Thesis Details

Thesis Title: Turn-Over Rate and Liquor Ratio: Effect on Dye Shade Repeatability in Jet Dyeing
Thesis Author: Michael Costello
Abstract: In the past ten years batch dyeing processes have become more popular because of the increased demand for shorter lots of different style fabric. One of the most versatile of the batch dyeing processes is jet dyeing. Today, there is a wide range of jet dyeing equipment available which can dye polyester fabrics at high temperature and pressure, as well as dye cotton and other fibers at atmospheric conditions. Because of its versatility the jet has become one of the most popular of the batch dyeing machines. with the introduction of Quick Response and Just-inTime to the textile industry, more odd size lots are being run in jet dyeing equipment. Fabric loads in jets can be varied up to fifty percent in production. This change in load size is often made without regard for changes in liquor ratio and turn-over time. If these variables influence dye shade then variability in dye shade may be increased when changing lot size. with the introduction of Just-in-Time production, tighter control of shade is now being expected from our dye houses. Therefore control of all variables the could influence dye shade has become more and more important. In this thesis four series of experiments were designed to determine the influence of liquor ratio and turn-over time in disperse dyed polyester and reactive dyed cotton fabrics. Liquor ratios and turn-over times were varied and measurements of KIS, Delta E*, and % Exhaustion were then used to determine the influence of these variables on dye shade repeatability. The results of this work showed that liquor ratio influences dye shade in both polyester and cotton fabrics. Turn-over time was found to be less significant, however, a minimum amount of dwell time is necessary in the dye liquor to maximize dye yield in the case of reactive dyed cotton fabrics. From this research it is recommended that more attention be placed on controlling liquor ratio as closely as practical when changing lot sizes in production jet dyeing.