A retarder is an additive that reduces the hydration rate and heat of hydration of cement or gypsum, and prolongs the setting time There are two main types of retarders: cement mortar retarders and gypsum retarders. Its main function is to reduce the solubility of hemihydrate gypsum; Delaying the dissolution rate of hemihydrate gypsum; Slow setting ions adsorb onto the surface of dihydrate gypsum crystals and bind these ions into the lattice; The retarder forms a complex with ions in gypsum, limiting the diffusion of ions towards the vicinity of dihydrate gypsum crystals.
At present, with the booming development of the construction industry, gypsum products are widely used in many fields such as wall materials and decorative products due to their unique advantages, such as light weight, fire resistance, sound insulation, and adjustable indoor humidity. Gypsum retarder, as a key additive in the production and application of gypsum products, plays an indispensable role.
In fact, this is due to the fast solidification and hardening speed of gypsum materials during the hydration process, which undoubtedly poses great challenges to construction operations. The emergence of gypsum retarder has effectively solved this problem. It can delay the hydration process of gypsum, prolong the setting time, and strive for sufficient operating time for construction, ensuring the quality of the project.
The main applications of gypsum retarder in the construction industry are as follows:
- Gypsum-based plaster
The rapid setting of plaster often limits the flexibility of construction. By adding gypsum retarder, the operable time of Gypsum-based plaster can be significantly extended, avoiding cracking and surface defects caused by rapid setting. In addition, retarders can improve the adhesion and surface hardness of gypsum, ensuring the aesthetic and durability of the final product.
- Gypsum board
Gypsum board are widely used in modern buildings due to their advantages such as lightweight, thermal insulation, and fire resistance. Gypsum retarder can effectively regulate the setting speed of wall panels, allowing them to maintain sufficient time in the mold for molding and curing, thereby improving production efficiency and product quality.
- Self leveling mortar
Self leveling mortar is an important material used for ground leveling. Gypsum retarder prolongs the initial setting time of mortar, reducing construction difficulty and time costs. At the same time, retarders can also prevent cracking and unevenness of mortar during construction, improving the overall flatness and service life of the ground.
- Gypsum putty
Gypsum putty is widely used for leveling and decorating walls. Due to its rapid solidification characteristics, cracking and unevenness are prone to occur during construction. By adding gypsum retarder, the operable time of putty can be significantly extended, making it more stable during construction and avoiding cracking and surface defects.
In the international market, Plast Retard PE produced by SICIT in Italy is a high-performance gypsum retarder. In addition, there is also the Swiss Sika 200p gypsum retarder. However, our product GYPSTAR ® Gypsum retarder are equivalent to both mentioned above.
The commonly used gypsum retarders are mainly metamorphic protein, citrate, tartrate, etc. Although these retarders can effectively prolong the opening time of gypsum products, they can also affect the later strength of gypsum products. With the improvement of the quality of gypsum based products, the adaptability of gypsum retarders to gypsum is becoming increasingly important. Choosing suitable gypsum retarders is crucial for enhancing the comprehensive performance of gypsum based products.
Our GYPSTAR ® gypsum retarder series product’s chemical based is modified amino acids. Compared with citric acid and tartaric acid products, the retarding effect of gypsum is not only better, but also has the least impact on gypsum strength.
Compared to foreign brands, we highly recommend GYPSTAR ® G20 and GYPSTAR ® G300,it can effectively prolong the setting time, and especially GYPSTAR ®G20 can achieve the expected effect with only a small dosage added.
As a leading producer and supplier in the industry, Celotech has over 15 years of production and sales experience. Our professional technical team is always providing customers with any technical support to help them achieve the best performance of their products. At the same time, we actively optimize formulas for customers, increase product added value, and save various costs to some extent. Please feel free to contact us at any time. If you have any needs, we are always ready to provide you with a perfect product customization solution.
