Is PEEK the Wonder Plastic?
PEEK polymer is considered one of the highest performing materials in the world. There are things being done with this thermoplastic that border on being mind-boggling! So what, exactly, is PEEK and what can it do for you?
The incredible properties of PEEK
PEEK is a semi crystalline thermoplastic known for its unique combination of properties including excellent high temperature performance, chemical and wear resistance, and biocompatibility. It has a tensile strength of 90 to 100 MPa and it melts at around 343°C (662 °F) – higher than the melting point of PTFE, PPS or Ultem(PEI)! It is highly resistant to thermal degradation as well as attack by both organic and aqueous environments. It dissolves completely in concentrated sulfuric acid at room temperature. In addition, PEEK is inherently pure, possesses great chemical resistance, and can be used in high continuous service temperature (260°C/500°F).
How does it compare to other common polymers?
PEEK is 53% harder than Acetal, has 36% greater tensile strength than nylon 6, 6 and is almost 60% stiffer! When it comes to high temperature its short term operating temperature is 300°C, 40 degrees more than PTFE – that’s 15% higher. PEEK also has excellent machinability, excellent wear and slide properties, is flame retardant, and it can protect one from nuclear blasts! (Ok, just kidding on that last one.)
On the downside there is one big disadvantage and that is the high price of PEEK – almost four times the cost of PTFE – which usually limits its application to high value items.
How is PEEK used?
Because of its robustness, PEEK is used to fabricate items used in demanding applications, including bearings, piston parts, pumps, HPLC columns, compressor plate valves, and cable insulation. It is one of the few plastics compatible with vacuum applications. It is also used extensively in the aerospace, automotive, teletronic, and chemical process industries
Leading medical device manufacturers are using PEEK in the development of many applications including spinal fusion cages, dynamic stabilization and motion preservations. In addition, PEEK is being used to create finger joints, hip and femoral bone replacements, trauma fixation plates, arthroscopic bone screws, and suture anchors. And if that were not enough advances are being made with implantable drug delivery systems, dental abutments, healing caps and implants.
PEEK is one of the only polymers that can be used as a metal replacement for high temperature applications. Initially, PEEK was considered an exotic material, but it has become an essential tool for materials engineers in applications when no other material can meet the requirements. This has been a boon for the oil and gas industry for drilling as well as production. PEEK is also a superior material for alternative energy production in the construction of solar, wind, nuclear, geothermal and hydropower equipment and components.
Flying high with PEEK components
PEEK is particularly useful in the aerospace field for its weight. In an application where two grams can make a difference and where weight is directly correlated to fuel cost, lightweight PEEK tubing is superior to stainless steel. PEEK matches aluminum in mechanical properties, and is more resistant to hydraulic fluids. Thin wall PEEK is more flexible and kink resistant than aluminum tubing. PEEK convoluted tubing is also used for its abrasion resistance properties, to protect vulnerable wires located in areas where they could be crushed or severed. All in all, PEEK’s strength, weight, and heat resistance are ideal for this application.
A welcome alternative in the operating room
PEEK can be used in the medical field as a rigid tube in minimally invasive surgery, such as stent delivery. It is also useful in medical applications because of its low coefficient of friction – which doesn’t allow heat buildup – reducing downtime and speeding up time-sensitive procedures. PEEK is ideal for medical devices which require repeated sterilization. PEEK maintains high mechanical strength, resists stress cracking, and hydrolytic stability in hot water, steam, solvents, and chemicals.
PEEK is right at home in the chemical plant
In the chemical processing industry, PEEK is chosen because it is inherently pure and has outstanding chemical resistance. Unlike most metals, such as stainless steel or aluminum, PEEK can be used in long continuous service applications with virtually no levels of contamination introduced to the chemicals being processed. Because of its excellent fatigue resistance and general mechanical properties PEEK has been shown to outperform fluoropolymers.
Is PEEK the superhero of plastics?
If you need a material that can withstand extreme temperatures and that performs incredibly well in just about every other area – and cost is not an issue – then PEEK could definitely be your “wonder” plastic!