Polyvinyl chloride has abundant raw materials, low price, good performance and wide range of uses. When polyvinyl chloride is used as a plastic, various additives such as stabilizers, plasticizers, lubricants, fillers and pigments are often added according to different properties and uses. Hard PVC plastics can be used to manufacture various devices and profiles, and are often processed to produce corrosion-resistant pipes, valves, ventilation equipment, window frames, furniture, and agricultural products for chemical production. Plasticized soft PVC can be used to make wires, cables, and hoses. Calendered into a film can be made into daily necessities such as raincoats, toys, packaging materials, and agricultural greenhouse covering materials. Foam PVC can be used to make plastic floors, shoe soles, life-saving equipment and heat and sound insulation materials. PVC foam artificial leather can be used as a leather substitute to make imitation leather tops, sandals, etc. PVC thermoplastic elastomer can be used to make automobile shields, bushings, and container door sealing materials. PVC fiber (also known as polyvinyl chloride) can be used to make work clothes, filter cloth, carpets, tents, etc. The knitted underwear made of knitted underwear has certain auxiliary effects on rheumatoid arthritis.