What is the foaming principle of blowing agent?

The foaming principle of a blowing agent is a process that utilizes the gases in the blowing agent to expand the volume of the material and form a porous structure when released by heat or by an activator. Specifically, the gas in the blowing agent expands rapidly when stimulated by heat or chemical reaction in the material, causing the material to increase in volume and form a porous structure. The gas in the blowing agent can be an inert gas, such as nitrogen, carbon dioxide, etc., or an active gas, such as ammonia, hydroxides, etc. The foaming principle of the blowing agent is mainly the following:

1. Physical foaming: the use of high temperature, high pressure and other physical conditions to expand the gas to produce a porous structure, such as the preparation of polyurethane foam.

2. Chemical foaming: the use of chemical reactions to produce gas expansion to produce a porous structure, such as the preparation of polystyrene foam.

3. Biological foaming: the use of microbial metabolism to produce gas expansion to produce a porous structure, such as the production of fermented bread.

4. Gas-phase foaming: the use of gas-phase adsorption and expansion to produce a porous structure, such as the preparation of foam glass.

It should be noted that different types of foaming agents have different foaming principles and application scope, the specific use of the need to assess and select according to the actual situation, and at the same time need to be used in accordance with the instructions on the guide, to avoid harm to the human body and the environment.