Polyester PBT


PBT is a linear thermoplastic saturated polyester containing ester bonds in its main chain. PBT stands for polybutylene terephthalate. The polymer belongs to the same family as PET resin.

PBT possesses a high melting point and high crystallinity, while low water absorption and thermal expansion coefficient give the resin superior dimensional stability. Electrical properties are also superior, and only small changes in electrical properties are exhibited as a result of moisture absorption. Dielectric breakdown voltage is also high

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Both crystalline and non-crystalline structures coexist in PBT. As a result, additives can be readily employed to improve properties and render functionality. The grade line up includes a variety of grades possessing various features, such as flame retardant grades, fast molding cycle grades, and high impact strength grades.


  • Unreinforced grades have abundant strength and flexibility, and have strong characteristics against brittleness.
  • UL-certified slow-burning (94HB) and self-extinguishing grades (94V-0, V-2) exist, and electrical properties exhibited are the highest of any thermoplastic.
  • Low water absorption is exhibited, and excellent electrical properties are retained over extended periods of usages, even with widely varied temperature and humidity conditions.
  • The surface of molded products is smooth, and a low coefficient of friction is exhibited. As the amount of friction is low, PBT is suitable for use in applications requiring friction and wear properties. The material is exceptionally reliable, with small In-use dimensional variation, and superior molding stability and dimensional precision.
  • Long-term chemical resistance is exceptional, and at room temperature, there is almost no degradation in properties after.
  • Both unreinforced and reinforced grades exhibit exceptional flowability, and excellent processability.
  • Various polymer alloys have been developed through employing compatibilization technology to blend PBT with other polymers in order to achieve the target performance.


PBT is adopted in a wide variety of familiar products used in every day life, such electrical components (connectors, microswitches, and condenser cases, etc.), OA equipments keyboards, VTRs, telephones, auto parts (including in-car electronic products and outer door handles), medical devices, construction materials, and precision equipment..