A Low-Cost Colorimetric Sensor Using Optical Transmission for Real-time Control of Textile Dye Bath Exhaustion

摘要

The temperature is often the principal variable taken into account to control the exhaustion of the dye bath. This exhaustion is influenced by various factors such as: the temperature of the bath, pH, the salinity of the bath, duration, concentration of the dyes. However, the goal is not to control temperature per se, but to control the final color and strike (rate of dye uptake). Therefore, if one could control or predict the exhaution profile during dyeing, one could control the amount and rate of dye uptake onto the fabric. The difficulty is in the measurment of the dye concentration deposited onto the fabric. For this reason, the design of a low cost colorimetric sensor, enabled us to approach the field of the textile dyebath control with minimum investment (i.e., without expensive spectrophotometer). This sensor is based on Beer’s Law (with transmission by optical fibre). A luminous flow is introduced into a measuring chamber where circulates permanently the textile dye bath. At the exit, the light flow is analyzed by four filters so as to cover all the spectrum of the visible light. A system of real-time data acquisition is developed. Results and test on single dye and mixture of dyes are encouraging.