Complete Guide to PEEK: Properties and Technical Applications

What is PEEK?

PEEK (polyether ether ketone) is an organic thermoplastic polymer belonging to the family of polyetherketones, often referred to as the king of polymers, thanks to a fantastic mix of very high mechanical, thermal and chemical properties.

What are the properties of PEEK?

It has a tensile strength with values ​​approaching 100 MPa, as some non-ferrous alloys but with a low density of 1.30 g / cm ^ 3 against 2.8 g / cm ^ 3 of light aluminium alloys. The combination of high mechanical strength and low density make it a formidable candidate to replace metal alloys, while allowing the creation of complex geometries thanks to the versatility of additive manufacturing.

How is PEEK processed?

In fact, PEEK, although difficult to process, is suitable for FDM additive manufacturing. The printer requires very high working temperatures of over 400 ° C for the nozzle and at least 70 ° C in the heated chamber; this temperature are not reachable by consumer machines. Furthermore, this technology, implemented in industrial printers, allows to create supports easily removable material at the end of the construction process. This feature eliminates the design constraints dictated by undercuts, internal channels and complex geometries.

What are the states of PEEK?

PEEK can have two different crystalline states:

• amorphous - recognizable by the amber colour is characterized by the chains that form it arranged in an unordered way. It differs in greater ductility and impact resistance, but with a lower maximum operating temperature.
  
  
  
  
  

• semi-crystalline - recognizable by its characteristic skin colour it has slightly better mechanical and chemical properties but exhibits a more brittle behaviour. It is the ideal state for applications at very high temperatures as it can withstand temperatures of use up to 250°C.

What is PEEK used for?

This interesting polymer is used in various fields in which the components are used in harsh conditions and in difficult environments, such as aerospace for the manufacture of structural components, covers, insulations or in the medical field as it is considered advanced biomaterial, in implants and prostheses.