Sulfur dye, Characteristics and Uses
Nowadays, there are many techniques applied to denim, and one of the most common is the sulfur dye, as its cost is low, it is easy to apply to this fabric and it has very good wash-fastness, this dye is mainly available in dark blue, black and brown colors, and there are some other not so common but used as well, such as pink, red or lighter scarlet colors.
“Sulfur dye is commonly used to give a good color to the garments made of denim, mainly because it gives a great appearance to the clothes and allows the buyer to note how the color stays for a longer time after several home laundries”, says Salomon Juan Marcos Villarreal, president of Grupo Denim.
The sulfur dye is water-insoluble, but it has to turn into a water-soluble one in order to apply it to the fibers, in order to do this, there is a chemical process to liberate hydrogen, which reacts with the dye, allowing the water molecules to attach to the sulfur dye, which is then transported into a cotton fiber helped by the water. When removing the hydrogen, the dye is basically insoluble, which would make it trap inside of the fiber, keeping the color of this dye on the garment for a longer time.
The sulfur dye is applied in cellulosic fibers, such as nylon, acrylics and polyester, and the most common colors are medium and dark, blue, black, brown, green and khaki. And one of the main advantages is that this dye is washed fast when it is applied with the right methods, although they are not easy to wash off with chlorine bleaching.
The sulfur black is oxidized in a better way when it is applied in air passage, such as Indigo, and it is commonly mixed with sulfur blue.
The cold dyeing of sulfurs is easy to apply on a full range of different colors in Indigo machinery, and this procedure is mainly used in Asia, where companies have been using it for years. While the cold dyeing of sulfurs is most preferred by some industries as it only require 50% of the sulfur dye, which means important saving of energy and environment care by less polluting dye waste, plus the excellent colorfastness offered by this product.
“The sulfur dye has many procedures used nowadays to create an entire range of different colors to the garments, helping to produce special colors to offer best options to the denim lovers which are looking for new colors on their clothes”, added Salomon Juan Marcos Villarreal.