Physical and Chemical Properties of Water Used in Textile Wet Processing
Mohebul Hasan
Dept. of Textile Engineering
Green University of Bangladesh
Email: sajrul96@gmail.com
Water in Textile Wet Processing:
The textile industry consumes large amount of water in its varied processing operations. In the mechanical processes of spinning and weaving, water consumed is very small as compared to textile wet processing operations, where water is used extensively. Almost all dyes, specialty chemicals and finishing chemicals are applied to textile substrates from water baths. In addition, most fabric preparation steps, including desizing, scouring, bleaching, and mercerising use aqueous systems. In textile wet processing, water is used mainly for two purposes. Firstly, as a solvent for processing chemicals and secondly, as a washing and rinsing medium.
In wet processing, water consumption is used greater than the amounts of fibers processed. It is the ubiquitous solvent for the solutions of chemicals used. For this we should know details about water. Physical and chemical properties of water used in textile wet processing industry are given below:
General / Physical Properties of Water Used in Textile Industry:
- Water when pure has no color no taste and no orider.
- The plaseut teste of water is due to dissolued gases and salts present in the water.
- Melting point 0ºC.
- Boiling point at 760mm hyprressure-100ºC.
- Heat of fusion 79.7 cal/g
- Heat of uaporisction 539.6 cal/g
- It shows highest density at 40ºC -18m/ml
Chemical Properties of Water / H2O:
1. Water has a gnat thermal stability and not closely decomposed into elements,
2H2O + 69000 cal = 2H2O + O2
2. Water is poor conductor of electricity.
3. Electropositive metal react with water violently and liberate hydrogen
2Na + H2O =2NaOH + H2
4. Electronegative metal react with water at ordinary temperature
Cl2 + H2O = HCl+HClO
5. Most organic compound are insoluble in water but non-polar organic compound like ether, bengene, alcohol, are soluble in water.
Standard / Ideal Quality of Dye House Water:
| Minimum Standard | Permissible Concentration |
| Color | Color less |
| Smell | Odour less |
| PH | Neutral (7-7.5) |
| Water hardness | <56dh/<25ppm25mg/l |
| Solid deposit | <50mg/l |
| Inorganic salts | <500mg/l |
| Fe | <0.1mg/l |
| Cu | <0.005mg/l |
| Nitratc | <50mg/l |
| Nitritc | <5mg/l |
| Manganese (Mn) | <0.02mg/l |
| Silicone (Si) | <3mg/l |
| Total dissolve solid (TDS) | 65-150mg/l |
| Alkalinityat pH 4 | 35-65 crcog |
You may also like:
- Water Management in Textile Industry – An Overview
- Water Consumption in Textile Processing Industry
- Waterless Dyeing Technology in Textile Processing
- Potential Problems Caused by Hard Water in Textile Wet Processing Industry
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
