Meaning
Semi crystalline thermoplastic polyesters provide excellent electrical insulation and chemical resistance for industrial and automotive applications. This pbt resin is characterized by its high strength and stiffness which remain stable even at elevated temperatures. It is often reinforced with glass fibers to improve its structural properties and dimensional stability during the injection moulding process.
Material Property
Resistance to a wide range of solvents and automotive fluids makes the polymer ideal for under the hood components. A typical pbt resin displays low moisture absorption which prevents the parts from swelling or losing their mechanical integrity in humid environments. This stability ensures that the electrical connectors and housings maintain their tight tolerances throughout the life of the vehicle.
Processing Variable
Rapid crystallization during the cooling phase allows for short cycle times in the moulding press. The processing of pbt resin requires careful control of the melt temperature and the mould temperature to avoid the formation of internal stresses. If the material is not dried properly before moulding, hydrolysis can occur which reduces the impact strength of the finished part.
This degradation is permanent.
Application Boundary
Brittleness in its unreinforced state limits the use of the polymer in parts subject to heavy impact. The choice of this resin is usually driven by the need for a balance between heat resistance and electrical performance. It fails under high shock.
