Soap is widely used, in addition to the familiar ones for washing clothes, and is widely used in the textile industry. Usually used as the sodium salt of higher fatty acids, generally called hard soap; its potassium salt is called soft soap, mostly used for shampooing and shaving. Its ammonium salt is often used as a cream. According to the composition of the soap, from the fatty acid part, the soap made by the saturated fatty acid is relatively hard; on the contrary, the soap made by the unsaturated fatty acid is relatively soft. The main raw material for soap is a fat with a higher melting point. Considering the length of the carbon chain, in general, the carbon chain of the fatty acid is too short, and the soap made is too soluble in water; if the carbon chain is too long, the solubility is too small. Therefore, only the potassium salt or sodium salt of C10-C20 fatty acid is suitable for soap. In fact, the sodium salt of C16-C18 fatty acid in soap is the most.
Soap usually contains a lot of water. After adding spices, dyes and other fillers to the finished product, a variety of soaps are obtained.
The commonly used yellow laundry soap is generally blended with rosin, which is added in the form of a sodium salt for the purpose of increasing the solubility of the soap and foaming, and is also relatively inexpensive as a filler.
White laundry soap is added with sodium carbonate and water glass (up to 12%), and the general laundry soap contains about 30% water. If the white laundry soap is dried and cut into thin slices, a soap tablet is obtained for washing the high-grade fabric.
A suitable amount of a mixture of phenol and cresol (preservative, bactericidal) or boric acid is added to the soap. Soap requires relatively high-grade raw materials. For example, using butter or palm oil mixed with coconut oil, the prepared soap is crushed and dried to a moisture content of about 10 to 15%. After adding the flavor and dye, it is pressed and formed.
Liquid potassium soap is often used as a shampoo, etc., usually made from coconut oil.
Soap is usually divided into three types: hard soap, soft soap and fat soap. If some drugs are added to the soap, it becomes a medicated soap, such as sulphur soap, sandalwood soap, and the like.
Hard soap is often said to be a “smelly soap”. It has a high alkali content and strong degreasing ability, but it also has a great irritating effect on the skin. When used repeatedly, the skin can quickly dry, rough, peel and so on. . Therefore, hard soap is generally only used for laundry, not for bathing.
Soft soap is the “scented soap” we usually use. It has a low alkali content and is less irritating to the skin, so both normal people and psoriasis patients can be used. It has good anti-dandruff effect on skin lesions.
Fatty soap is also called fatty soap and does not contain alkali. Children’s soaps fall into this category. Suitable for female patients.
Stone carbonate soap, sulfur soap, coal tar soap, boric acid soap, lysine soap, sandalwood soap and other medicated soaps can also be used for patients with psoriasis. However, if the patient is allergic to a certain medicated soap, it should be avoided.
In Chinese detergents, there is still a certain market demand for fragrant soaps. Especially in rural areas and remote areas, people still use soaps for washing and bathing. In China with a large population, considering all aspects, soaps and soaps are never The fleeting products should still be developed and improved accordingly. In the past 10 years, Chinese synthetic detergents have been increasing at an annual rate of 8%. Therefore, Chinese detergents, especially various synthetic detergent products, are still optimistic for the foreseeable future.