Types of testing methods for defoamers

Before using defoamers, it is necessary to test them first, otherwise improper selection may result in failure to achieve the desired effect and even cause certain harm. We can conduct qualitative or quantitative tests on the performance of defoamers according to actual needs. There are many testing methods for defoamers, and we will not list them one by one here. We will mainly introduce several of the most commonly used methods.

1、 Shake bottle method:

The simplest and most common method is the bottle shaking test method. Add a certain amount of foaming liquid into the measuring cylinder with a stopper. After shaking the bottle up and down for the same number of times, stand still and observe the foam height and defoaming time.

2、 Spray test:

Spray bubble solution to create bubbles, and then add defoamer to measure the defoaming effect based on the defoaming time.

3、 Circulating pump test:

Put the bubble solution in the closed loop for circulation, add defoamer for stirring, and measure the foam height. This method is to test the quantitative evaluation of foam inhibition performance under the dynamic state of stirring, emulsification and shearing. When the solution circulates in the closed loop, measure the time required to reach a certain foam height to evaluate the defoaming efficiency.

4、 Density meter measurement:

Measure the density of the foam liquid mixture using a density meter, and represent the foaming amount by the difference between this density value and the density of the foam liquid before stirring. The larger the density difference, the higher the gas content in the foam liquid mixture, and the greater the foaming force. The foaming rate is represented by the percentage of density difference to the density of the foam liquid before stirring; The difference between the foaming amount of the slurry after adding the defoamer and the foaming amount of the blank slurry is the foam inhibition amount, and the foam inhibition rate of the defoamer is obtained by comparing it with the foaming amount of the blank slurry.