Water Quality

Bureau Veritas CPS Division, India

C

otton is the backbone of World’s Textile Trade. It has countless end

uses after various processes or treatments. So many steps are involved to get the desired end use. The wet treatment survives several types of problems resulting defects and faults. Quite frequently the problems in dyed/printed cotton material are not due to dyeing or printing process but due to some latent defects introduced by improper or impure water quality in processing stage. The use of water in textile wet processing is ubiquitous. Textile Wet Processing includes number of stages from Scouring/Bleaching to Finished Dyed or Printed fabric or Finished Garment. The raw material used in the largest quantity in almost every stage is water. Also this is main prerequisite in washing/laundering of garments or home furnishing products. Hence it is very important to do use proper water. Water from almost all sources contains various types of impurities. Calcium & Magnesium (hardness) Heavy Metals (Iron, Copper, manganese etc.) Aluminum Chlorine Miscellaneous Anions (Sulphide, Fluoride etc.) Sediments, Clay, Suspended Matter Acid, Alkali & Buffer Oil & Grease Dissolved Solids Colorless odorless water is called as Universal solvent as it easily picks up the impurities. The water contaminants/ impurities adversely affect the quality of wet processing stage as well as laundry of garments/ cotton product.

There are so many

to impure the water quality.

Water Storage Piping, Valves etc. Machinery Prior process in case of reuse. of impurities present in the water (used in Textile) The are summarized as under

Calcium and Magnesium are the primary mineral metals which are easily picked up by water resulting Hardness. More the concentration of these metals, more is the hardness of water.

The classification of water hardness by US Department of Interior and The Water Quality Association is stated as under.

The hard metals affect the surfactant at the time of laundry. The soap combines with the metals to form sticky soap curd. This card is deposited on the substrate that may prevent removal of soil and to some extent microorganism. The microorganism may cause odor problem by developing harmful bacteria. Moreover the deposit may result harsh hand feeling and stiffness is increased.

Using adequate amount of appropriate detergent and water as hot as recommended depending on the fabric & structure of the material. Using packaged water softener or water conditioner. Using sequestering agent viz. Ethelene Diamine Tetra Acetic Acid (EDTA) at wet processing stage.

The metal ions (Copper, Iron etc.) catalyzes the decomposition of Hydrogen Peroxide while using in bleaching. This results improper bleaching effect and high loss of tensile strength. Above all, laundry problem caused by high concentration of Iron content include yellow, orange or brown stain or spots or overall discoloration. Iron eventually decelerates the rate of bleaching that results undesired dull shade after dyeing.

Inconsistent shade, blotchy dyeing can be caused by the presence of chlorine contamination in water. Even at neutral pH the water may contain substantial amount of acid or alkali. It may retard the dye fixation; reduce the dye uptake exhaustion rate.

Sediments, Clay, Alum or other residuals from organic contamination are responsible for blotches and inconsistent shade due to uneven washing-off of unfix dye.

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The considerable amount of sulphide or fluoride ions can acidify the water resulting damage of physical properties of the cotton. In order to get rid off such problems, # in Textile Industry should meet fairly stringent demands to succeed our dream to get the fault free cotton product.

Pradip Bhattacharya B.Tech (Textile), PGD in Retail Management [email protected]