Thesis Details

Thesis Title: Identification of dyeing methods for reducing the effect of barre in fabrics containing false-twist textured polyester yarn
Thesis Author: Chasity Allen
Abstract: The production of manmade fibers has increased continuously since 1981. Polyester is one synthetic fiber that is produced in large quantities, with polyester filament holding 39 % of the manufactured fiber market. There are two primary methods for the texturing of filament yarn that are used today, false-twist and air jet texturing, with false-twist texturing comprising nearly 60% of the textured yarn market. Although false-twist textured yarn is used in both woven and knitted goods, neither is free from problems. The most prevalent problem is that of barre in dyed knitted fabrics made from textured filament yarns. The purpose of this research was to determine which texturing parameters have the most effect on dye uptake, and to develop a suitable dyeing method to reduce the effect of barre. It was determined that heat-setting fabrics at 180 °Celsius/356 °Fahrenheit produced overall smaller average differences in dye depth from a standard than fabrics heat-set at 200 °Celsius/392 °Fahrenheit. Also, it was concluded that scouring temperature does not have an effect on reducing dye differences. Of the three dyeing temperatures evaluated, the highest dyeing temperature of 140 °C/286 OF, was most successful in reducing dye differences. Furthermore, it was determined that the leveling agents evaluated reduced the shade depth differences overall. It was ascertained that dye uptake is primarily affected by heater temperature and draw ratio at texturing. As a result, it is imperative that texturing operations closely monitor heater temperature and draw ratio during the texturing process.