RMUTP International Conference: Textiles & Fashion 2012 July 3-4, 2012, Bangkok Thailand 1 SECTION III ECO-FRIENDLY PRINTING OF COTTON FABRIC USING NATURAL DYE FROM ACACIA CATECHU WILLD. Charoon Klaichoi 1, a* , Rattanaphol Mongkholrattanasit 2, b , Chamlong Sarikanon 3, b Potjana Intajak 4, b , and Warunee Saleeyongpuay 5, b a Department of Textile Product Design, b Department of Textile Chemistry Technology, Faculty of Industrial Textiles and Fashion Design, Rajamangala University of Technology Phra Nakhon, 517, Nakhonsawan Road, Kwang Suan Chitladda, Dusit District, Bangkok, 10300, Thailand 1 jaroon.k@rmutp.ac.th 2 rattanaphol.m@rmutp.ac.th 3 chamlong.s@rmutp.ac.th Abstract: Cotton fabric samples were printed with acacia catechu wild using reactive-printing technique has been investigated. The effect of different factors, i.e. quantities of urea, thickening agent and Sodium bicarbonate has been studied. The printed goods were evaluated by measuring the K/S values and the overall fastness properties. The results show that the colour strength (K/S) value of recipe 3 was the best printed result, and the next good result was obtained in the order of recipe 2 and recipe 1. The colour fastness results were ranging between fair and good level. Keywords: Acacia catechu willd., Thickening, Printing, Textile, Cotton, Natural dyes 1. Introduction Natural dyes, dyestuff and dyeing are as old as textiles themselves. Man has always been interested in colours; the art of dyeing has a long past and many of the dyes go back into prehistory. It was practised during the Bronze Age in Europe [1]. Natural dyeing has been used by humans for purposes varying from coloration of food, cosmetics, and textiles to impart other functions to them [2]. Nowadays, a revival interest in the use of natural dyes in textile coloration has been growing. This is a result of the stringent environmental standards imposed by many countries in response to the toxic and allergic reactions associated with synthetic dyes [3]. Natural dyes have a wide range of shades that can be obtained from various parts of plants, including roots, bark, leaves, flowers and fruits [4]. Dyeing with natural dyes, however, normally requires the use of mordants, which are metallic salts of aluminum, iron, chromium, copper, among others, for ensuring a reasonable fastness of the colour to sunlight and washing [5]. The metal ions of these mordants can act as electron acceptors for electron donors to form coordination bonds with the dye molecules, making them insoluble in water. The use of natural dyes cuts down significantly on the amount of toxic effluent resulting from synthetic dye processes. Natural dyes have also been used for printing [6 - 8]. Acacia catechu Willd. (Family: Fabaceae and subfamily: Mimosoideae) is a moderately sized deciduous tree with rough, dark grayish brown bark. It is a native of Central and East Africa, Southern Asia, Bhutan, Thailand, China, India, Myanma, Nepal and Pakistan [9]. It grows up to 13 meters in height. The leaves are pinnate with a pair of recurved prickles at the base of the rachis. Flowers are pale yellow arranged in cylindrical spikes. Pods are glabrous oblong. The sapwood is sharply distinct from heartwood, light yellowish-white or yellow. Heartwood is deep red or reddish brown, darkening on exposure. The different parts of the tree have a variety of medicinal uses. In ayurveda, the bark and heartwood are used to treat various conditions like thinning of blood, tooth related troubles, skin disorders, chronic fever, worm infestation, throat problems, obesity, hepatomegaly and spleenomegaly, tastelessness, hemorrhages, blood disorder and urine related disorders [10]. The plant is used for fodder, fuel and katha paste [9]. Cutch is a very easy dye to work with. It shows excellent fastness on cotton