Water Analysis -1
Bleaching is an operation to remove the coloured impurities from textile fibers. Cotton in its natural form contains so many minerals, waxes, proteins and colouring matters, etc. In order to attain a bright substrate for dyeing, bleaching or printing and to make the fabric uniformly water absorbant, a pretreatment is essential. So the first and foremost textile processing operation is called pretreatment, that remove remove the unwanted matters, such as color, minerals, waxes and oils and stains from the greige material. The pretreament operation untilizes a lot of water and the quality of water plays a vital role in the cleansing of textile materials. Better the quality of water, better will be the processed goods.
As water and its quality play a very important role in wet processing, let us have a brief look into the quality of water required for wet processing, with an emphasis on reactive dyeing. We get water from various sources, like river, ponds, shallow wells and deep bore wells. According to the source of water, it contains many dissolved and suspended impurities. The water from a running river, contains many dissolved salts (solids) like Sulphates, Chlorides, silicates, Carbonates and Bicarbonates of heavy earth metals like Calcium, Magnesium, Iron, Aluminums, Sodium etc. The ratio of these salts varies according to the source of water.