| In recent years, a low rate of Right-First-Time success in dyeing and printing industry bring about some phenomena such as re-dyeing, color revising, waste-dyeing and color stripping in the process of dyeing, resulting in additional energy consumption and emissions. As an important type of synthetic fiber, polyester also faces with awkward situations in dyeing such as energy consumption and emissions sewage, so improving the rate of Right-First-Time success in dyeing of polyester becomes the focus of the dyeing and finishing workers. Establishing the mathematical model of the relationship between process factors and dyeing effect and dyeing dynamic model in the dyeing of polyester, studying the diffusion and adsorption mechanism in dyeing processes can make the prediction of dyeing effect and initial dyeing rate come true. Making some adjustments in process parameters to get better dyeing results and statistically controlling the dyeing process will improve the quality of products and the utilization ratio of dyestuff, then getting stable quality of products, improving the rate of Right-First-Time success in dyeing.We chosen three disperse dyes which were used for color matching:Disperse Red FB, Disperse Yellow M-4GL and Disperse Blue2BLN. The polyester fiber was dyed at high temperature and pressure. The optimum dyeing process was obtained through the single factor analysis of dyeing temperature, holding time and pH of dyeing solution. The optimum process was as follows:dyeing at130℃, holding for60min, pH=5.0and liquor ratio was1:50. The polyester can obtain high dye-uptake, K/S value and colour fastness when dyeing in the optimum dyeing process.On the basis of optimum dyeing process, the single and multiple factors models between process factors and dyeing effect were established by SVM theory which shows many special advantages in solving small sample nonlinear and high dimensional pattern recognition, and the predictions of dyeing effects by each model were made. It turned out that the errors between predictive values and the actual values were under3%, which shows that the mathematical model has high accuracy, it can exactly reflect the dye-uptake rate and K/S value in the dyeing process.Taking Disperse Red FB and Disperse Blue2BLN as examples, the dyeing kinetics of disperse dye on polyester were studied. Dyeing kinetics parameters (dyeing velocity K, half-dyeing time t and diffusion coefficient D) in the dyeing process were calculated, and dyeing dynamic model based on Hill formula and SVM theory were established as well. The calculation method and prediction effect of two models were compared, it was found that dyeing dynamic model based on SVM theory have a higher fitting degree, and it can easily reflect the actual situation in the dyeing process, so it can be used in practice. |
