Did you know that dyes also come in these many types?

We all have had our share of interaction with the term dye. Most of us think that dyes are just colouring substances providing colour to the product died. However, chemically a dye is a coloured substance that has affinity to the substrate on which, it is applied and thus imparts the colour to the substrate.
This article is all about the various forms this chemical compound is available in nature, and what the various industries in which they are used. Well, these chemical compounds are of various types and are classified as –

1. Acidic - these are generally water soluble and are used for fabrics like silk, wool, nylon, and polymeric compounds such as acrylic. The mechanism of action of such dyes is attributed to the anionic part of the compound, which leads to the bond formation with the cationic part in the fiber and thus contributes to the affinity of acid dyes. All the commercially used Synthetic food colorants fall under this category of dyes.
2. Basic – Basic dyes are just the opposite of acidic counterparts & applied mainly to the polymeric acrylic fibres. Acetic acid is also applied to increase the affinity of these chemicals. These are also commonly used in commercial coloration of papers.
3. Vat – water insoluble dyes, which do not have affinity for fibres directly fall under the category of vat dyes. But, commercial manufacturers reduce these chemicals in alkaline liquor, which results in the formation of alkali salts of these dyes. These salts can be used directly to dye textile fibres. The most commonly used vat dye is indigo that imparts blue colour to the denims that we wear commonly.
4. Reactive – unlike the other members, this dye makes use of an additional compound called a chromophore that directly interacts with the substrate and colours the fibre. The formation of covalent bond takes place; this is why such dyes are the most permanent of dyes used commercially. In fact, these are the first choice of dyers dealing with cotton and cellulose fibres.

Apart from these, other types include mordant, disperse, azoic and mordant dyes. There are also particular dyes used to impart darker colour to the cotton fibres. Such compounds fall under sulphur dyes and have been used commercially with a lot of success.
And all the above mentioned information gives you a good idea about the various types of dyes and their benefits that make them so important commercially.