicated that the resulting compound yarn consisted of conductive yarn within which the spacing between cotton fibers was fulfilled by PEG, rendering phase transition enthalpy from 126–150 Jg −1 . The composite yarn exhibited adjustable temperature and thermal storage and electrical conductivity abilities. The composite yarn demonstrated good responsive properties to external electrical and thermal stimuli and had reversible heat conversion and storage, which shows a promise for applications in electrical wearable fabrics.
Polyaniline (PANI) is one of the most important conducting polymer and has been widely used in various fields for its tunable electrical conductivity. In this manuscript, conductive polyaniline/ramie fabrics were developed by in situ polymerization and characterized. The effect of aniline content, polyetherimide (PEI) pretreatment, padding and the color depth (K/S value) on electrical resistivity was analyzed. The result showed that electrical conductivity was increased with the increase of aniline (ANI) contents. PEI pretreatment and padding method improved the conductivity of the fabric significantly. The result of K/S value was reversely consistent with the conductivity. Both scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis confirmed that polyaniline particles were successfully deposited on the surface of the ramie fabrics. Thermal degradation (TG) measurement showed that polyaniline (PANI) polymerization decreased the onset decomposition temperature. Mechanical measurement showed that pretreatment process reduced the tensile strength of conductive ramie fabrics by 30%. K/S value in full range showed that the color of PANI/ramie fabric was sensible to pH value. Contact angle (CA) measurement disclosed the conductive PANI/ramie fabric was hydrophobic and this hydrophobicity was stable to the change of pH value. The obtained PANI/ramie fabrics can be used as potential conductive multifunctional textiles.
Nb Ti-IF steel with slight surface rust was used in hot-dip galvannealing experiments which were carried out in IWATANI hot dip process simulator( DHPS). The influence of substrate surface rust on annealed sheet and galvannealed coating were studied. The rust on the substrate turned into fine and porous reduced iron after being continuous annealed in the atmosphere of N2+ 5% H2.Due to the faster diffusion rate between the liquid zinc and iron at the rust areas during the galvannealing process,a thicker and flatter coating was formed,causing a white streaky mark defect.
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