Three testing methods for defoaming ability of defoaming agents
Different types of defoaming agents have different defoaming capabilities. Below we will introduce three testing methods for the defoaming capability of defoaming agents:
1. Reincarnation Law
The falling height and flow rate of the circulating material are constant, and the height of the material in the receiver is recorded at each time. The air mixing rate is small and the defoaming effect is considered to be good.
2. Vibration method
The paint used was an acrylic latex paint that did not contain defoamer before testing. Add the sample to 1/2 volume of the test tank, and after vibrating for the specified time, measure the density of the defoaming agent. Different from other methods, it is suitable for low viscosity coatings or emulsions.
3. Bubble method
This method is to directly introduce air to make the system generate foam. Add 100ml of the sample into a measuring cylinder with a diameter of 5cm. After adding the defoaming agent, use a quantitative pump to introduce 500ml of air per minute. The temperature is controlled at 30°C. Record the bubble height for a certain period of time. As the industrial construction method of roller coating or shower coating, the remaining paint after coating falls into the receiver for recycling. The time of vibration can be artificially determined by the difficulty of foam generation.
The above are three testing methods for the defoaming ability of defoaming agents. I hope it will be helpful to everyone when choosing defoaming agents.
