Can be divided into rigid foam, flexible foam semi-rigid (or semi-soft) foam. The core foam is also called porous plastic, which is made of resin as the main raw material and has numerous microporous plastics inside. Widely used as insulation, sound insulation, packaging materials and car shells.

Core foams are classified into soft, hard and semi-rigid foams in between depending on their flexibility. Rigid foam can be used as thermal insulation materials and sound insulation materials, insulation materials for pipes and containers, floating materials and shock absorbing packaging materials; flexible foams are mainly used as cushioning materials, foam artificial leather and so on. Commonly used foams are polyurethane, polystyrene, polyvinyl chloride, polyethylene, phenolic foam, and the like.

Core foam is also called porous plastic. A resin made of resin as the main raw material with numerous micropores inside. Light weight, heat insulation, sound absorption, shockproof and corrosion resistant. There are soft and hard points. Widely used as insulation, sound insulation, packaging materials and car shells.

Compared with pure plastics, core foams have low density, light weight, high specific strength, increased strength with increasing density, ability to absorb shock loads, excellent cushioning and shock absorption, sound insulation and sound absorption, heat. Low conductivity, good thermal insulation performance, excellent electrical insulation performance, corrosion resistance and mold resistance. The flexible foam has excellent properties such as elasticity.

The content has a lot of tiny pores of plastic. It is obtained by a mechanical method (either by air or carbon dioxide while mechanical agitation) or by a chemical method (adding a foaming agent). There are two types of closed-cell type and open-hole type. The pores in the closed-cell type are isolated from each other and have a floating property; the pores in the open-hole type are connected to each other without floating. It can be made of resin such as polystyrene, polyvinyl chloride or polyurethane. It can be used as insulation and sound insulation material for a wide range of applications.