Plastic can be divided into two main categories, namely, thermoplastic and thermosetting plastic. Thermoplastic plastic is formed by heating several times and then back to plastic, which is often used to make frames, such as cellulose nitrate, celluloid, Celluloid Dreams, casein Faso, cellulose acetate, vinyl resin, and acrylic acid, etc.; thermosetting plastic, once turned into a shape after heating, it cannot be back to the plastic state.
