PTFE vs PEEK

Often chosen for applications in demanding applications across a wide range of industries such as Aerospace, Chemical, Nuclear and Oil & Gas; High-Performance Plastic and Fluoropolymers are generally differentiated by their temperature stability, but also their mechanical properties.

But how do you know whether you should you use PTFE or PEEK?

PTFE, also known as Teflon is a versatile and cost effective material found in everyday items such as cookware pans, medical equipment, and automobile machinery. PTFE has very good thermal properties and excellent chemical inertness, especially to strong acids. The coefficient of friction is unusually low and believed to be lower than any other solids. PTFE is an outstanding electrical insulator over a wide range of temperatures and frequency.

PTFE is a thermoplastic, however, due to its high viscosity, PTFE cannot be processed using conventional polymer processing techniques. PTFE is processed by cold moulding followed by sintering (heat treatment) during which the polymer particles fuse to form a solid moulding.

PEEK is a semicrystalline thermoplastic with excellent mechanical and chemical resistance properties that are retained to high temperatures. PEEK exhibits minimal moisture uptake and is highly resistant to thermal degradation as well as attack by both organic and aqueous environments.

PEEK is however, attacked by halogens and strong acids as well as some halogenated compounds and aliphatic hydrocarbons at high temperatures. It will dissolve completely in concentrated sulfuric acid at room temperature.

PEEK can be processed by conventional methods such as injection moulding, extrusion, and compression moulding. PEEK is a much higher price polymer but provides value by offering the possibility of manufacturing parts that provide properties including lightweight, strength or toughness and the ability to withstand harsh environments for longer.

Applications requiring strength and low levels of deformation would usually exploit the properties of PEEK, whereas those requiring resistance to voltage or chemicals would be more suitable for PTFE. PTFE also rates highly in that it is self-lubricating, this makes it a preferred choice in high wear applications.