THE EFFICACY OF TRADITIONAL DYES: OSOGBO DYE AS A CASE STUDY

CHAPTER TWO

RELATED LITERATURE

        This literature review consists of many sub-sections beginning with the history of indigo dye the production of Indogo dye, traditional dyes and batik. The aim of this review is to give a concise background of indigo and its reduction methods.

2.1      HISTORY OF INDIGO DYE

Indigo dye has been used for thousands of years, and it is one of the oldest dyes used by mankind. There is evidence of indigo being used in mummy cloths in ancient Egypt. Before the synthetic dyes were developed in the 19^th century, Indigo as well as other dyes were produced from plants. In Europe, Dyer’s Woad was cultivated for Indigo production Japan Woad is a temperate herbacea biennial plant and it produces rose leaf on the first year which are harvested for the indigo production and in the second year it produces flower stems and seeds for reproduction. Woad is native to south-east Russia and it has spread from these  cultivation into the rest of Europe. Woad was an important crop in Europe in the middle ages and it brought immense wealth to the woad traders.

The renowned centers of the trade were Toulouse in France and Erfurt in Germany which still have some lingering effect of woad commerce. The tropical indigo overtook European markets in the 17^th century. Even though the woad traders did all in their power to stop the indigo produced in India, Java replaced woad in such a way that the woad cultivation was diminished until it disappeared entirely in the beginning of the 20^th century, with the appearance of synthetic indigo in the markets.

Synthetic dyes brought also other blue dyes and these had superior qualities when compared to indigo as well. Lately, there has been new demand on oil based dyes, and there are on-going researches on developing methods to produce biologically manufactured indigo.

2.2      PRODUCTION OF INDIGO

The structure of indigo was first suggested by Von Bayer in 1869 and the first commercially successful synthesis of indigo was based on the process published by Hermann in 1890. The BASF started the production in 1897. This synthesis process converted phenylglycine-o-carboxylic acid by fusion with sodium hydroxide into indigo via indoxy-1-2-carboxylic acid. Indigo production with hydrocarbon degrading bacteria expressing mono-oxygenases or dioxygenases has also been investigated in search of a possible alternative for the chemical synthesis of indigo. For example, Beny et al developed a fermentation process where indigo was produced from glucose with recombinant Escherichia coli which had been modified with pseudomonas putida genes.

However, the method produced also indivubin which gave undesirable red to the dyeing result which they were able to suppress to a point.

In the traditional method of producing indigo blue (also called Woad), from woad, the leaves were crushed to pulp which was kneaded into balls, and allowed to dry for several weeks. These dried balls could then be stored. The balls needed to be couched before they could be used in dyeing. The couching means crushing the balls into powder and wetting it, then allowing the material to ferment for several weeks again.

After couching the woad which was like dark-clay like material was dried and packed tightly before use. The dye from woad was very impure and it gave only light colours and this was the reason why the exotic indigo from the indigofera species could overtake woad so completely. The indigo from tropics was a better quality and it could be used to produce darker blues. However, even this was still impure and was substituted by the synthetic indigo which always produced purities over 90%.

The extraction from the indigo was done differently from the woad extraction. The plant material was steeped with water (fermentation), after the solution was oxidized with air. The modern extraction method of indigo from woad follows a similar method and the woad balls are no longer made.

        The modern extraction method of indigo from woad uses the water solubility of the indigo precursors in steeping the leaves in hot water. The precursors are broken down to indoxyl and sugar moieties by enzymes in plant, but in the extraction method, this is done by alkali with aeration.

        The purity of plant-derived indigo even with the modern extraction method is somewhat low when compared to the synthetic indigo. Natural indigo contains besides indigo, impurities such as indirubin, indigo gluten and mineral matter. The indigo purity has been reported to be for woad indigo 20-40%, for pinctorium up to 12% and for indigofera indigo the highest from 50 up to 77%.

        There is also the question of the efficiency of the extractions the theoretical yield approximately 60%. So 40% of the indoxyl is lost during the process to impurities such as isatin and indirub in and other by products of the reaction.

The colour of indigo is dependent on its environment. Indigo is classified as a vat dye although its properties are not typical to the vat dyes as a whole. Indigo has been mentioned to have a moderate to very high light-fastness, depending on the substrate it is on, or whether it is as a pigment or a dye. All in all, it is among the most photo-stable natural dyes.  Light  mostly affects the oxidative degradation of indigo.

Traditional Dyes

Traditional dyes are dyes or colorants derived from plants, Majority of these traditional dyes are vegetable dyes from plant sources like roots, berries, bark, leaves, and wood.

        Archeologists have found evidence of dyeing textiles as far back as the Neolithic period in China, Infact dyeing with plants, barks and insects has been traced back more than 5,000 years.

        Barber, (1991), states that the essential process of dyeing changed a little, over time. Typically, the dye material is put in a pot of water and then the textile to be dyed is added to the pot which is heated and stirred until the colour is transferred. Textile fiber may be dyed before spinning (dyed in the Woad) but most textiles are “yarn-dyed” or “piece dyed” after weaving.

Many traditional dyes require the use of chemicals called mordants to bind the dye to the textile fibers.

   Natural alum, vinegar and ammonia from stale urine were used by early dyes. Many mordants and some dyes themselves, produce strong odour and large-scale dye works were often isolated in their own districts. Throughout history, people have dyed their textiles using common locally available materials, but scarce dyestuffs that produce brilliant and permanent colours such as the traditional  dyes. across Asia and Africa, patterned fabrics were produced using resist dyeing techniques to control the absorption of colour in piece-dyed cloth which were brought to Europe by the Spanish and the dye stuffs of Europe were carried by colonists to America.

        According to Cannon John and Cannon Margaret (2002), the discovery of man-made synthetic dyes in the mid-19^th century, triggered off a long decline in the large-scale market for traditional dyes. Synthetic dyes, which could be produced in larger quantities, quickly superseded traditional dyes for commercial textile production, enabled by the industrial revolution

    Traditional dyes  mellow with age but preserve their true colours unlike early synthetic dyes this helped to ensure that the old European techniques for dyeing and printing with natural dye stuffs were preserved for use by home and craft dyers. Traditional dyeing techniques are also preserved by artisans in traditional cultures around the world.

According to Barber (1991), in the early 21^st century, the market for traditional dyes in the fashion industry  experienced a resurgence. Western consumers  became more concerned about the health and environmental impact of synthetic dyes in manufacturing and there was a growing demand for products that used traditional dyes. The European union, for example,  encouraged Indonesian batik cloth producers, to switch to traditional dyes to improve their export market in Europe.

Processes of Traditional dyes

According to Goodwin Jill (1982), the essential process of dyeing requires soaking the material containing the dye (i.e the dyestuff) in water, adding the textile to be dyed to the resulting solution (the dye bath) and bringing the solution to a simmer for an extended period, which is offer measured in days or even weeks, stirring occasionally until the colour has eventually transferred to the textile fabric.

Some dye stuffs, such as indigo and lichens, will give good colour when used alone; These dyes are called direct dyes or substantive dyes. Majority of plant dyes however also require the use of a mordant  chemical used to “fix” the colour on the fabric. These dyes are called adjective dyes. By using different mordant, dyers can often obtain a variety of colours and shades from the same dye fiber

In traditional dyes the common mordant are vinegar, tam inform of oak bark sumac or oak galls, ammonia from stale urine and wood ash liquor or potash (potassium carbonate] made by leaching wood ashes and evaporating the solution. One can never know by what chances primitive man discovered that salt, vinegar from fermenting fruit, natural alum, and stale urine, helped to fix and enhance the colours of his yarns, but for many centuries these four substances were used as mordants.    

        Salt helps to fix or increase fastness of colours, vinegar improves reds and purples, while ammonia in stale urine, assists in the fermentation of indigo dyes. Natural alum (aluminum sulphate) is the most common metallic salt mordant, but tin (stannous chloride) copper (cupric sulfate) iron ferrous sulfate called copperas) and chrome (potassium dichromate) are also used. Iron mordants “sadden” colours, while tin and chrome mordants brighten colours. The iron mordant contribute to fabric deterioration, referred to as “dye rot”. Additional chemical or alterants may be applied after dyeing to further alter or reinforce the colours.

Barber (1991) states that textiles may be dyed as raw fiber (dyed in the fleece or dyed in the Woad), as spun yarn (dyed in the hank or yarn dyed) or after weaving (plecedyed). Mordant often leave residue in Wool fiber that makes it difficult to spin, so Wool was generally dyed after spinning as yarn or woven cloth.

Indigo, however, requires no mordant. Cloth manufacturers in medieval England  dyed Woad in the fluce with the indigo-bearing plant [Woad] and then dyed the cloth again after weaving, to produce deep blues, browns, reds, purples and blacks  In China, Japan, India, Pakistan, Nigeria, Gambia, and other parts of West Africa and South East, Asia, patterned silk and cotton fabrics were produced using resist dyeing techniques in which the cloth is printed or sterilized with starch or wax, or tied in various ways to prevent even penetration of the dye when the cloth is piece-dyed. Chinese Ladao is dated to the 10^th century: other traditional techniques include tie-dye, batik, to mention but a few.

        The mordant used in dyeing and many dye stuffs themselves, give off strong and unpleasant odour. The actual process of dyeing requires a good supply of fresh water, storage areas for bulky plant materials, vats which can be kept heated (often for days or weeks) and airy spaces to dry the dyed textiles. Ancient large-scale dye-works tended to be located on the outskirts of populated areas, which are often windy.

WHAT IS BATIK ­

        This is a method of dyeing fabric by which the part of the fabric not intended to be dyed are covered with removable wax.

HISTORY OF BATIK

        Evidence of early examples of batik have been found in the far Middle East, Central Asia and India for over 2000 years  It is conceivable that those areas developed independently without the influence of trade or cultural exchanges. However, it is more likely that the craft spread from Asia to the Island of the Malay Archipelago and west to the Middle East through the Caravan route.

Batik was practiced in China as early as the sul Dynasty (AD 581-618). There were silk batik and these have also been discovered in Nara, Japan in the form of screens and ascribed to the Nara period (AD 719-794). It is probable that those were made by Chinese artists.  They were discovered with trees, animals, flute players, hunting scenes and stylized mountains.

        No evidence of very old cotton batik have been found in India but frescoes in the Ajunta caves depict head wraps and garments which could well have batiks. The java and Bali temple ruins contain figures whose garments are patterned in a manner suggestive of batik. By 1672, there was evidence of a considerable export trade, mostly on silk from China to Java, Sumatra, Persia and Hindustan in Egypt. Linen and occasionally wollen fabrics have been excavated bearing white patterns on a blue ground. They are the oldest known and they date as far back as the 8th century A.D. They were made in Egypt, possibly Syria in Central Africa. Resist dyeing using cassava and rice paste have existed for centuries in the Yoruba tribe of southern Nigeria and Senegal.

Indonesia, most particularly the Island of Java is the area where batik has reached the greatest peak of accomplishment. The Dutch brought Indonesian craftsmen to teach the craft to Dutch warders in several factories in Holland in 1835. The Swiss produced imitation batik in the early 1940s. A wax block form of printing was developed in java using a cap. By the early 1900s the Germans had developed mass production of batiks. There are many examples of this form of batik as well as hand-produced batik in many parts of the world today computerization of batik techniques is a very recent development. But the techniques the researchers is using, is the traditional dye resist technique on fabrics using Africa motifs.

Materials Used in Making Batik

i.            The fabric (cloth material)

ii.          Scissors:

This is used for cutting fabrics into different hence and sizes of your choice.

iii.       Table:

The table plays the most important role when it comes to making batik. This is because one can easily spread the fabric to be waxed on the table.

iv.        Candle wax

The wax is the major tool because it what is used to inscribe design on the fabric.    

v. Stove:

        Stove is used for boiling the wax before using it to inscribe the design

Vi. Pot:

        Pot is used for boiling the wax.

vii. Tape:

        It is use for measuring   the fabric.

viii. Foam:

Foam is often used when you design and the foam must be carved in such a way that it has a pointed tip.

ix.        Caustic soda:

This is one of the chemicals used for dyeing the fabric.  It enables the dye substance perpetrate the fabric fast. It can also be used to bleach the fabric, if need be.

x.          Hydrosulphite:

This is another chemical that is used to make the dye remain permanent on the fabric.

xi.        Bowls:

The bowl is mainly used to dye the waxed fabric.

xii.      Rubber gloves:

They are for protecting the hands from the dye when dipping the fabric in the dye stuff.

xiii.   Dyeing pot:

This is used for de waxing the dyed fabric.

xiv.    Sewing machine:

This is used to sew the dyed fabric into end-use.

ABSTRACT:          CHAPTER ONE:          CHAPTER TWO:

CHAPTER THREE:          CHAPTER FOUR:          CHAPTER FIVE:          REFERENCES:

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