跳至主要内容

Why use defoamer for waterproof paint and how to use defoamer correctly?


Why use defoamer for waterproof paint and how to use defoamercorrectly?

What is waterproof paint?

Waterproof paint is a kind of paint that can prevent rain or groundwater from leaking.
Acrylic waterproof coating is a one-component water-emulsion waterproof coating made by using acrylic polymer emulsion as the base material and adding other auxiliary additives. The waterproof film formed after the waterproof coating is cured has certain extensibility, elastoplasticity, crack resistance, impermeability and weather resistance, and can play the role of waterproof, impermeability and protection. The waterproof coating has good temperature adaptability, easy operation and easy repair and maintenance.

The performance indicators of waterproof coatings are as follows:

Solid content

Solid content refers to the proportion of solids contained in a waterproof coating. Because the coating is formed by the solid components in the coating after brushing, the solid content is closely related to the thickness of the film and the quality of the coating.

Heat resistance

Heat resistance refers to the fact that the waterproof film after the waterproof coating is formed does not soften and deform at high temperatures. Non-flowing performance, ie high temperature resistance.

Flexibility

Flexible refers to the ability of the film layer of the waterproof coating to maintain flexibility at low temperatures. It reflects the application and performance of waterproof coatings at low temperatures.

Impermeable

Impermeability refers to the performance of waterproof coatings under a certain water pressure (hydrostatic pressure or dynamic water pressure) and no leakage in a certain period of time. It is the main quality index of waterproof coatings to meet the requirements of waterproof function.

Extensibility

The ability of the stretch-type waterproof coating to adapt to the deformation of the base layer. After the waterproof coating is formed, it must have a certain extensibility to adapt to the deformation of the base layer caused by factors such as temperature difference, dryness and humidity, and ensure the waterproof effect.
The basic process of acrylic waterproof coating: clean up the base layer → the bottom waterproof layer → the detail additional layer → paint the intermediate waterproof layer → apply the reinforcing layer → paint the intermediate layer waterproof layer → paint the surface waterproof layer → the waterproof layer first water storage Test → Protective layer and finish construction → Second water storage test → Engineering quality acceptance.

Why there are air bubbles in waterproof coatings?

*  Acrylate emulsion contains or has the characteristics of surfactant, and it is easy to generate bubbles.
*  During the construction process, stir the paint evenly and leave it for a short time. Generally, it is used immediately. The air bubbles generated during the stirring process have no chance to escape from the paint and remain in the coating film. Even if the bubbles burst, the coating will lose its fluidity, leaving cracks and pores on the surface of the coating film.
*  In order to ensure that the construction of the waterproof coating is easy and the thickness is not flowing, an appropriate amount of thickener needs to be added to increase the viscosity, which makes it difficult for bubbles to escape to the liquid surface and rupture.
The generation of air bubbles will affect the appearance and waterproof effect of the waterproof coating film. Regardless of brushing or roller coating during the construction process, if the bubbles cannot be eliminated in time, pores and cells of different sizes will be formed inside the coating film. The existence of these cells not only greatly reduces the effective cross-sectional area of ​​the coating film against the action of water pressure, but also generates stress concentration around the cells, causing the cracks to expand, making the waterproof coating film lose the waterproof effect, affecting the waterproof effect of the entire project. Reduce the durability of construction projects.
It is practically impossible to avoid foaming. A more practical and effective method is to add a defoamer to eliminate air bubbles.
Customers must choose defoamer depend on their experiments to evaluate the effects of different types of defoamers. It is known from practice that different combinations of emulsifying systems and auxiliaries will give different results.

https://www.linkedin.com/company/china-defoamer

https://www.facebook.com/invelychem/
标签：

评论

发表评论

此博客中的热门博文

How do we assess antifoam efficiency ?

How do we assess antifoam efficiency ? Quality of an antifoam is given by two main characteristics : • Knockdown ability or shock effect :Meaning the speed to destroy an existing foam. • Persistence or durability : Meaning the efficiency over time.   These two parameters can be assessed by several tests. The main test is the bubbling method. A graduated column with a glass frit in the bottom is required. Foaming water is poured in the column and air at constant flowrate is introduced through the glass frit in the column. Foam is generated by the air and starts to travel up the column. At a determined level of foam, antifoam is injected. By this method several antifoaming agents can be tested. A graph reporting foam height vs time is very helpful to establish the knockdown ability and the persistence for each product. The selected antifoam is the product with the best compromise between shock effect and durability       Environmental performance   Silicone antifo...
1 条评论
阅读全文

What is a defoamer / deaerator’s purpose in the system?

What is a defoamer / deaerator’s purpose in the system? Defoamers prevent formation of foam during manufacture and application of coatings and printing inks. Foam that is already formed is destroyed and air occlusions are prevented. Deaerators prevent development of air occlusions and pinholes. Why use a defoamer? The occurrence of foam is considered an undesirable but unavoidable phenomenon in coatings and printing inks. The formation of foam interrupts production processes, reduces the effective volumes in the production plant, and leads to unnecessary down time. Foam also interferes with the application process. In printing, foam can cause the ink reservoirs to overflow and can impair ink transfer from the printing cylinder to the substrate. Dried foam leaves surface defects in the paint film. To prevent foam and destroy any foam present, defoamers must be added to the formulation. defoamer vs. deaerator? To eliminate macro-foam on the surface, to prevent air occlusions, and...
发表评论
阅读全文

Defoamer Test Method

Defoamer testing methods are divided into dynamic defoaming and static defoaming tests. If your foaming environment is different, the recommended test methods are different. There are three main types of foam experiments to characterize the activity of defoamers. Persistence. As we have different experimental conditions in different laboratories and the experiments used in our research to obtain results from existing literature, we will introduce these experiments below. Other methods are sometimes used depending on the particular application. 1． Ross-Miles Foam Tester   Features: Tested for strong foaming environments. This experiment is widely used for characterization        (1) Foaming of surfactant solution        (2) Research and application of foam stability in the presence of defoamer In the foaming system, the defoaming performance test was carried out by circulating bubbling by a Ros...
发表评论
阅读全文