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Soap making

The entire soap-making process is usually divided into two types:

• Chemical stage — direct soap making.
• Mechanical stage — additional processes take place in it, such as drying, introduction of fragrances and so on.

Chemical stage:

First, a mixture of various fatty acids is prepared (in some technologies resin and/or naphthenic acids are used instead) together with sodium salts or, less commonly, potassium salts.

Then the unrefined fats are treated with alkali. After this treatment, what is called “soap glue” is obtained.

Next, the resulting product is purified by various methods — it all depends on the source raw material.

In the final processes, the “glue soap” is treated with an excess of caustic soda or a solution of sodium chloride (table salt). After this treatment, the resulting soap substance separates into layers. A concentrated soap solution with a fatty acid concentration of up to 60% forms the upper layer. And in the lower layer remains the “spent lye”, which contains water, primary glycerol and by-product (contaminating) compounds of the source components.

After this stage, laundry soap is obtained, which also has the technical name “core soap”. Glycerol is also obtained at this same stage.

In some technologies, purified glycerol may be added to the soap at the mechanical stage.

Mechanical stage:

Cooling, drying, introduction of the necessary additives, packaging and other operations take place, depending on the requirements for the final product.

The resulting soap substance is crushed — it is passed through a milling unit, which consists of rollers for grinding.

The required shape is given to the final product during the pressing process.

When making toilet soap, the water concentration in the initial mixture is reduced to 12% and perfume additives, dyes and other components are introduced.

Quality improvement:

Coconut and/or palm oils are introduced into very good grades.

To improve certain properties of the final product, regardless of the grade, soda ash, borax, sodium tripolyphosphate, and liquid glass are added.

Saponin is added when making expensive grades.

In industrial production, fragrances, various preservatives and dyes, as well as other special additives, are introduced into a large number of soap grades. Please note that some of these additives can be harmful to human health.

To obtain a paste-like consistency, finely ground sand, various fatty clays, or finely crushed brick are added to the still-liquid laundry soap.

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