NATURAL DYEING OF COTTON FABRIC USING TERMINALIA CHEBULA (KADUKKAI) AND TURMERIC (CURCUMA LONGA) PART-1
Textile Chemistry, SSM College of Engineering,
Komarapalayam, Namakkal, India.
Textile Chemistry, SSM College of Engineering,
Komarapalayam, Namakkal, India.
An innovative approach was made to utilize the eco-friendly dyeing using renewable sources such as KADUKKAI and TURMERIC to produce herbal medicated textile material which are free from chemicals, detergent and pollution. In this project eco-friendly Garments, inner wears, Child clothing’s& home Furnishing materials were developed by dyeing cotton fabric with herbs like TERMINALIA CHEBULA (KADUKKAI) and TURMERIC (CURCUMA LONGA). These herbs are extensively used to heal chromic fever, skin and eye diseases, allergies, Asthma, rheumatic, body ache, diabetes, skin infections and allergies. In contact with clothing, the skin absorbs the medicinal qualities of the herbs. Compared to the synthetic dyed cotton fabric, the above dyed fabrics showed excellent results in terms of fastness properties. Herbal Textile is finished entirely with herbal extractions, without using any chemicals. These herbs are applied directly to the fabric with the help of natural ingredients, so that the medicinal value of the herbs can be kept intact. No chemical process is adopted while finishing process. Herbal treated cloth has the ability to protect us from various skin diseases, provides relief from viral infected disease and mental depressions since the herbal finished clothes or garments come in prolonged contact with the human body. The medical properties of herbs are known to cause no damage to the human body.
Keywords: Dyeing, Cotton Fabric, Terminalia Chebula, Turmeric, Fastness.
Textile materials (Natural or Synthetic) used to be colour for value addition, look and desire of the customers. Anciently, this purpose of colouring textile was initiated using colours of natural source, until synthetic colours/dyes were invented and commercialized. For ready availability of pure synthetic dyes of different types/classes and its cost advantages, most of textile dyers/ manufacturers shifted towards use of synthetic colorant. Almost all the synthetic colorants being synthesized from petrochemical sources through hazardous chemical processes pose threat towards its eco-friendliness. Hence, worldwide, growing consciousness about organic value of eco-friendly products has generated renewed interest of consumers towards use of textiles (preferably natural fibre product) dyed with eco-friendly natural dyes. Natural dyes are known for their use in colouring of food substrate, leather as well as natural fibres like wool, silk and cotton as major areas of application since pre-historic times. Although this ancient art of dyeing textiles with natural dyes withstood the ravages of time, but due to the wide availability of synthetic dyes at an economical price, a rapid decline in natural dyeing continued. Thus, natural dyeing of different textiles and leathers has been continued mainly in the decentralized sector for specialty products along with the use of synthetic dyes in the large scale sector for general textiles/apparels owing to the specific advantages and limitations of both natural dyes and synthetic dyes. The use of non-allergic, non-toxic and ecofriendly natural dyes on textiles has become a matter of significant importance due to the increased environmental awareness in order to avoid some hazardous synthetic dyes. However, worldwide the use of natural dyes for the coloration of textiles has mainly been confined to artisan / craftsman,small scale/cottage level dyers and printers as well as to small scale exporters and producers dealing with high-valued ecofriendly textile production and sales. Recently, a number of commercial dyers and small textile export houses have started looking at the possibilities of using natural dyes for regular basis dyeing and printing of textiles to overcome environmental pollution caused by the synthetic dyes. Natural dyes produce very uncommon, soothing and soft shades as compared to synthetic dyes. On the other hand, synthetic dyes are widely available at an economical price and produce a wide variety of colors; these dyes however produce skin allergy, toxic wastes and other harmfulness to human body.
GENERAL REVIEW ON SYNTHETIC DYESA dye can generally be described as a colour substance that has an affinity to the substrate to which it is being applied and is used to impart colour to materials of which it becomes an integral part. Dyes are widely used in industries such as textiles, rubber, plastics, printing, leather, cosmetics, etc.to colour their products. As a result, they generate a considerable amount of coloured wastewater. There are more than 10,000 commercially available dyes with over 7 x 105 tons of dyestuff produced annually. It is estimated that 2 % of dyes produced annually is discharged in effluents from associated industries. Among various industries, textile industry ranks first in usage of dyes for coloration of fibre. The total dye consumption of the textile industry worldwide is in excess of 107 kg/year and an estimated 90 % of this ends up on fabrics. Consequently, 1,000 tones/year or more of dyes are discharged into waste streams by the textile industry worldwide (March 1996).Many types of dye are used in textile industries such as direct, reactive, acid and basic dyes, sulphur, metal complex dyes. The main source of waste water generated by the textile industry originates from the washing and bleaching of textile materials and, from the dyeing and finishing stages. Dyes exist in two forms one is True colour and the other is apparent colour. Apparent colour can be removed very easily where as True colour is very hard to treat. Since Organic content reduces the Dissolved Oxygen content in the water and becomes a threat to the Aquatic life and dyes used in textile industries are very carcinogenic, mutagenic and toxic in nature leads to the chronic effects towards human beings.
Numerous studies have been conducted to assess the harm impacts of colorants on the ecosystem. It was found that colorants may cause problems in water in several ways:
- Dyes can have acute and/or chronic effects on exposed organisms with this depending on the dye concentration and on the exposure time;
- Dyes are inherently highly visible, minor release of effluent may cause abnormal coloration of surface waters which captures the attention of both the public and the authorities.
- The ability of dyes to absorb/reflect sunlight entering the water, this has drastic effects on the growth of bacteria and upsets their biological activity;
- Dyes have many different and complicated molecular structures and therefore, are difficult to treat and interfere with municipal waste treatment operations.
- Dyes in wastewater undergo chemical and biological changes, consume dissolved oxygen from the stream and destroy aquatic life.
- Dyes have a tendency to sequester metal ions producing micro toxicity to fish and other organisms.
The low level of fixation can be a major problem when dyeing with synthetic dyes when less than 70% of the dye reacts with the fibre. This results in unfixed dye being discharged into the dye house effluent. This problem, coupled with high salt concentrations used when dyeing with synthetic dyes, causes a significant environmental problem.
POLLUTION PROBLEMS IN TEXTILE INDUSTRY
Presence of colour in the waste water is one of the main problems in textile industry. Colours are easily visible to human eyes even at very low concentration. Hence, colour from textile wastes carries significant aesthetic importance. Most of the dyes are stable and has no effect of light or oxidizing agents. They are also not easily degradable by the conventional treatment methods. Removal of dyes from the effluent is major problem in most of textile industries.
Dissolved solids contained in the industry effluents are also a critical parameter. Use of common salt and Glauber salt etc. in processes directly increase total dissolved solids (TDS) level in the effluent. TDS are difficult to be treated with conventional treatment systems. Disposal of high TDS bearing effluents can lead to increase in TDS of ground water and surface water. Dissolved solids in effluent may also be harmful to vegetation and restrict its use for agricultural purpose.
Waste water of textiles is not free from metal contents. There are mainly two sources of metals. Firstly, the metals may come as impurity with the chemicals used during processing such as caustic soda, sodium carbonate and salts. For instance, caustic soda may contain mercury if produced using mercury cell processes. Secondly, the source of metal could be dye stuffs like metalized mordant dyes. The metal complex dyes are mostly based on chromium.
The use of chlorine compounds in textile processing, residual chlorine is found in the waste stream. The waste water (if disposed without treatment) depletes dissolved oxygen in the receiving water body and as such aquatic life gets affected. Residual chlorine may also react with other compounds in the waste water stream to form toxic substances.
Textile effluents are often contaminated with non-biodegradable organics termed as refractory materials. Detergents are typical example of such materials. The presence of these chemicals results in high chemical oxygen demand (COD) value of the effluent. Organic pollutants, which originate from organic compounds of dye stuffs, acids, sizing materials, enzymes, tallow etc. are also found in textile effluent, such impurities are reflected in the analysis of bio-chemical oxygen demand (BOD) and COD. These pollutants are controlled by use of biological treatment processes. In many textile units, particularly engaged in synthetic processing, low BOD/COD ratio of effluent is observed which makes even biological treatment not a ready proposition. The waste water of cotton based textile unit is usually alkaline, whereas synthetic and woollen fabric processing generates acidic effluent.