CNC machined PEEK part

Polyetheretherketone (PEEK) is a thermoplastic polymer used in a wide range of applications in the medical, automotive, chemical and energy industries. This article describes five basic tips for processing PEEK plastics, including annealing, using carbide and polycrystalline molds, using the right coolant, using the right machining parameters, and avoiding contamination. These tips will help you finish your PEEK products correctly.

Polyetheretherketone (also known as PEEK) is a popular thermoplastic polymer used in a wide range of applications in the medical, automotive, chemical and energy industries. However, given that PEEK is one of the most commonly used plastics in CNC part design, you might think that no one would ever make the mistake of making low-quality and unusable PEEK parts. But you'd be wrong: there's more to PEEK machining than meets the eye. For example, PEEK has poor heat dissipation properties, making it susceptible to heat-related cracking during cutting operations. In addition, PEEK requires special tools and coolants, especially when manufactured for the medical industry.

Five Basic Tips for Processing PEEK Plastic. two common grades of PEEK, There are two common grades of PEEK:

1. Industrial Grade PEEK is a strong, wear-resistant thermoplastic with a low coefficient of friction and high impact strength. Components made from industrial grade PEEK are used in the aerospace, automotive, chemical, electronics and energy industries. Some industrial grade PEEK plastics are reinforced with carbon fiber, which provides higher strength and wear resistance than traditional PEEK plastics.

Medical grade PEEK has all the mechanical properties of industrial grade PEEK. However, in addition to all of these properties, medical grade PEEK plastics are also chemically resistant and biocompatible ㅡ meaning they have no harmful effects on the human body. This makes them particularly useful in customized medical implants, such as joints.

PEEK 5 processing techniques

1. Annealing PEEK plastic before processing

PEEK plastic is usually used in various sizes of rods, sheets or injection molded blanks. But before you start machining these parts, you must remove the accumulated stresses by annealing ㅡ This is a heat treatment process that involves heating the plastic to a predetermined temperature, holding it for a certain period of time, and then cooling it to room temperature.

Annealing improves the crystallinity of the PEEK part and reduces internal stresses, thereby preventing the possibility of surface cracking during CNC cutting operations. One thing to keep in mind, however: if you plan to process PEEK parts for extended periods of time, you may need to perform an additional annealing process.

2. Using Carbide and Polycrystalline Molds

All PEEK grades are abrasive to cutting tools ㅡ This means that they can cause damage, wear or removal of tool material during the cutting operation. For this reason, we recommend that you use carbide tools for small batch machining of common PEEK grades. However, for PEEK grades reinforced with glass and carbon fiber, you may want to consider using polycrystalline (PCD) tooling, especially for long manufacturing runs.

3. Use the right coolant

Although PEEK melts at very high temperatures, it still needs to be cooled sufficiently during processing to prevent distortion and cracking. Standard liquid coolants (petroleum-based) are ideal when cutting industrial-grade PEEK plastics. However, for medical grade PEEK, you want to avoid standard liquid coolants at all costs.

This is because standard liquid coolants can affect the biocompatibility of medical grade PEEK, making it unsuitable for manufacturing medical parts. We recommend that you use compressed air or purified water to cool your medical grade PEEK plastic.

4. Use the Right Processing Parameters

In order to experience seamless manufacturing of PEEK parts, you need to ensure that the implementation of drilling, milling and turning operations using the correct machining parameters according to the ideal range of cutting speeds and feed rates listed in the manufacture of PEEK parts.

5 Avoiding Contamination

Contamination is a serious issue when machining medical-grade PEEK plastics because it affects their biocompatibility. Therefore, use protective gloves when handling PEEK parts. In addition, you will want to store processed medical grade PEEK parts in airtight containers to prevent contamination.