Ovens for Post-curing of Torlon® Polymers

Torlon® polyamide-imide (PAI) is a plastic with the highest strength and stiffness of any available thermoplastic up to 275°C (525°F). Torlon® has outstanding resistance to wear, creep and chemicals—including strong acids and most organics—and is ideally suited for severe applications such as aircraft and automobile components, electric motors, oil and gas processing equipment, gears, bushings, seals and thrust washers.

Torlon® parts, as molded, are relatively weak and brittle and have low chemical, wear and thermal resistance. After molding, Torlon® parts must be heat-cured in a forced-air oven at specific temperatures for specified times. This increases the molecular weight of the polymer through a chemical reaction called “chain extension” and dramatically increases the material’s tensile strength, toughness and wear resistance. This heat-curing, often referred to as a “cure schedule” or a “cure cycle”, is critical in obtaining optimum mechanical, chemical and thermal properties.

The Torlon® curing cycle can be a relatively long process—17 days or more—and requires a reliable oven capable of maintaining 260°C (500°F) with a maximum temperature differential of less than 5.6°C (10°F). Despatch offers the RA Series of Reach-in Ovens as the ideal solution for heat-curing post-molded Torlon® parts. Despatch cabinet ovens features horizontal recirculating airflow with temperature uniformity of ± 3.4˚C or better at 260˚C. The standard Protocol 3™ communication controller and Protocol Manager™ communication software provide the accurate program time and temperature settings required for successful cure cycles. Multiple temperature operations are controlled by up to eight programs, with eight ramp and soak segments in each program. The Ovens also have standard end-of-cycle and high-limit controls as recommended for post-curing of molded Torlon® polymers.