How are dyes classified on the basis of their application?

Dyes may also be classified by their method of application to the substrate. Such a classification would include direct dyes, reactive dyes, vat dyes, disperse dyes, azoic dyes, and several more types.

What are dyes and its classification?

A. acid dyes, natural dyes, basic (cationic) dyes, synthetic dyes, direct (substantive) dyes, disperse dyes, sulfur dyes, pigment dyes, mordant dyes, vat dyes, reactive dyes, macromolecular dyes, metallized dyes, naphthol dyes, premetallized dyes, gel dyeing, developed dyes, azo dyes, aniline dyes, anthraquinone dyes.

What are dyes and its applications?

dye, substance used to impart colour to textiles, paper, leather, and other materials such that the colouring is not readily altered by washing, heat, light, or other factors to which the material is likely to be exposed.

What are the application of dyes on textile?

Textile dyes include acid dyes, used mainly for dyeing wool, silk, and nylon; and direct or substantive dyes, which have a strong affinity for cellulose fibres (see table). Mordant dyes require the addition of chemical substances, such as salts, to give them an affinity for the material being dyed.

What is the classification of solubility dyes?

some cases, based on the solubility, dyes are classified differently. As an example, acid, basic, direct, mordant, and reactive dyes are considered as soluble dyes. Whereas azo, disperse, sulphur, solvent, and vat dyes are some examples of the insoluble dyes, as depicted in Fig.

What are the application of natural dyes?

Natural dyes find use in the colouration of textiles, foods, drugs, and cosmetics. Small quantities of dyes are also used in colouration of paper, leather, shoe polish, wood, cane, candles, etc. In the earlier days, dyes were derived only from natural sources.

What are the application of pigments?

Pigments are used for coloring paint, ink, plastic, fabric, cosmetics, food and other materials. Most pigments used in manufacturing and the visual arts are dry colorants, usually ground into a fine powder. This powder is added to a vehicle (or matrix), a relatively neutral or colorless material that acts as a binder.

What are characteristics of dyes?

A dye has the following characteristics:
  • It must have a suitable colour.
  • It can be fixed on the fabric either directly or with the help of mordant.
  • It must be resistant to the action of water, acid and alkalies. The groups responsible for colour are called chromophores.
  • These should be unaffected by light.

What is dye in organic chemistry?

With regard to their solubility, organic colourants fall into two classes, viz. dyes and pigments (Allen 1971). The key distinction is that dyes are soluble in water and/or an organic solvent, while pigments are insoluble in both types of liquid media. Dyes are used to colour substrates to which they have affinity.

Why are dyes categorize into two major classification natural and synthetic?

Dye Classification

Broadly, dyes can be classified into natural and synthetic based on the source of origin. Natural dyes can be extracted from natural sources such as fruits, flowers, leaves, roots, barks, etc., whereas synthetic dyes are synthesized in laboratories by the use of chemicals.

What are the properties of dye?

Dyes are generally soluble in water while pigments are almost insoluble in water. Dyes are available in large number in the market while the number of pigments is very less. Dyes impart colour by selective adsorption while pigments adsorb colour either by selective adsorption or by scattering of light.

What are basic dyes?

Basic dyes are water-soluble cationic dyes that are mainly applied to acrylic fibers, but find some use for wool and silk. Usually acetic acid is added to the dye bath to help the uptake of the dye onto the fiber. Basic dyes are also used in the coloration of paper.

What are organic dyes examples?

Abbey Color supplies five organic dyes / natural dyes: logwood, walnuts crystals, fustic, brazilwood and hematine. While synthetic materials can offer longer lasting color in a wider range of options and a wider range of materials, natural and organic dyes provide exactly what they say they do.

How many types of natural dyes are there?

There are two types of natural dyes. Adjective or additive dyes such as madder must use a mordant (a chemical that fixes a dye) to bond with fibers. These are the most common type and have been used for at least 2,000 years.

What are direct dyes used for?

Direct dyes are used on cellulosic fibers when good lightfastness is needed, but washfastness is not critical. This includes window coverings, upholstery, and heavy bedding where the finished item is seldom washed or is labeled as dryclean only.

What is the difference between acidic and basic dyes?

Acid dyes are water-soluble anionic dyes mainly used on fibers such as wool, silk, and nylon. Basic dyes are water-soluble cationic dyes mainly used on acrylic fibers. Direct dyes are used on natural fibers such as cotton, linen, cellulose and in special treatments such as dip dyes.