The main applications in which the thermoplastic polyester polybutylene terephthalate (PBT) is used are tightly-toleranced technical parts that are required to withstand high mechanical, electrical and thermal loading. Growth is running at an above-average level of 7 to 9 % per year worldwide. The driving forces behind this growth include new halogen-free, flame-retardant grades for the electrical/electronics industry, grades with enhanced hydrolysis resistance and customised compounds for interior and exterior automotive applications.