The molecular structure of PEEK makes it one of the most robust engineering plastics available today. It can operate continuously at temperatures up to 250°C and tolerate short-term excursions up to 300°C. Beyond heat resistance, PEEK is virtually insoluble in all common solvents. It resists attack from strong acids, alkalis, and hydrocarbons, making it a preferred material for components exposed to harsh chemicals, such as pump seals and valve parts.
In addition to its thermal and chemical resilience, PEEK offers excellent mechanical properties. It has a high tensile strength and flexural modulus, along with outstanding fatigue resistance, which allows it to replace metal parts in many structural applications. Because it is inherently pure and flame retardant (achieving UL94 V-0 rating without additives), PEEK is biocompatible and sterilizable, making it ideal for medical implants, surgical instruments, and semiconductor wafer handling components.
Despite its incredible performance, PEEK presents unique processing challenges. It requires extremely high melt temperatures, typically between 360°C and 400°C, and highly heated molds to prevent premature cooling and internal stress. As a result, specialized high-temperature injection molding machines or precise CNC machining are required. Proper annealing after machining is also crucial to relieve internal stresses, ensuring the final part maintains its dimensional accuracy and mechanical strength in extreme operational environments.