In the production and construction processes of the construction industry, the foam problem has always been a major challenge for practitioners. Whether it is concrete mixing, mortar preparation, or the use of materials such as putty powder and waterproof coatings, the generation of foam not only affects the material performance but also may reduce construction efficiency and even impact the overall quality and durability of buildings. The emergence of building chemical powder defoamers provides an effective solution to this problem.
1. Principle of Action
Building chemical powder defoamers are usually compounded from various components such as silicone compounds, mineral oils, and surfactants, with inorganic powders as carriers. Its action mechanism is mainly based on reducing the surface tension of foam. After the defoamer is added to the building material system, its active ingredients disperse rapidly. Hydrophobic particles such as polyether – modified siloxanes will adsorb on the foam surface, the elastic film of the foam, reduce the local surface tension of the foam, and then cause the foam to burst, achieving the defoaming function. At the same time, some components can also inhibit the generation of new foam for a certain period of time, achieving the antifoaming effect.
2. Extensive Application Scenarios
(1) Concrete and Mortar
In concrete production, powder defoamers can effectively eliminate the air bubbles introduced during the mixing process, reduce the internal pores of concrete, and improve the compactness, compressive strength, and impermeability of concrete. For various mortars, such as ordinary cement mortar, self – leveling mortar, tile adhesive mortar, etc., the defoamer can avoid defects such as pinholes and honeycombs on the surface after hardening, improve the surface smoothness and aesthetics, and ensure that the bonding performance of the mortar is not affected by bubbles.
(2) Putty Powder and Coatings
If there are a large number of bubbles in the putty powder during the construction process, it will lead to an uneven wall surface, affecting the painting effect of the subsequent coatings. The powder defoamer can make the putty powder smoother during troweling, eliminate bubbles, and ensure the fineness of the wall surface. In coatings, it can prevent the residue of bubbles, make the coating uniform, and enhance the adhesion and weather resistance of the coating.
(3) Thermal Insulation Materials
In the production of thermal insulation materials such as polystyrene boards and rock wool boards, the use of powder defoamers helps to remove the bubbles in the slurry, making the structure of the thermal insulation materials more uniform, improving the thermal insulation performance, and at the same time preventing local defects caused by bubbles from affecting the material strength.
3. Unique Advantages
(1) High Efficiency
At a very low addition amount (usually 0.1% – 0.5% of the total weight of building materials), building chemical powder defoamers can play a significant defoaming and antifoaming role, greatly improving production efficiency and reducing production costs.
(2) Good Stability
This type of defoamer has good chemical stability and can maintain stable performance under different temperature, pH, and other conditions. Whether it is concrete pouring in a high – temperature environment or a cement mortar system with a strong alkalinity, it can effectively play a role.
(3) Convenient Storage and Transportation
The powder form makes it less likely to leak during storage and transportation. Compared with liquid defoamers, it occupies less space, is easy to manage and use, and is especially suitable for large – scale building material production enterprises and construction sites.
(4) Strong Compatibility
It can be used in combination with various building additives such as water – reducing agents and cellulose ethers. It will not affect the functions of other additives or have a negative impact on the original performance of building materials, ensuring the integrity and stability of the building material formula.
4. Precautions for Use
When using building chemical powder defoamers, it is necessary to fully mix them with the dry powder of building materials to avoid excessive or insufficient local defoamer concentration, which may affect the consistency of the defoaming effect. In addition, different formulations of building materials may require experiments to determine the optimal defoamer dosage to achieve the best defoaming effect without affecting other properties of the materials, such as fluidity and setting time.
With the continuous improvement of the requirements for project quality in the construction industry, building chemical powder defoamers, as key additives to improve the performance of building materials and construction quality, are playing an increasingly important role. Their high – efficiency, stable, and convenient characteristics make them an indispensable part of the construction industry, providing a strong guarantee for creating higher – quality and more durable construction projects.
