use of Sodium hydroxide in dyeing
Sodium hydroxide (NaOH), also known as lye and caustic soda is an inorganic compound. It is a white solid and highly caustic metallic base and alkali salt, which is available in pellets, flakes, granules, and as prepared solutions at a number of different concentrations. It used in many industries, including Caustic Soda in dyeing industries.
Dyeing or embroidery is referred to as a process where textile products such as fibers, yarns, fabrics or garments are stained in a solution containing dyes and chemicals, and color molecules with a durability relative to textile molecules have a strong bond They establish.
In other words, dyeing is a skill in which the dye material penetrates and paints it at a controlled temperature and at a specified time, inside the fibers or non-woven goods.
Dyeing has two, traditional and industrial ways. It should be noted that today, with the advancement of technology, the industrial method is commonplace and easier.
Materials used in dyeing (industrial and traditional):
- ۱-Alkaline materials such as Soda Ash / Caustic soda flakes / Sodium Caustic, known as Sodium Hydroxide, Ammonia and others.
- ۲-Types of acids and water that have certain properties.
- ۳- And also the color of the seeds, which is the most important substance.
These materials play a key role in coloring the fibers and keeping the color of the fibers intact.
Natural dyes have natural roots and can classified into three groups according to their extraction source:
Dyestuffs obtained from plants such as Nile, Rhinos, etc. from roots, flowers, leaves, fruits of the plant’s skin.
Dyestuffs derived from animals such as quartz and curly cloves.
In addition, those made of minerals like red soil.
How Caustic soda / Soda ash or Sodium hydroxide works in dyeing?
here is what is the use of Sodium hydroxide in dyeing.
Fibers exposed many external factors before they prepare for the dyeing process. Which causes the fibers to infect.
In addition, some fibers, such as wool, contain fat that comes from the body of the animal, these contaminants and fats, if not cleansed, prevent the penetration of color into the fibers.
In this step, before dyeing (washing), Caustic soda or Sodium hydroxide has the most important application.
Caustic soda is in shape of flake or powder that forms an alkaline solution by dissolving in water.
Due to its beneficial effect on degreasing, it is used in many industries as an industrial cleaner, or as industrial soap.
In the dyeing industry, it is used for the synthesis of fibers and the cleansing of fats before dying.
Other use of Sodium hydroxide
Another most popular use in dyeing is that, it is used with Hydrosulfite to make up with nylon and some other colors.
A very strong alkaline solution of very high concentration (caustic soda at 37-40%) at ambient temperature does not show a severe degradation effect on the wool, but only removes wool scales. Approximately (40) years ago used for scaling.
The 5% of caustic soda solution dissolves at the boiling point of the wool fiber for a maximum of 5 minutes, because at high temperatures the fiber pores open and the fibrous materials more easily damage the fibers
At a low temperature, this Destruction is less. After performing any alkaline operation, neutralization with acidic solution is necessary, since the remaining alkali has infiltrated the fibers of the fiber for a long time and causes damage to the wool.
Due to the use of alkali, the wool is rough, because its fats will be alkaline hydrolyzed. To compensate this, the cationic ingredients add to the wool.