Colouration of Silk with Natural Dyes
Dr. Rajashree Phukon, Registration ID- AB/565 , Assist. Prof., Sibsagar Girls’ College, P.O.Sivasagar, Assam, Pin-785640, e-mail ID:firstname.lastname@example.org
Mr Diganta Kr. Borah, Research Scholar, Department of Economics, Dibrugarh University, Assam, India, e-mail ID: email@example.com.
The study was undertaken with an aim to develop the dyeing conditions of four different natural dyes which are easily available in North East India, namely Myrica nagi Thumb. (Bay berry), Garcinia xanthochymus Hook. f. (Cochin goroka), Artocarpus integrifolia Linn. f. (Jack fruit), and Eugenia jambolana Lam. (Black plum) on silk yarn. The natural mordant used in the research work is Aluminium Potassium Sulphate (AlK (SO4)2) for better fixation of the dyes. The dyes are extracted by alkaline method and the extraction time is optimized from the optical density values. The pre-mordanting method is used for mordanting the yarn. Shades of different colours, ranging from yellow to brown are obtained from the dyes on silk yarn. Fastness grades rated for all the samples are found to be good irrespective of all the dyes. The dyes are found to be an ideal source which could be adopted at commercial level.
Natural dyes have been part of man’s life, since time immemorial. The age-old art of dyeing with natural dyes was common in India. Natural dyes are obtained from natural sources such as vegetable matter, minerals and insects. Early efforts of colouring fabrics were hampered by the fact that some of the dyes are not very colourfast. Eventually scientist found that this defect could be partially overcome by the use of mordant. The natural colouring substances are now developing trends for their use all over the world because of health hazards and toxicity problems created by the synthetic dyes .
Considering the growing importance of natural colorants all over the world, the present work was undertaken with an aim to study the dyeing conditions of selected natural dyes on silk yarn.
3. Materials and methods:
3.1 Selection and Preparation of yarn for dyeing
Mulberry silk yarn was selected for dyeing and collected from a private firm near Guwahati, India. The natural gum sericin present in the silk hinders the dyeing process and hence silk needs to be degummed. Degumming of silk was carried out by using standard method .
3.2 Selection of natural dyes:
Table 1. Dye yielding plants selected for the study are:
|Sl. No. |Botanical name |Common name |Family |Parts used | |1 |Myrica nagi Thumb | Bay berry |Myriaceae |Bark | |2 |Garcinia xanthochymus Hook. f. |Cochin goroka |Guttiferae |Bark | |3 |Artocarpus integrifolia Linn. f. |Jack fruit |Moraceae |Root | |4 |Eugenia jambolana Lam. |Black plum |Myriaceae |Bark |
3.3. Selection of mordant: Mordant form the link between dyestuff and fibre, which allows the dye with no affinity for the fibre to be fixed . Among the mordant used for fixing natural dyes, metallic mordents are most common. The mordant used in the research work is Aluminium potassium sulphate (alum) AlK2 (SO4)2 which is consider as eco friendly .
3.4. Selection of mordant concentration
The amount of mordents used in dyeing plays an important role as the mordents forms the link between the dyestuff and fibre. After much preliminary work, the mordant concentration was determined which was mainly based on the percentage of absorption of the dye and visual assessment of the shade. Three mordant percentages...