What is gypsum ?

Gypsum is one of the most widely used building materials, which is created from the gypsum rock found in nature. Gypsum is also used in various industries such as ceramics, porcelain, crystallization, medicine, etc. In this article, we are going to talk about plaster and its benefits and applications in a specialized manner.

What is gypsum?

Gypsum is produced from natural gypsum. Gypsum, or hydrated calcium sulfate, has different crystalline forms and is white in color. Raw gypsum stone is transported to the factory after being extracted from the mine, and after being granulated, it goes to the furnace and is heated up to 180 degrees so that the water molecules in the gypsum stone evaporate and lose its crystallization, and then it is milled. and it turns into plaster powder and is suitable for use in construction and molding industry. The production stages of building plaster are divided into the following ten stages.

The explosion of raw gypsum

Transfer to the factory

chopping

to cool

Baking and seeing plaster

dusting

Grind

to save

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What are the characteristics of plaster?

Advantages of using plaster

It is easy to set compared to other building materials

Fire resistant

High resistance

In terms of price, it is more affordable than other materials

Increase in volume of plaster after mixing with water

Color-able

being acoustic

Types of building plaster

After mining, gypsum stone goes to the factory and white gypsum is produced in a process. When in the factory, whitening plaster is combined with additives and seen in thermal furnaces or cooled by more advanced mills, different types of plaster are produced.

Whitening plaster (Type 1): Plaster Type 1 is used for whitewash inside the building

Ready-made soil plaster (Kimia): This plaster has very fine and fine granulation in microns. And it is used in medical, industrial and sculpture industries.

Concrete coating (Gypton): Gypton plaster is created from the combination of white plaster with adhesive additives and is applied on concrete, cement and brick surfaces.

Base coat plaster (Royal): This type of plaster without molecular water is mixed with a solution and then baked again. The plaster Royal has a high resistance to moisture.

Finishing plaster (Super): This type of plaster is produced by combining white plaster with additives such as perlite, which is used to whiten the final layer of surfaces.

How to use plaster

To use plaster in the building, you must first pour the plaster in a container and then add water to it. The ratio of plaster to water must be proportional. For example, for every 10 kg of plaster, 10 kg of water should be added to it.

Then we give time to the mixture for 1 or 2 minutes and then we stir the mixture by hand or mixer until it is completely uniform. After that you have about 5 minutes to use the mortar.

The movement of the trowel should be diagonal to the wall because the side line of the trowel can create a smooth and even surface.

Application of plaster

Gypsum in industrial industries, the important applications are

Construction: for making mortar, increasing cement setting time, whitening, plastering and finishing

Porcelain making and ceramic making: for making porcelain and ceramic molds

Glazing: To adjust the viscosity of the liquor

Casting: To make a casting mold

Agriculture: to prepare chemical fertilizers, soil conditioning and chemical poisons

Medical: for making dental molds, medical bandages, tablets and broken packaging

Paper production: for transparency paper

Tanning: To separate the horny material from the skin

How to make plaster water resistant?

We pulverize anhydrous or dry gypsum completely, then we make it into a paste in a solution of white alum. We take it to the furnace and heat it up to 500 degrees, then we turn it into plaster powder again through the mill. This type of plaster will completely resist moisture and water and will not collapse in the vicinity of water. This type of plaster can also be used on the facade of buildings

Important points regarding the use of plaster

If the amount of gypsum mortar compared to water is less during the preparation of gypsum mortar, the gypsum will crack after drying.

Also, if the thickness of the plaster you draw on the wall is more than 8 cm, the lower layers will remain wet and the upper layers will dry and causes cracking.

One of the problems of plaster is moisture absorption. To increase the durability of the plaster in the parts that are exposed to water vapor a layer of oil paint should be applied on it.

Before you cover the iron and copper surfaces with plaster, you should apply an anti-rust layer on it, because if the plaster is directly on the metal surfaces, sulfate will be produced from the combination of plaster with metals and the life of the piece will be reduced.

Conclusion

Gypsum is obtained from gypsum found in nature and is turned into powder in a factory. Powdered gypsum is one of the building materials. In this article, we tried to introduce plaster completely and introduce you to the types of plaster and their benefits and provide you with useful information about their use.