Plastic sunglasses are mainly made of synthetic resin. According to its nature, it can be roughly divided into two major categories of thermoplastic and thermosetting resins. The thermoplastic resin can be repeatedly heated and reshaped, and the frame made of such materials is easy to shape the lenses ring and the temple. Thermosetting resins can no longer be reshaped after they are formed, so they are often mixed with thermoplastic materials.