Sulfur dyes are the most commonly used dyes manufactured for cotton in terms of volume. They are cheap, generally have good wash-fastness, and are easy to apply. Sulfur dyes are predominantly black, brown, and dark blue. Red sulfur dyes are unknown, although a pink or lighter scarlet color is available.
Sulfur dye is generally heated sulfur or sodium sulfide together with certain aromatic amines, amino phenols and other organic compounds, namely vulcanization. In dyeing, sulfur dye needs to be dissolved in a sodium sulfide solution or alkaline hydrosulfite solution to reduce to its hidden color, and then absorbed and oxidized by fiber to show color.
· Sulfur dyes are commonly used for black, blue, brown, khaki and green colors.
· Sulfur dyes are applied to cellulosic fibers and blends of cellulosics with polyester, nylon and acrylics.
· Sulfur dyes can be applied with little difficulty and with excellent results at a relatively low cost.
Sulfur dyes are high molecular weight compounds that are obtained from the reaction of sulfur or sulfides with phenols and amines. There are many colorants available in the market that contain sulfur however, only those dyes that are soluble in water after reacting with sodium sulphide in alkaline conditions are known to be sulfur dyes.
Sulphur Black dye is available in powder, granules and liquid form, having high degree of properties than other cotton dyes available in market. Good color fastness properties such as light fastness, wash fastness and cost effectiveness makes Sulphur black an important class of dye. This dye can be applied on garment, fabric by exhaust, semi continuous or continuous dyeing methods.
