Microsphere Swelling Agent

The microsphere expansion agent, also known as expandable microspheres or thermally expandable microbeads, is a spherical polymer particle with a core-shell structure. The outer shell is made of thermoplastic polymer and has gas barrier properties. The core encapsulates low-boiling-point liquid hydrocarbon foaming agents. When heated to a certain temperature, the outer shell becomes soft, while the liquid foaming agent inside the core vaporizes, generating internal pressure. Under the influence of internal pressure, the softened shell expands, and its volume can increase by several times or even hundreds of times. After cooling, the outer shell solidifies, and the expanded spherical structure is thus fixed in place.