Celluloid refers to the old brand name used in plastics, and it is the earliest commercialized synthetic plastic. It is a substance formed by adding nitrocellulose and camphor to improve its plasticity. Old melamine plastic belongs to high molecular polymer, and its monomers are formaldehyde and melamine.

Celluloid is mainly used to make table tennis, spectacle frames, toys, pens, architectural decorations, etc. Old melamine is used in chemical industry, packaging, paper making, construction, tableware, furniture and so on.