Thesis Details

Thesis Title: Determination of the effects of fabric construction and fabric speed on interchange factor for the wet-on-wet pad batch dyeing of 50/50 polyester cotton single jersey knitted fabric
Thesis Author: Christopher Moses
Abstract: Padding processes are commonly used to apply solutions to fabric. These processes are typically classified as wet-on-wet or wet-on-dry. In a wet-on-wet process, solution is padded onto a wet fabric, while a wet-on-dry process uses a dry fabric. When the solution concentration on the fabric is considered critical, fabric is typically fed to the pad in a dry state. Drying a fabric before padding eliminates the possibility of dilution of the pad bath by water from a wet fabric. However, the drying process increases processing cost, can damage the fabric, and can limit plant production. It is possible to eliminate bath dilution in a wet-on-wet process by feeding the chemical solution into the pad at a higher concentration than that of the initial pad bath. The rate at which water from the wet fabric is exchanged with the pad bath is needed to calculate the pad bath reconstitution stream concentration needed for equilibrium. The rate of exchange can be characterized by a parameter called the interchange factor. This thesis studied the effects of twist multiple, cotton count, loop length and padding speed on interchange factor for a wet-on-wet padding process. A 50/50 polyester/cotton single jersey tubular knitted fabric constructed from ring spun yarn was used in this study. Increases in processing speed and cotton count, and decreases in stitch length typically resulted in decreases in interchange values. Increases in twist multiple affected interchange differently at different stitch lengths. It was determined that correlations between interchange factor and pickup difference, air permeability, and fabric weight existed.