Views: 159 Author: Yida Cellulose Publish Time: 31-05-2022 Origin: Site
Content
Most common retarder in gypsum
There are three main types of commonly used retarders:
Organic acids and their soluble salts
Alkaline Phosphate
Protein retarder.
Organic acids and their soluble salt retarders mainly include citric acid, sodium citrate, tartaric acid, potassium tartrate, acrylic acid and sodium acrylate, among which citric acid and its salts are the most studied and the most effective.
Citric acid and its salts can achieve a strong retardation effect when the dosage is very small.
The function of retarder in gypsum is to delay the setting time of gypsum and improve the strength of gypsum. Gypsum retarder can control the setting time of gypsum and keep it fluid for a certain period of time, which can greatly reduce the waste and loss of gypsum and improve the construction efficiency.
1. The selected amount of retarder must be mixed with gypsum powder evenly, or the gypsum powder must be added after the retarder is completely dissolved in water.
2. The amount of gypsum retarder added is determined according to the initial setting time of the gypsum powder itself. If the initial setting time is long, an additional amount of retarder is required.
3. The addition amount of gypsum retarder is determined according to the proportion of gypsum powder in the gypsum mortar. If the proportion of gypsum powder is large, the amount of retarder needs to be added.
4. The amount of gypsum retarder added is determined according to the operation time required for the gypsum mortar. If the operation time is long, the amount of retarder needs to be added.
5. The recommended dosage of this product is 0.5-3‰ of the system, and the dosage needs to be determined by experiments
Most commonly used retarder in gypsum is Citric acid gypsum retarder.However, it is not that the composition of retarder for gypsum plaster
is only citric acid. After the gypsum powder was mixed with citric acid, the dry and wet strengths of the gypsum samples were greatly reduced. The dry flexural strength decreases sharply when its content is greater than 0.07%; the dry compressive strength decreases sharply when its content exceeds 0.05%; and the wet flexural strength decreases almost linearly, when the content is 0.1 %, the wet flexural strength of mold gypsum is only 0.5MPa. Only using citric acid has too much influence on the strength of gypsum powder after solidification, and it is difficult to control. Therefore, citric acid is generally not used alone as a retarder for gypsum plaster.
YIDA is a gypsum retarder manufacturer with 16 years of experience. The annual output of retarder for gypsum products is 20,000 tons. According to your gypsum powder products, the optimal use method of retarder can be formulated.
