Para-xylene is the raw material for producing polyester and polyamide. After oxidation, terephthalic acid (PTA) is produced. PTA, glycol, butanediol and other polyols are used to synthesize various polyester materials. M-xylene is used to produce isophthalic acid, and isophthalic acid can also be used to produce special polyester, and the polyester produced by it has good weather resistance. O-xylene is mainly used to produce phthalic anhydride, which is also a very important chemical raw material and a plasticizer for producing PVC resin. Mixtures of xylenes are used in various solvents, such as paint solvents and chemical production solvents.