Tuesday, December 18, 2007

MERITS AND DEMERITS OF NATURAL DYES

ADVANTAGES OF NATURAL DYES: -

1) Health and safety aspects of natural dyes: Though all natural dyes are not 100% safe they are less toxic than their synthetic counterparts. Many of the natural dyes like turmeric, annatto and saffron are permitted as food additives. Many natural dyes have pharmacological effects and possible health benefits.
2) They are obtained from renewable sources.
3) Natural dyes cause no disposal problems, as they are biodegradable.
4) Practically no or mild reactions are involved in their preparation.
5) They are unsophisticated and harmonized with nature.
6) Many natural dyes have the advantage that even though they have poor wash fastness ratings, they do not stain the adjacent fabrics in the washing process because of the non-substantive nature of the dye towards the fabric. An exception to this is turmeric, which shows substantivity for cotton.
7) Natural dyes are cost effective
8) It is possible to obtain a full range of colours using various mordants.

LIMITATIONS OF NATURAL DYES

The limitations of natural dyes that are responsible for their decline are: -

Ø Availability
Ø Colour yield
Ø Complexity of textile dyeing process
Ø Reproducibility of shade
Besides these there are other technical drawbacks of natural dyes: -
These are: -
Ø Limited number of suitable dyes
Ø Great difficulty in blending dyes
Ø Non-standardized
Ø Inadequate degree of fixation
Ø Inadequate fastness properties except few exceptions
Ø Water pollution by heavy metals and large amounts of organic substances.

6 comments:

Helen said...

Some natural dyes have a high wash fastness although I would agree with a statement that washfastness is generally considered to be poorer than for synthetic dyes as a group. However if you consider turkey red ( madder dyeing on cotton) as an example of natural dyes you would have to say that the fabric would disintegrate before the colour washed out it was so wash fast so it is difficult to make hard and fast statements about natural dyes in general only in specific.

n.s. said...

one major disadvantage which is ignored in case of natural dyes is that if we switch over to natural dyes in a major way , that will definitely affect the ever decreasing the green cover on this planet , because most of these dyes are obtained from trees and plants.At the same time the yield is very less as well as the color value is also very poor.

Anonymous said...

Whatever.
Natural dyes rock.

yashaswi said...

well said mr./ms. anonymous....
it rocks

Alchemist Nick said...

I would just want to know who is the author of this blog?

Anonymous said...

Yes natural dyes rock! I have seen a amazing online shop, luonnonhedelmat.com which sells certified organic fabrics and apparels dyed with natural herbal colors..