The discovery methods of synthesizing alizanin and indigo spelt the death knell of the indigenous industry. Due to the ease of application, bright shades obtained and the hard shell of the colonial rulers, hand weavers started to opt for synthetic dyes without a clear understanding of the using of these. It is now suspected that many of the synthetic dyes are carcinogenic in nature and havoc in life systems. It's ironic that Europe that initiated the advent of synthetic dyes in the first place woke up the dangers of these agents and turning down for a few members of this class, proven to be harmful to life forms.
Flowers are available in Eastern India & are grown almost every season but a huge amount of unsold flowers are wasted everyday in West Bengal. It can be used in small scale Industry as well as in large scale Industry. These unsold flowers create a big problem for disposal as well as these can create environment pollution also. But these unsold flowers can be used for dyeing purpose for Textile & residuals can be used as bio-fertilizers also. These flower dyes are eco-friendly also and it has no side effect on skin. An attempt has been made in laboratory scale and in pilot plant also using some selected flowers like Mari-gold for dyeing of textile fibre to get a clear idea of preparation of dye from these flowers & using it in Textile Industry and making the process economically viable.
Keywords: Floral dye; Textile fibre; synthetic dye; Marigold Flower
Dyeing of textiles mean giving them a colour, which is of comparative permanence. It implies that it should not be possible to wash the colour out easily in laundering, nor should it fade rapidly when exposed to light. In Textile Coloration Industry, effluents of dyes & associated chemicals are source of water pollution. So, due to the harmful effect of chemical dye on environment pollution, a number of countries have issued stricter regulations so as to preserve our environment. Not only that, these synthetic dyes may create allergic reaction on skin also. For this reason, now the interest of natural dyestuffs has revived in Europe, Japan and United states. Indian Government has also banned some use of Azo group which has harmful effect on environment.
In India especially in West Bengal, a huge amount of flowers are wasted everyday. A survey report reveals that among India, West Bengal is in 4th position to cultivate flowers after Andhra Pradesh, Karnataka & Tamilnadu. 40% of the total product flowers are wasted everyday. These flowers are thrown in water of Ganga river or any other places which creates water pollution.
But these flowers can be used to extract dye which can be used as natural floral dye for colouring textile fibre. These natural dye are cost effective, eco-friendly & renewable and has no allergic action on skin. For our work we have taken cotton fabric and we choose Marigold flowers, China rose flowers for dyeing the fibre.
Chemistry & Characteristics of Cotton Fibre:
Cotton is one of the most commonly abundant natural fibre & it is advantageous textile as it is more available, comfort, excellent heat conductivity & hygroscopic in nature. It is natural fibre chemically known as cellulose. Pure cellulose is a white substance with specific gravity of 1.5. Cold water causes cotton to swell but has no chemical action on it. Many of the natural dye has not only carboxy group, but also have aromatic hydroxyl group to function as water soluble groups. These are hydrolyzed in water to anions & because the surface of cotton is also anionic in water, repulsive forces act between dyes & fibre surface & consequently dyes can’t be easily absorbed. So, for this reason cotton fabric is to be treated i.e. to be cationized so that ionic attraction between dye-anions & fibre cations can be occurred easily. It increases the capacity of dye ability.