What is plastic foaming agent?

Foaming agent is a kind of additives that can form a cellular structure in plastics. They can 

produce a large number of gases under specific conditions, in the formation of these

containing continuous or discontinuous pores (i.e. open or closed holes), so that the plastic

formed a gas-solid bonded porous structure material, which can reduce the density and

hardness of the plastic, or enhance its sound insulation and heat insulation.

According to the different ways of producing gas, foaming agents can be divided into physical 

foaming agents and chemical foaming agents.

Physical foaming agent

The foam pore is formed by the change of physical form of a substance, such as the expansion 

of compressed gas, the volatilization of liquid or the dissolution of solid.

Physical foaming agents include aliphatic hydrocarbons such as pentane and heptane.

Chemical foaming agent 

Chemical foaming agent is also called decomposition foaming agent. They can be evenly

dispersed in resins and decomposed by heat to produce at least one gas. It can be divided

into inorganic foaming agent and organic foaming agent. Organic foaming agents are the

main foaming agents used in plastics, mainly azo, nitroso and sulfonyl hydrazide. In addition, 

there are some foaming agent components whose foaming gas is released by endothermic

reaction between the two components. Inorganic foaming agent mainly refers to sodium bicarbonate