Expandable polystyrene is a kind of polystyrene product with foaming agent. Abbreviated code "EPS". The appearance is colorless and transparent bead like particles. As a thermoplastic foam, the expandable polystyrene EPS (Expandable Polystyrene) has undergone a long development process. In 1925, Germany began to produce styrene. At that time, as an intermediate of rubber, it laid a foundation for the production of polystyrene; In 1930, suspension PS came out; In 1943, DOW chemical company of the United States took the lead in putting PS foam into industrial production. In 1949, Japan successfully developed extruded polystyrene foam (XPS) and used for product packaging. EPS products first appeared in the German plastics trade fair in 1952.