Polyethersulfone (PESU) is an amorphous thermoplastic specialty engineering plastic. It exhibits excellent creep resistance and dimensional stability at high temperatures. PESU offers outstanding heat resistance, high mechanical strength, and is suitable for food contact applications. Notably, it can be used continuously at high temperatures and maintains good dimensional stability even in environments with sudden temperature changes.

When reinforced with 30% glass fiber, deformation under high load at 200°C over four months is less than 0.005%. If a 50% reduction in tensile strength is considered the threshold for continuous service life, PESU can be used for 20 years at 180°C and for 5 years at 200°C. Therefore, the long-term use temperature of PESU is considered to be 180°C, or 200°C when reinforced with 30% glass fiber.