What is Dyeing (Denim Fabric Process)?
It is an ancient process, with evidence of dyed fabric dating back as far as the Neolithic era. The most basic method of dyeing involves simply dipping the material into a hot dye bath and allowing the fibers to absorb or bond with the dye until the desired color is reached. However, there are often steps performed beforehand to prepare the fiber to absorb the dye such as scouring, bleaching, and mordanting.
There are two main types of dyes: natural and synthetic. Natural dyes are derived from plants, animals, or minerals and produce more subdued colors than synthetic dyes. Examples of natural dyes include henna, saffron, and, of course, indigo. Synthetic dyes, first discovered in 1856, are dyes derived from chemicals. The majority of textile manufacturers today use synthetic dyes as they are cheaper to produce and offer a wider and more vibrant range of colors. Denim is dyed with either natural or synthetic indigo using one of a variety of methods such as garment dyeing, hank dyeing, rope dyeing, and yarn dyeing/Slasher dyeing.
Different Dyeing Methods For Yarn
1. Slasher Dye
Its an indigo dyeing method for yarn
Slasher, or sheet, dyeing combines dyeing and sizing into a single process. Warp yarns are repeatedly passed in warp beam form through several baths of indigo dye before being sized and wound for weaving.
Slasher dyeing is considered to be lower quality than rope dyeing – the dye does not penetrate well and the color tends to be uneven. However, recent mechanical improvements have helped make it a more viable option.
2. Rope Dye
Believed to be the best possible indigo dyeing method for yarn, the threads of denim yarn are initially twisted into a rope, then undergo a repetitive sequence of dipping and oxidization. The more frequent the dipping and oxidizing, the stronger the indigo shade.
Rope dyeing consists of twisting the yarns into a rope that is then quickly dipped into indigo baths. It is considered the best method for dyeing denim as the short dyeing time does not allow the indigo to fully penetrate the fibers, thus creating ring-dyed yarn that fades better and faster than fully dyed yarn.
(Published by Heddels)
