Paddyeing

Pad-dyeing, often written paddyeing in some texts, is a continuous dyeing process used in textile finishing to color fabric. It relies on a padded application in which fabric is passed through a dye liquor and then squeezed by rollers to control liquor uptake. The fabric is subsequently dried and heat-fixed to set the color.

Process and sequence: The fabric enters a padder where dye liquor containing fixing auxiliaries is pressed into the fibers by nip rollers. The liquor pickup is expressed as a percentage of the fabric’s weight. After padding, the fabric moves to a dryer to remove moisture, then to a fixation stage such as steaming or thermal fixing to set the dye, and finally to washing and finishing.

Equipment and configurations: Pad-dyeing systems include open-width and tubular padder lines, followed by drying and fixation units. Some lines integrate a steamer or heat-setting chamber and a continuous washer. The equipment is designed to ensure uniform penetration and consistent shade across the fabric width.

Dyes and fabrics: Pad-dyeing is commonly used for cellulose fibers (e.g., cotton, viscose) and their blends, employing reactive or vat dyes. It can also accommodate certain synthetic fibers with appropriate dye chemistries (e.g., disperse dyes for polyesters, where suitable carriers or process adjustments are used). The method supports solids and uniform shades on wide ranges of fabric types.

Advantages and limitations: Advantages include good color uniformity, controllable shade depth, and suitability for continuous production and small-to-medium batch runs with reduced liquor handling. Limitations involve the need for careful process control over liquor pickup and fixation, equipment costs, and restrictions related to dye compatibility with specific fibers and finishes.