Polymethyl methacrylate (PMMA, commonly known as acrylic) is a non-crystalline thermoplastic plastic formed by the polymerization of methyl methacrylate monomers. It can be regarded as “plastic glass” - it forms long-chain molecules through bulk or suspension polymerization, thus having an extremely high light transmittance (over 92%, even better than ordinary inorganic glass), good weather resistance and surface hardness, and a density only half that of glass. PMMA is not only easy to process (it can be injection-molded, extruded, or cast into complex shapes), but also has excellent electrical insulation and biocompatibility (not irritating to the skin), and is widely used in building light covers, signboards, car tail light covers, aquariums, acrylic bathtubs, display light guide plates, and medical dentures and other occasions that require transparency, beauty, light weight and durability.