Deepen the defoaming field, assist in efficient production, and provide one-stop foam solutions
Welcome to Nanjing Golden Key Biotechnology Co., Ltd.!
Two Common Methods of Adding Silicone Antifoams
Release Date:
2021-12-27
As a defoaming agent, silicone‑based defoamers must be insoluble in the foaming medium and can be dispersed into the foaming system in various forms. They are formulated by mechanically emulsifying silicone oil, precipitated silica, emulsifiers, dispersants, preservatives, thickeners, and an appropriate amount of water. Their key characteristics include low surface tension, high surface activity, strong defoaming performance, minimal dosage requirements, and low cost. They effectively eliminate and inhibit foam across a wide range of foaming media. Moreover, silicone‑based defoamers exhibit excellent thermal stability, making them suitable for use over an extensive temperature range from –5°C to –150°C.
As a defoaming agent, silicone‑based defoamers must be insoluble in the foaming medium and can be dispersed into the foaming system in various forms. They are formulated by mechanically emulsifying silicone oil, precipitated silica, emulsifiers, dispersants, preservatives, thickeners, and an appropriate amount of water. Their key characteristics include low surface tension, high surface activity, strong defoaming performance, minimal dosage requirements, and low cost. They effectively eliminate and inhibit foam across a wide range of foaming media. Silicone‑based defoamers also exhibit excellent thermal stability, making them suitable for use over an extensive temperature range from –5°C to –150°C.
So, when should a defoamer be added? Below, we’ll introduce two common methods for adding silicone‑based defoamers:
I. Continuous Dropwise Addition
When the defoaming liquid is in a bubbly state, or under conditions of circulation or flow, the continuous circulation of the foaming liquid will deplete the defoamer. In such cases, employing a method of continuously dosing the defoamer allows it to effectively suppress foam. When combined with a metering pump, this approach also enables precise control of the dosage, thereby achieving cost‑effective use of the defoamer.
II. Add before foaming
This method suppresses foam formation by adding a defoamer in advance to systems prone to foaming. In closed vessels and equipment, defoamers can effectively eliminate foam.
Things to note before adding:
1. Whenever possible, use a thickener to dilute the product. Silicone‑based defoamers can be diluted, but such dilution will significantly reduce their stability; if layering occurs, this is undesirable. Therefore, we recommend using a thickener for dilution. If water is used for dilution, add the water to the defoamer while stirring slowly, and use the diluted solution on the same day it is prepared.
2. Before use, thoroughly stir the emulsion to ensure uniformity. Inhomogeneity can lead to layering, which may compromise the performance of the defoamer.
3. Prevent frost damage. Silicone-based defoamers are highly sensitive to both freezing and excessive temperatures, making them prone to degradation. If a defoamer has already frozen, it must be carefully thawed, and its performance should be tested before use.
Domestic Business Department
13770937137(Ms. Ge)
No. 5, Lingxiao Road, Lukou Subdistrict, Jiangning District, Nanjing City
Foreign Trade Department