How to distinguish the good and bad quality of redispersible latex powder?

Redispersible latex powder is the main organic binder in the mortar of the external wall insulation system, which ensures the strength and comprehensive performance of the system in the later stage, and makes the entire insulation system blend together. It is also widely used in other building materials such as external wall insulation mortar and high-grade putty powder for external walls. Improving construction and improving flexibility is also crucial to the quality of mortar and putty powder.

However, as the market becomes more and more competitive, there are a lot of mixed products, which have potential application risks for downstream mortar and putty powder customers. According to our understanding of the products and experience analysis, we can use the following methods to initially distinguish between good and bad. Thank you Please refer to.

1. Observe the appearance

Abnormal color; impurities; particularly coarse particles; abnormal smell. The normal appearance should be white to light yellow free-flowing uniform powder without irritating odor.

2. Check the ash content

If the ash content is high, it may contain improper raw materials and high inorganic content.

3. Check the moisture content

There are two cases of abnormally high moisture content. If the fresh product is high, it may be due to poor production technology and improper raw materials; if the stored product is high, it may contain water-absorbing substances.

4. Check the pH value

If the pH value is abnormal, there may be a process or material abnormality unless there are special technical instructions.

5. Iodine solution color test

When the iodine solution encounters starch, it will turn into indigo blue, and the iodine solution color test is used to detect whether the rubber powder is mixed with starch.

operation method

1) Take a small amount of redispersible latex powder and mix it into the water of the plastic bottle, observe the dispersion speed, whether there are suspended particles and precipitation. In the case of less water and more rubber powder, it should be dispersed quickly and there should be no suspended particles and sediment.

2) Add a small amount of water to the redispersible latex powder and spread it with your fingers. It should feel fine and grainy.

3) Spread the redispersible latex powder with a small amount of water, let it dry naturally to form a film, and then observe the film. It should be free of impurities, tough and elastic. The film formed by this method cannot be tested for water resistance because the protective colloid has not been separated; after cement and quartz sand are mixed into the film, the protective colloid polyvinyl alcohol is saponified by alkali and is adsorbed and separated by quartz sand. The water will not disperse again, and the water resistance test can be done.

4) Make experimental products according to the formula and observe the effect.

The redispersible latex powder with particles may be mixed with heavy calcium, and the one without particles does not mean that it is not mixed with anything, and the one mixed with light calcium cannot be seen when it dissolves in water.