PEEK (Polyetheretherketone)

PEEK (polyetheretherketone), as a member of the specialty engineering plastics, is widely used in industrial production due to its lightweight, high strength, wear resistance, corrosion resistance, and high temperature resistance. Furthermore, its excellent biocompatibility and elastic modulus similar to human bone have earned it the reputation of being the next generation of ideal orthopedic implant material after titanium alloys.

 

PEEK fatigue properties

The phenomenon that materials, parts and components suffer local damage at a certain point or several points under cyclic loading, and form cracks or allow cracks to propagate further until complete fracture after a certain number of cycles. Fatigue performance refers to the ability of a material to resist fatigue failure [1].

Today, we’ll discuss the fatigue characteristics of PEEK. Using the YY/T 1503 (ASTM F382) test standard, we conducted bending fatigue tests on AKSOPEEK® LCF bone plates (4mm thick) under a load of 800N, a frequency of 5Hz, and 1.2 million cycles. The performance was comparable to titanium alloys and superior to pure titanium.
To further compare the fatigue strength of AKSOPEEK® LCF and titanium alloys, we selected four sets of 2mm thick titanium alloy (Ti-6Aal-4V) and AKSOPEEK® LCF specimens for fatigue testing under 382N conditions. All four sets of AKSOPEEK® LCF specimens showed no failure after 1 million fatigue cycles, while the titanium alloys failed due to fatigue at 73,000, 82,000, 79,000, and 92,000 cycles, respectively.

Using the YY/T 0959 (ASTM F2077) testing standard, the AKSOPEEK® Natural interbody fusion cage (H = 6.3 mm) was subjected to compressive fatigue testing at a load of 2000/4000 N, a frequency of 5 Hz, and a test cycle of 5 million cycles. No fatigue failure was observed. Static tests before and after fatigue also showed no decrease in strength, and this type of fusion cage only exhibits compressive yielding at 12000 N.

Deeply rooted in sports medicine

The company has established a dedicated team to work with clients in the medical industry to be responsible for the research, development, production and sales of medical polymer materials and products such as medical PEEK, PPSU, and LCF/PEEK thermoplastic composites.

In 2021, to meet the development needs of sports medicine in China, the company actively cooperated with major medical institutions across the country to develop sports medicine molds, which have the following advantages:

(1) Many years of experience in PEEK injection molding;

(2) A well-established sports medicine development process;

(3) Seamless switching between the same brand and model of micro injection molding machine and that of competitors;

(4) Its comprehensive after-sales service system has been recognized by major medical institutions in China.

Based on the present and looking to the future, the implantable PEEK project was officially launched in 2021 and is currently in the second round of testing. The test results are expected to be released around August 2022. In order to better standardize implantable PEEK, a new series of implantable AKSOPEEK grades have been added.

1) AKSOPEEK® Natural: Implant-grade pure PEEK;

2) AKSOPEEK® HA: Hydroxyapatite enhances biocompatibility in implantable PEEK materials;

3) AKSOPEEK® CF: Short-cut carbon fiber implant-grade PEEK material;

4) AKSOPEEK® LCF: Continuous carbon fiber implant-grade PEEK material;

 

Note: [1]. Fatigue, Baidu Encyclopedia.