Deep analysis and Countermeasures of putty foaming

Shandong chuangyao Biotechnology Co., Ltd. is specialized in the field of powder additives. The company has professional researchers and construction personnel. The main products of the company are hydroxypropyl methyl cellulose, redispersible latex powder, hydroxypropyl starch ether and other dry powder building materials additives.

Through the investigation, it is found that the problem of putty foaming often occurs in the use of putty powder, which may be the bubbles generated in the process of putty construction, or the surface of putty will blister after a period of construction. So what is the cause of putty foaming? And how to solve it? Shandong chuangyao Biotechnology Co., Ltd. through a variety of experiments and comparisons, this paper makes a professional summary, hoping to help readers.

1. Air hole bubbling in concrete pouring

Phenomenon:

The bubbles on the base surface not only bulge very high, but also have relatively deep pits after puncturing;

Causes:

The base surface of the putty is cast-in-place concrete wall, and the surface has dense air holes after demoulding. When scraping on such a base surface, the air hole is sealed by the putty paste, and the air in the air hole is compressed, which will form the accumulated potential energy; then when the scraper leaves the air hole, the putty paste body is rebounded and pushed up by the air sealed and compressed in the air hole to form bubbles;

Solution:

It can be solved by scraping the first time with coarse putty with low viscosity (hydroxypropyl methyl cellulose with low viscosity can be added to putty powder) or plastering for the first time with gypsum which can be quickly formed and does not rebound.

2. Blistering of rough mortar base

Phenomenon:

Putty scraping up from dense and small bubbles;

Causes:

The surface of mortar is too rough and there are many small pits. When putty is applied, the air in the small pit is compressed, and the air can not be effectively discharged. After the pressure is released, the putty film is jacked up to form bubbles;

Solution:

Roll a layer of liquid interface agent or coarse powder interface agent with a roller, and then apply relatively coarse putty after drying. (instant high viscosity hydroxypropyl methyl cellulose can be used for roughing)

3. There is floating ash or powdering in the base course, resulting in foaming

Phenomenon:

Generally, it is bubbling or bubbling;

Causes:

The base course is powdered or there is a large amount of floating ash, which can not be effectively bonded after applying putty, and bulge or blister occurs;

Solution:

In this case, it is necessary to clean the base course, remove the floating ash or remove the weak base before applying putty.

4. The second layer of putty foams

Causes:

In this case, the first layer of putty has not eliminated the bubbles. When scraping the second layer of putty, we habitually take a shovel to flatten the first layer of putty, and then break the first layer of air bubble. It is the same reason that a new bubble continues to appear on the first air hole;

Solution:

At this time, do not shovel the first air hole, continue to use leveling putty or plaster thick scraping to cover the first layer of bubbles.

5. Foaming of putty material / formula

Causes:

The use of hydroxypropyl methyl cellulose and redispersible latex powder with high viscosity and easy air entrainment leads to strong film-forming property of putty layer, and the base gas is sealed and bubbles cannot be eliminated. In addition, some poor quality lime contains a large amount of quicklime, after adding water, it will produce a large amount of gas and cause foaming.

Solution:

Redispersible latex powder and hydroxypropyl methylcellulose with moderate viscosity and low air entrainment, as well as high-quality gray calcium products, were selected. The putty was stirred and left for about 10 minutes before scraping.

6. Bubbles in concrete ceiling base

Phenomenon:

Generally, there will be a big bubble or empty drum;

Causes:

The base course of concrete ceiling is smooth and inconvenient for construction, and the application force is uneven, which leads to the putty layer can not be firmly bonded. In addition, the gravity of putty layer itself leads to foaming;

Solution:

It is suggested that the interface treatment should be done before the putty is applied. After the putty is completely dried, the putty with low viscosity and strong flexibility should be applied. (it is suggested to add hydroxypropyl methyl cellulose with 50000 viscosity and flexible redispersible latex powder)

Please contact Shandong chuangyao Biotechnology Co., Ltd. for more information on putty powder, cheongsam and product HPMC and redispersible latex powder. The company will have professional technical personnel to answer for you.