Caustic Soda Flakes

Caustic soda is mainly used in textile in the form of caustic soda flakes or pearls. It is also known as sodium hydroxide, has a white solid appearance and a formula of NaOH. It is an inorganic alkali salt, hygroscopic in nature and is soluble in water and polar solvents. It has a slippery feel and also absorbs carbon dioxide in the atmosphere to from sodium carbonate.



Being a base, it will undergo neutralization reaction with acid and form relevant salt and water. It will also corrode metals such as aluminum, generating hydrogen gas that has potential to behave as an explosive gas. Caustic soda also has decomposing effects on proteins and may penetrate deep tissues.



Manufacturing Process



Metathesis Reaction

By reacting sodium carbonate with calcium hydroxide, the reaction yields sodium hydroxide and calcium carbonate. Since sodium hydroxide is soluble while calcium carbonate is not, by doing filtration, calcium carbonate can be easily removed to obtain a crude solution of sodium hydroxide. This solution is then purified, processed and standardized for industrial consumption.



Chloralkali Process

With the electrolysis of sodium chloride solution, solid sodium hydroxide is manufactured and obtained with the evaporation of water. Chlorine gas is also produced as a main by-product. Electrolysis occurs through three main types of cells, mainly mercury cell, diaphragm cell and membrane cell.


Textile Industry

Caustic soda is applied in the manufacturing of textile. It is used in the scouring process and mercerization process. During the process of scouring, it aids in the removal of natural oil, wax and fat. During the process of mercerization, it aids in improving the tensile strength, smoothness and dye substantively of the cellulosic.