Effect of defoaming agent on self-leveling performance of gypsum


Release time:

2020-05-22

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Effect of defoamer on self-leveling performance of gypsum
 
Defoamer is a suitable powder coating and cement and gypsum-based dry-mixed mortar products, by a variety of organic polymer compounds and surfactant reaction, combined with a special carrier, the use of advanced production technology and equipment. It has the characteristics of easy dispersion, rapid defoaming, high stability, strong adaptability, good compatibility and low addition amount. The defoamer can defoam the microbubbles generated in the construction or production of building materials, so as to achieve the smooth surface of the finished product, the internal structure is dense, and the product performance is improved; and the product has excellent durability and shear stability and increase strength.
 
In the construction, due to dry powder and water mixing, often produce bubbles, affect the aesthetics of the product. Adding a proper amount of dry powder defoamer can effectively eliminate bubbles and pinholes in dry powder mortar products, and eliminate the pores and cavities generated during scraping and spraying, and can improve the impermeability of the product and increase the strength.
 
Dry powder defoamer advantages:
1. Excellent anti-foam effect, inhibiting the material in the mixing process of bubbles.
2. Good diffusion and permeability, rapid defoaming, smooth surface of the finished product, compact internal structure, and remarkable effect of improving product performance.
3. Strong adaptability and good compatibility with other admixtures.
4, chemical stability, does not affect the basic properties of the foaming system, and makes the product have excellent durability and shear stability and increase the strength of the finished product.
5. The effect of eliminating (suppressing) bubbles is obvious, the addition amount is low, and the production cost is reduced.
6, high safety, not dangerous goods.
 
Mortar containing the right amount of size and uniform distribution of closed stable small bubbles, will greatly improve the mortar freeze-thaw resistance, wear resistance, durability and resistance to dry shrinkage and other properties, but uneven or unstable bubbles will not only make the self-leveling mortar surface rough, but also greatly affect its strength and other properties. Choosing a suitable defoamer can accelerate the rupture and elimination of unstable large bubbles, make the bubbles uniform, and improve the performance of the mortar from the surface. This is because the defoamer is also a surfactant, which can not only eliminate bubbles in the mortar, but also stabilize the bubbles.
 
After adding defoamer to the gypsum-based self-leveling mortar system, the fluidity of the self-leveling mortar can be increased, the apparent state of the mortar after hardening can be improved, and the wet density of the mortar can be increased, so that the compressive and flexural strength of the self-leveling mortar after hardening can be significantly improved. At present, the powder defoamers used in mortar products are mainly imported composite defoamers, and there are differences in the suitability of different brands of defoamers in the same mortar product, resulting in differences in the performance of mortar products. The selection of suitable defoamers in the mortar products that need to be applied with defoamers is of great help to the improvement of the comprehensive performance of the mortar.
 

Key words:

Defoamer