Generally refers to large output, wide usage, good shape, cheap plastic. General plastics, there are five major varieties, namely, polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS) . Five plastic occupies most of the plastic materials used, the rest can be categorized into special plastic variety, such as: PPS, PPO, PA, PC, POM etc, they are rarely in daily life products, mainly used in the engineering industry, high-end fields such as science and technology for national defense, such as automotive, aerospace, construction, communications and other fields. Classification of plastics according to its plasticity can be divided into thermoplastic and thermosetting plastics. Typically, thermoplastic plastic products can be recycled, but thermosetting plastics cannot, according to the optical properties of plastic, can be divided into transparent, translucent and opaque material, such as PS, PMMA, AS, PC, belonging to transparent plastic, and most other plastic and opaque plastic.