Yaa Natural Dyeing Of Cotton Fiber Cloth Using Terminalia Chebula As Well As Turmeric Part-3

NATURAL DYEING OF COTTON FABRIC USING TERMINALIA CHEBULA (KADUKKAI) AND TURMERIC (CURCUMA LONGA) PART-3

Rajan.S¹
Textile Chemistry, SSM College of Engineering,
Komarapalayam, Namakkal, India.
srajusri321@gmail.com¹
Gopinath.M²
Textile Chemistry, SSM College of Engineering,
Komarapalayam, Namakkal, India.
gopi.tc007@gmail.com²

Previous Part


PRINCIPLE OF NATURAL DYEING
Most of the natural dyes convey no substantively on cellulose or other textile fibers without the occupation of a mordant. The bulk of natural dyes demand a mordanting chemic (preferably metallic element tabular array salt or suitably coordinating complex forming agents) to practise an affinity betwixt the fibre together with dye or the paint molecules of natural dyes. Aluminium sulphate or other metallic element mordant anchored to whatever fibre; chemically combine amongst surely mordant able functional groups acquaint inwards the natural dyes together with saltation past times coordinated/covalent bonds or hydrogen bonds together with other interactional forces. Thus, for proper fixation of natural dyes on whatever textile fibre, mordanting is essential inwards nearly of the cases.

Natural Dyeing

CLASSIFICATION OF NATURAL DYES
Natural dyes tin endure classified inwards a position out of ways. The earliest classification was according to alphabetical guild or according to the botanical names. Later, it was classified inwards diverse ways, e.g. on the reason of hue, chemic constitution, application shape etc.

• In “treatise on permanent colours” past times Bancroft, natural dyes are classified into 2 groups: ‘Substantive Dyes’ such every bit indigo, turmeric etc. which dye the fibres straight together with ‘Adjective Dyes’ such every bit logwood, madder etc. which are mordant amongst a metallic element salt. 

• Humme dissever the colouring thing every bit ‘Monogenetic Dyes’, those create exclusively 1 color irrespective of the mordant acquaint on the fibre or applied along amongst the dye together with ‘Polygenetic Dyes’, those create dissimilar color amongst dissimilar mordant applied, e.g., alizarin (Dedhia, 1998) 

• In the color index the natural dyes are classified according to the hue (Predominating colour).

ADVANTAGES OF NATURAL DYES

• The shades produced past times natural dyes/colorants are commonly soft, lustrous together with soothing to the human eye. 

• Natural dyestuff tin create a broad hit of colours past times mix together with jibe system. Influenza A virus subtype H5N1 little variation inwards the dyeing technique or the occupation of dissimilar mordant amongst the same dye (polygenetic type natural dye) tin shift the colours to a broad hit or practise totally novel colours, which are non easily possible amongst synthetic dyestuffs. 

• Natural dyestuffs create rare color ideas together with are automatically harmonizing. 

• Unlike non-renewable basic raw materials for synthetic dyes, the natural dyes are commonly renewable, beingness agro-renewable/vegetable based together with at the same fourth dimension biodegradable. 

• In only about cases similar hard a, indigo etc.,the waste matter inwards the procedure becomes an ideal fertilizer for occupation inwards agricultural fields. Therefore, no disposal job of this natural waste. 

• Many plants thrive on wastelands. Thus, wasteland utilization is an added merit of the natural dyes. Dyes similar madder grow every bit host inwards tea gardens. So at that spot is no additional terms or endeavor required to grow it. 

• This is a labour intensive industry, thereby providing project opportunities for all those engaged inwards cultivation, extraction together with application of these dyes on textile/food/leather etc. 

• Application of natural dyes has potential to earn carbon credit past times reducing consumption of fossil fuel (petroleum) based synthetic dyes. 

• Some of its constituents are anti-allergens, hence examine prophylactic for peel contact together with are generally non-hazardous to human health. 

• Some of the natural dyes are enhanced amongst age, piece synthetic dyes fade amongst time. 

• Natural dyes bleed but practise non stain other fabrics, turmeric beingness an exception. 

• Natural dyes are commonly moth proof together with tin supersede synthetic dyes inwards kid’s garments together with food-stuffs for safety. Despite these advantages, natural dyes practise deport only about inherent disadvantages, which are responsible for the turn down of this ancient fine art of dyeing textiles.

LIMITATION/ DISADVANTAGES OF NATURAL DYES

• It is hard to reproduce shades past times using natural dyes/colorants, every bit these agro products vary from 1 crop flavor to only about other crop season, house to house together with species to species, maturity menstruum etc. 

• It is hard to standardize a recipe for the occupation of natural dyes, every bit the natural dyeing procedure together with its color evolution depends non exclusively on color constituent but likewise on Materials. 

• Natural dyeing requires skilled workmanship together with is hence expensive. Low color yield of root natural dyes thus necessitates the occupation of to a greater extent than dyestuffs, larger dyeing fourth dimension together with excess terms for mordant together with mordanting. 

• Scientific backup of a large component of the scientific discipline involved inwards natural dyeing is notwithstanding demand to endure explored. 

• Lack of availability of precise technical cognition on extraction together with dyeing techniques. 

• The dyed textile may modify color when exposed to the sun, effort together with air. 

• Nearly all-natural dyes amongst a few exceptions require the occupation of mordant to ready them on to the textile substrate. While dyeing, a substantial share of the mordant remains unexhausted inwards the residuum dye bathroom together with may pose serious effluent disposal problem. 

• With a few exceptions, nearly of the natural dyes are fugitive fifty-fifty when applied inwards conjunction amongst a mordant. Therefore, sometimes their color fastness functioning ratings are inadequate for modern textile usage. 

 

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