جستجوی مقالات مرتبط با کلیدواژه « dyeing kinetic » در نشریات گروه « مهندسی شیمی، نفت و پلیمر »

In this study, dyeing kinetics of the poly(ethylene terephthalate) (PET) interlaced bi-shrinkage and normal textured yarns were considered. The dyeing processes were carried out using C.I. Disperse Blue 183 at different times and temperatures. The experimental data were adjusted to well-known dyeing kinetic equations, i.e. Vickerstaff, Patterson, McGregor and Cegarra-Puente to determine the constant rate of dyeing and diffusion coefficient at different temperatures. The results showed that the exhaustion, constants rate of dyeing and diffusion coefficients were increased with increasing the time and temperature of dyeing process for both normal and interlaced bi-shrinkage PET yarns. Also in all similar dyeing times and temperatures, the exhaustion values and diffusion coefficients of interlaced bi-shrinkage PET yarns are higher comparing to normal PET yarns. The turning point of the exhaustion curve for the BSY PET yarn significantly was decreased (-50%) with increasing the dyeing temperature from 120 oC to 130 oC. Also activation energy of conventional PET yarn was observed 22.3% more than BSY PET yarn. The best adjustments of the both normal and interlaced bi-shrinkage PET yarns with applied dyeing kinetic equations were observed for the Vickerstaff equation.

In this study, kinetic behavior and dyeability of woolen yarns with madder and cochineal natural dyes were investigated. Dyeing rate was separately calculated for each dye at different times and temperatures. Results showed Patterson’s rate equation as the best model to describe dyeing rate in which rate constants in the range of 0.0031-0.0341 and 0.0024-0.0318 were obtained for cochineal and madder, respectively. Dyeing temperature had essential role on kinetic behavior and with the increase of temperature, dyeing rate and equilibrium time increased. Cochineal demonstrated better dyeability on wool than madder. Saturation point on wool was achieved using 20% and 60% owf of cochineal and madder dyes, respectively. Diffusion coefficient values at different temperatures were calculated from Hills’ equation, and it was found that temperature had key role on diffusion values. As temperature raised from 30 to 95 °C, diffusion coefficients increased from 0.83×10-11 to 7.4×10-11 in the case of madder and from 1.02×10-11 to 11.32×10-11 in the case of cochineal dye. Overall, the results of this study confirmed better dyeing performance, higher rate constant and diffusion coefficient for cochineal on wool compared to madder.

In this investigation, dyeing kinetic of modified PP fibers produced as polypropylene polybuthylene terephthalate (PP/PBT) polyblend fibers was studied. The modified fibers were dyed with selected disperse dye (C.I. Disperse Blue 56) at different times and temperatures. The experimental data was adjusted to well-known dyeing kinetic equations, i.e. Vickerstaff, Patterson, McGregor and Cegarra-Puente to determine the rate constant of dyeing and diffusion coefficient at different temperatures. The results showed, exhaustion, constants rate of dyeing and diffusion coefficients, were increased with increasing the time and temperature of dyeing process. A significant enhancement in dye absorption was observed for dyeing in 120 oC compare with other temperatures. So that, the time of dyeing saturation was reached two times faster in this dyeing temperature compare to the other temperatures. The best adjustments with applied dyeing kinetic equations were occurred with the Vickerstaff and Cegarra-Puente kinetic equations. However, the Vickerstaff equation was determined as the best model with regard to their highest average regression coefficients and suitable trend of dyeing kinetic constants in the range of the dyeing temperatures. Diffusion coefficient value was increased significantly (9 times) by increasing the dyeing temperature. Furthermore, the highest variation of diffusion coefficient enhancement belongs to temperature variation from 100 oC to 120 oC. Also, trend of the diffusion coefficients showed a good conformity with the exhaustions trend in the different temperatures. J. Color Sci. Tech. 7(2013), 165-172©. Institute for Color Science and Technology.