Dyeing Studies at Elevated Temperatures

Abstract

An apparatus has been built for dyeing textiles in the temperature range of 200°F to 300°F and fundamental dyeing data have been obtained using a wide variety of textile fibers. The high- temperature technique is particularly applicable in the dyeing of those fibers which require a long time for the diffusion of the dye into the individual fibers when it is applied under normal dyeing conditions. The high-temperature technique increases the speed of dyeing to such an extent that dyeings which normally require hours can be produced in a matter of seconds. Commercially acceptable dyeings have been made on wool and wool-cotton unions in less than 90 seconds at 270°F. In general, it can be stated that because of the short periods of contact at these high temperatures the same extent of dyeing can be obtained without any greater change in the tensile characteristics than is obtained when an equivalent dyeing is carried out for a longer time at lower temperatures. The amount of thermal decomposition of a large number of dyes was determined, and a number which are suitable for high-temperature dyeing have been selected. A method for the application of dyes by padding and then developing at elevated tempera tures has been worked out; this method, owing to the increased speed of dyeing, makes it prac tical to dye continuously at a rapid rate many fabrics which previously have not been dyed by a continuous process.