1. Water quality
1. Water requirements for dyeing and finishing:
Colorless, tasteless, odorless, clear (i.e. no turbidity), less salt (i.e. less various positive and negative ions) such as: calcium, magnesium, iron salts and chlorine.
1.1 Example:
a. Water containing iron salts will cause fabrics to turn yellow and cause rust spots, and cotton fibers will be brittle. change.
b. Water containing too much chloride will affect the whiteness of bleached fabrics.
c. Water containing calcium and magnesium ions can also form precipitation with dyes, resulting in poor dyeing brightness and reduced fastness.
1.2 Hard water: water containing calcium and magnesium ions.
1.3 Hardness: The content of calcium and magnesium ions or calcium and magnesium salts is expressed by “hardness”.
1.4 Alkalinity: Water may also contain alkaline substances such as sodium carbonate, which can form the “alkalinity” of water.
2. Methods for measuring water quality:
2.1 Suspended solids : Turbidity can be measured with turbidity juice
2.2 Alkalinity: PH value can be measured with acidity juice
2.3 Iron content: Chromium-cobalt mixed solution (K2Cr2O7+COSO4) with different concentrations can be used as a standard solution for colorimetric determination to determine the iron content.
2.4 Chlorine content: Titrate the water sample with silver nitrate standard solution.
2.5 Hardness: Calcium and magnesium content, one of the hardness expressions
PPm: It is defined as parts per million of water Containing one part of calcium carbonate is called 1 ppm hardness.
O-72PPm is very soft water
72-143PPm is soft water
143-215PPm is medium soft water
215-322PPm is very hard water
322-537PPm is hard water
More than 537PPm is very hard water. The hardness of knitting dyeing and finishing water must not be higher than 100PPm
2. Water treatment
1. The so-called water treatment quantity is to remove impurities contained in the water. deal with.
2. For turbid water, sedimentation → filtration → softening should be performed first.
Directly soften the clarified water, and water with high water quality requirements → softening. Treatment→Exhaust→Alkali→Deacidification→Desalination</p
