Author: Prof.Dr.Brando Okolo
PEEK (Polyetheretherketone) is a semi-crystalline thermoplastic polymeric material. Its introduction into the market as an industrial material has revolutionized materials choice by engineers serving across a wide range of sectors.
Here are some attributes of PEEK giving perspective on its application areas:
- Thermal stability up to 250°C (it does not suffer structural deformation hence can be used in water boilers or low pressure steam systems without change in its physical properties; its melting temperature is 343°C.)
- Good wear and abrasion properties (can be used in bearing, sliding surfaces and systems where surfaces in relative motion must maintain dimensional tolerances) - better than titanium and steel.
- Good creep properties (can be loaded under static loading conditions for a long time without permanent deformation).
- Very low moisture absorption.
- Repeatedly sterilize-able using steam (hence eliminating and/or preventing the survival of germs, bacteria and other microorganisms).
- Bioinert/biocompatible with flexural moduli similar to that of human bone than any other implant material hence less stress shielding and better bone resorption.
- Chemically inert therefore can be used in harsh corrosive operating fields providing attendant saving on anti-corrosion treatment.
- It has a density that is at least 5 times less than more technical metals but capable of withstanding mechanical loads inherent in most engineering operations.
- Good electrical insulation.
- Holds a V-0 flammability rating (that means it stops burning within 10 seconds once inflamed and drips hot particles which are not inflamed).
- PEEK is approved by the FDA for food and contact applications.
Some established application areas of PEEK:
- Clamps and brackets for structural parts.
- Laser printer parts where heat resistance, high strength, wear and torque resistance (gears and bushings) are required.
- Seals and gaskets in oil and gas applications due to its stability at relatively high temperatures, resistance to corrosive influences, stability at pressures up to 200 MPa and attendant gains in component lifetime under wear and pressure loading conditions.
- For implant in orthopedics as support structures in bone fracture, cages and rods for spinal implant.
- For prosthetics in dentistry as crowns and bridges inserted as dental discs.
- For gear systems where they are known to produce up 50% reduction in noise, vibration and hardness (NVH).
- Parts for vacuum pumps due to their low wear, dampening and chemical inertness.
Light weight engineering:
- No lubration under tribological loading conditions as in bearing systems.
- About one-fourth lower moment of inertia compared to metallic structural materials.
- Has up to twice the operating lifetime compared to steel based bushings.
We now have a light weight (about 70% lighter than most technical metals) material capable of replacing metals in some key engineering applications because its thermo-mechanical properties are applications competitive. Implementing such a material in industry could result in huge financial amount of savings in energy and reduction in carbon footprints.
- This material is expensive compared to Aluminum and other technical polymers though its economic benefit as an engineering material outweighs its entity price. Most PEEK materials used in the industry are processed using injection moulding or machined (drilling, milling, cutting) using computer numerical control (CNC) methods. These processing methods are accompanied by unavoidable material waste generation. Waste (even recycle-able waste) is bad economics for any industry.
- If PEEK could be processed using 3D Printing technologies the following will happen: (i) no waste generation, (ii) ability to mass customize the part - e.g. patient-specific implants in the medical sector (iii) low investment on machine and operatpr training making it easy for small and big businesses to benefit.
- The most affordable 3D printing technology - FFF Technology- can now be used for PEEK.
- Indmatec GmbH, located in Karlsruhe Germany, extruded raw PEEK into a high quality filament form and has proven the technical possibility of 3D printing PEEK using FFF technology. They also offer the technical support tp help you 3D print any technical thermoplastic material you wish to have in your products.