PBT（Polybutylene Terephthalate Series）

The main raw materials are terephthalic acid and butanediol monomers. They undergo esterification to form BHBT first, and then polycondensation to obtain PBT. Often, PBT is modified for use in engineering plastics, fibers, electronics, and electrical fields.

Production facilities are categorized into batch and continuous types. The batch type mainly includes single-reactor and double-reactor systems. Continuous production primarily employs three-reactor and four-reactor processes, which generally produce a small amount of THF as a byproduct.