Methods of Dyeing

There may or may not be a full penetration of the colourant into the fibres or yarns during the dyeing process, which involves adding colour to fibre stock, yarn, or fabric. Only if dyes have an affinity for them can they be applied to fibres produced by plants, animals, or men. Acid dyes, which are mostly used to dye wool, silk, and nylon, as well as direct or substantive dyes, which have a strong affinity for cellulose fibres, are examples of textile dyes. To give mordant dyes an affinity for the material being coloured, chemical additives like salts are necessary. After the cellulose fibres, wool, or silk have been treated with metal salts, they are applied to those materials. While cheap, sulphur dyes, which are used to colour cellulose, generate dull colours.

What is the Meaning of Dyeing?

Dyeing simply means coloring the fabrics with different colors. The methods and types of dyeing vary and depend upon the quality of fabric and choice of the person. Azoic dyes are insoluble pigments that are created inside the fibre by padding it with a diazotized base first and subsequently with a soluble coupling chemical. Vat dyes, which are soluble only in alkaline solutions of sodium hydrosulfite, are transformed into soluble colourless molecules.

These colourless substances are taken up by the cellulose and oxidised into an insoluble pigment after that. They are dyes that are colorfast. Insoluble organic pigments that are finely dispersed are called disperse dyes, and they are used to colour hydrophobic fabrics like polyester, nylon, and cellulose acetate. Reactive dyes have exceptional colorfastness because they interact directly with the cotton. In the middle of 1950, the first collections of reactive dyes for cellulose fibres were released. There are several options available today.

Types of Dyeing

The following are the various types of dyeing.

Bale Dyeing

This is a cheap way to colour cotton fabric. The material is put through a cold water bath where the warp has an affinity for the dye without being scourged or singulated. This kind of dying is frequently used on imitation chambray and related materials.

Chain Dyeing

When the tensile strength of yarns and fabrics is low, this is utilized. Cuts or pieces of cloth are sewn together end to end and threaded through in a continuous chain in the colour of the dye. This approach allows for high production.

Cross Dyeing

This is a very common technique that produces a variety of colour effects in a single dye bath for fabric made of fibres with different dye affinities. For instance, a blue dye may give nylon 6 a dark blue shade, nylon 6 a light blue shade, and have no inclination to turn polyester areas white or unaffected.

Batik Dyeing

This is one of the earliest forms of life on Earth. It came from Java. Wax is applied to certain regions of the fabric to prevent the wax-coated portions from absorbing the color. The technique can be repeated several times with different colour combinations to achieve the strange effects. Machine printing mimics the muddled, mottled, or streaked appearance of patterns.

Beam Dyeing

Prior to weaving, the warp is coloured using this technique. The yarn is dyed by having the dye driven through perforations in a perforated beam onto which it has been coiled.

Jig Dyeing

This is carried out with the commodities in an open arrangement in a jig, kier, vat, beck, or vessel. The fabric is passed through several rollers in a deep dye bath in order to create the required hue.

Piece Dyeing

Piece dyeing is the process of dying fabric in cut, bolt, or individual piece form. It gives a single colour for the fabric, such as blue serge or green organdy, and follows the weaving of the items.

Burl or speck Dyeing

The majority of the time, woollen or worsted fabrics are used for this. Special coloured links, which come in a variety of colours and shades, are used to cover coloured blemishes and specks. It is a manual process.

Raw Stock Dyeing

The fibre material is dyed before it is spun into yarn. Wool fibres are degreased, and the stock is dried before dyeing.

Solution Dyeing

The pigment colour is bonded into the solution and taken up as the filaments are generated in the liquor; this process is also known as dope dyeing or spun dyeing. Using this technique, both cellulosic and non-cellulosic fibres can be coloured to perfection. Bright, crisp, quick, and clear colours are used.

Yarn dyeing

Following the spinning of the yarn comes yarn that has been coloured before being woven into the items. It can be carried out with either partial or complete immersion of the yarn.

Random Dyeing

Only certain selected areas of the yarn are colored. This style of colouring can be done in one of three ways. Skeins may be firmly dyed in two or more locations and dyed with one colour on one side and a different colour on the other. The skeins that are stretched out on the printing machine’s blanket cloth can be printed in colour. Cones or packages of yarn on hollow spindles may be arranged to create channels through which the yarn and dyestuff are pushed through these holes by suction using an air-operated punch. The dye is absorbed by the yarn close to the punch, which results in the desired random effects.

Conclusion

To conclude, most commonly, dyes are used to colour, embellish, and clean items like wood, food, and hair, in addition to other things like textiles. Due to the differences in qualities of dyes, different dyes are used for various materials. Also, different types of dyes are used to colour textile products. Understanding the many types of dyes used to colour textile products is crucial. Different dyes have various characteristics. According to the materials, dyes function. Therefore, many dye classes are utilised in the textile industry to colour textile products.