The use of defoamers in water-based coatings

1、 The importance of defoamers for water-based coatings

During the production, storage and construction of water-based coatings, a lot of foam is often produced due to mixing, mixing and other operations. These foam not only affect the application effect of the coating, but also may reduce the performance of the coating. Therefore, the addition of defoamers is particularly important. It can effectively inhibit and eliminate foam, and improve the working performance and stability of the paint.

2、 Notice before use

When using water-based paint defoamers, the following points should be noted:

1. Adequate mixing: Before use, the defoamer should be thoroughly mixed to ensure even mixing.

2. Timing of addition: Add defoamers in the mixing process of the coating at the appropriate time to achieve the best defoaming effect.

3. No need for pre dilution: Most defoamers do not require pre dilution with water. But if the product manual indicates the need for pre dilution, the instructions should be followed and ensure that it is used as needed.

3、 Usage control

The dosage of defoamer is a key factor in the use process. Insufficient dosage may not achieve the expected defoaming effect, while excessive dosage may cause other problems such as shrinkage, edge shrinkage, poor brushing and recoating properties of the coating. Therefore, the optimal amount of defoamer should be determined through experiments or estimated based on experience.

4、 Join in installments

According to the process conditions, defoamers can be added in two batches. In the pigment grinding stage and the pigment and lotion mixing stage, half of the total amount of defoamer is added each time. This can better control the production of foam and improve the quality of paint. In the grinding stage of pigment slurry, defoamer with good foam inhibiting effect can be added; In the mixing stage, defoamers with good defoaming effects are added.

5、 Time factor

After the addition of defoamers, it takes a certain amount of time to achieve the desired defoaming effect. Therefore, when testing the performance of coatings or carrying out construction, it is necessary to wait for at least 24 hours after adding defoamers. This can ensure that the performance of the coating reaches its optimal state.

6、 Precautions

1. Select appropriate defoamer: select appropriate defoamer according to the paint system and the foam problem to be solved.

2. Follow the product instructions: Before use, carefully read the product manual and follow the instructions for operation.

3. Safe storage: Defoamers should be stored in a cool, dry, and ventilated place, away from sources of fire and oxidants.

In short, the role of water-based paint defoamers in formulations should not be underestimated. Proper use of defoamers can effectively solve the problem of foaming in water-based coatings during production and use, and improve the performance and stability of coatings.