TP (polybutylene terephthalate) is a semi-crystalline engineering thermoplastic material that offers very good chemical resistance along with high levels of mechanical and thermal properties. Polybutylene terephthalate has good dimensional stability and is unaffected by ambient humidity. This semi-crystalline thermoplastic also has low friction and resistance to abrasion. Properties of TP can be further enhanced by the addition of additives.
The rigidity of Polybutylene terephthalate can be increased by the addition of glass fibers in a loading range of 10% to 40%. Flame retardants can be added to TP in order to provide performance profiles required for electrical/electronics applications. Although TP is not as ductile as other materials, such as polycarbonate, impact modifiers can be added in order to provide high impact products. Additives can also be combined to provide products with broad property profiles. Examples of this include flame retardant glass filled TP, and flame retardant impact modified Polybutylene terephthalate.
The semi-crystalline nature of TP causes this material to have both higher shrinkage values, and higher specific gravity values than amorphous thermoplastics. These factors should be taken into account when designing parts.
Additives, Modifiers, and Reinforcing Agents:
Additives- UV stability, easy release (mold releases), colorants, and other stability additives
Modifiers- Flame retardants, impact modifiers, flow enhancers
Reinforcing Agents- Glass fibers, mineral fillers