Characteristics of Natural Dyes and importance &Types

What is Natural Dyes:

The word ‘natural dye’ refers to all the dyes derived from the natural sources. Its mainly obtained from different plants, animal and minerals resources. It is mostly non-substantive and must be applied on textiles by the help of mordant. Ancient humans used root, wood, bark, grass, berries, leaves, nuts, seeds, flowers as natural dye. Throughout civilization, humans gradually invented hand spinning and hand loom weaving for making cloths. People were imparted different colors on cloth in order to develop designs and differentiate clothing from one another. Textile clothing and apparel materials are used to be colored for value addition, look, and desire to the customers.

Eco-Friendly natural dyes:

Natural dyes are broadly considered to be more Eco-friendly than synthetic dyes. The reasons are obvious: earthbound elements combine with sustainable production techniques. If these dyes do end up in waterways, at least we know they’re not going to corrupt the entire ecosystem. However, though the dyes themselves may have an entirely organic composition, they can be bound to clothing fibers through artificial chemicals, called mordant. These are metal oxides that combine with dyes to help them adhere to fabrics. Another sustainability issue with natural dyes is that they can involve higher water use than conventional dyes. Even so, should innovation allow it, natural dyes could take the fashion world in a slower, safer, and more sustainable direction.

Characteristics of Natural Dyes:

Natural dyes are organic and are derived or extracted from resources found in nature. Natural dyes are mostly Eco-friendly, biodegradable, less toxic, and less allergenic as compared to synthetic dyes. However, studies have shown that certain natural dyes may have detectable mutagenic effects e.g., elderberry color and safflower yellow; others, like carmine, can cause asthma by continuous inhalation.

• Natural dyes are safer from synthetic dyes and since it does not contain harmful chemicals there is a very low possibility for causing skin allergies. Mostly all plant dyes are safe to be worn.
• Natural dyes are bio-degradable; therefore, it does not harm the water ecosystem when drained into water bodies.
• Natural dye tends to fade easily, so for making the dyes stick to the fabric dye fixative are used, this can be in the form of starch, seaweed, Alum (hydrated double sulfate salt), table salt, vinegar.
• Fabrics dyed with natural dye are more delicate and have to be handled with care, it should not be dried directly in sunlight.

Types of Natural Dyes:

There are three types of natural dye which must be applied in fabric with appropriate technique. These are as follow:

1. Plant dyes: obtained from leaves, flower, skins of fruit, bark, roots, wood etc.
2. Insect Dyes: obtained from various dried bodies of insects.
3. Animal Dyes: obtained from created from shellfish Carmine, Cochineal and so on.

Natural Dyeing Process:

For successful commercial use of natural, the appropriate and standardized dyeing techniques have to be adopted for particular fiber. However, the modern natural dyeing process information is very insufficient. That is why an attempt has been made here to give a scientific overview of the dyeing process.

 Scouring:

Scouring is the first procedure for any dyeing process. Raw fabrics and yarns carry impurities and residues such as: dirt, wax, dust, coatings. If the fiber is not properly scoured, the dye will adhere to the coating of residue, instead of the fiber itself. The colors will not fully penetrate, and the fabric will dye unevenly. In scouring process, fibers submerging in water along with a scouring agent. Water temperatures, pH and scouring agents vary depending on fiber. Generally, soda ash or neutral soap uses for plant fibers such as cotton, jute, flax, etc. And orvus paste soap used for protein fibers like: silk and wool, etc. Plant fibers will simmer in the bath for a few hours. But protein fibers are sensitive to higher temperatures, so they need to be handled more carefully.

Mordanting:

Mordant makes a bond between the fiber and the dyestuff. So this step is very important in the dyeing process. Mordanting is most effective if it’s done before the dyeing process. But some manufacturer prefers to combine the mordant and dyestuff in one bath. While it’s possible to dye fibers without a mordant, but it will not achieve a durable, long-lasting color without a mordant. Mordanting is the process of wetting fibers in hot water with a diluted mordant for at least one hour. But it can, let the fibers cool in the solution overnight to ensure maximum color-fastness.

Dyeing:

Powder dyes and extract dyes are concentrated and ready for application in the fabric. But foraged ingredients like fresh plants, insects, flowers, fruits, or roots need some preparation before the dyeing. After the dye materials are ready to go, it’s time to decide to choose a technique that will apply to the fabric. There are different kinds of traditional techniques available. For solid color, the general-submersion method could be applied. Other techniques including ombre (dip-dyeing), bundle dyeing, shibori dyeing, and the like techniques are available to dye the fabric.

Advantages of Natural Dyes:

Natural dyes are recommended to be applied on textile materials. The natural dyes have several advantages such as: these dyes need no special care, wonderful and rich in tones, act as health cure, have no disposal problems, have no carcinogenic effect, easily biodegradable, require simple dye house to apply on matrix and mild reactions conditions are involved in their extraction and application. Following points support the use of natural dyes on a large scale.

1. Eco-friendly: Natural dyes are extracted from natural sources therefore they are environment safe.
2. Biodegradable: These dyes are capable of being decomposed by microorganisms.
3. Renewable: Replaced by the new material obtained from nature.
4. No health hazard/Non-toxic: Natural origin of these dyes makes them harmless.
5. Variety of shades: Varieties of color, shades and hues present in nature itself.
6. Soothing, soft and lustrous color: Natural dyes are soft and relaxing.
7. Utilization of waste material: Many agriculture waste products can be used in the dyeing process.
8. Antibacterial/UV Protective: Naturally dyed fabrics get special properties like antibacterial and UV protection.

Why Natural Dyeing is Important?

Today global demand for natural dye in the coloration of textiles products is nearly 0.1 million tonnes, which is equivalent to 1% only of the world’s synthetic dye consumption. Almost every synthetic colorant being synthesized from petrochemical sources. As a result, hazardous chemical dye processes pose threat to its Eco-friendliness. Worldwide growing consciousness about organic Eco-friendly products has generated renewed interest of consumers towards the use of textiles dyed with Eco-friendly natural dyes. Natural dyes are known for its uses in the coloring of food substrate, leather and natural fibers. It was being applicable since Pre-historic times. Even after a century, the uses of natural dye never erode completely. Thus, natural dyeing of different textiles has been continued mainly in the decentralized sector for specialty products; besides the use of synthetic dyes in the large-scale sector for general textiles. But natural dye processes are not yet ready for industrial production. We have to make more and more research to make sustainable large production in the textile industry.

Conclusion:

Natural dyes produce an extraordinary diversity of rich and complex colors that complement each other. Dye extracts may look a little expensive at first, but they are very economical when their concentration has been taken to account. So much of work has already been done on most of the old dyes that the need of newer dye sources has emerged to keep alive the use of these dyes. Many scientists/researchers are doing a great deal of work in the area of amelioration of natural dye, and this period can be considered as the renaissance of natural dyes. The increasing knowledge of different natural sources providing beautiful colors is expanding the shade cards of different fabrics. Revamping of this ancient art has another distinctive attribute, that is, the empowerment of such tribes that used to thrive on this form of art.