PEEK

Discover the Exceptional Properties of PEEK - A High-Performance Thermoplastic Polymer

About PEEK

PEEK (Polyether Ether Ketone) is a high-performance thermoplastic polymer that is known for its exceptional mechanical, thermal, and chemical properties. Here are some of the key properties of PEEK:

High Resistance at High Temperatures: PEEK has excellent thermal stability and can withstand high temperatures up to 260°C (500°F) without losing its mechanical properties. This property makes it a suitable material for high-temperature applications in industries such as aerospace, automotive, and electronics.
Biocompatibility: PEEK is a biocompatible material that is commonly used in medical and dental applications such as implantable devices, orthopedic implants, and dental implants. Its biocompatibility is due to its inertness and resistance to degradation in the human body.
Resistance to Ultra-High Vacuum: PEEK is also known for its high resistance to ultra-high vacuum environments. Its low outgassing rate makes it a suitable material for use in space and vacuum applications, where contamination is a concern.
Exceptional Chemical Resistance: PEEK has excellent resistance to a wide range of chemicals, including acids, bases, solvents, and fuels. Its chemical resistance makes it a suitable material for use in harsh chemical environments, such as chemical processing and oil and gas industries.
High Strength and Stiffness: PEEK has a high strength-to-weight ratio, making it stronger and stiffer than many other thermoplastics. This property makes it a suitable material for high-stress applications, such as aerospace and automotive parts.
Excellent Electrical Properties: PEEK has excellent electrical properties, including high dielectric strength, low dielectric constant, and low dissipation factor. These properties make it a suitable material for electrical and electronics applications, such as connectors and insulators.

Subtypes

Generic PEEK

The versatility of PEEK can be used to machine it for many purposes. PEEK is very similar to other engineering plastics. Its heat resistance is one of its greatest strengths. It can withstand high temperatures longer than other plastics. PEEK is also hydrophobic so it doesn’t readily absorb water and outgasses little in vacuum conditions. This stability is a huge asset. PEEK can be used for medical purposes, including temporary implants. It can also be used to make aerospace components that are exposed to extreme vacuum.

Surface Finishes

As Machined Surface Finish

As machined surface finish is the most basic surface finish available for PEEK parts. This surface finish is achieved by leaving the part as it is after CNC machining. This type of finish can vary depending on the machining process used, but typically, it is characterized by visible tool marks and surface roughness. As machined surface finish is the most economical option and is suitable for many applications where surface aesthetics are not critical.

Benefits of As Machined Surface Finish

Cost-effective: As machined surface finish is the most economical option, as it does not require any additional treatment or finishing process, which can add to the overall cost.
Quick Turnaround: As machined surface finish can be achieved quickly and easily during the machining process itself, making it a time-efficient option for parts that need to be produced quickly.
Retains Original Surface Properties: As machined surface finish retains the original properties of the PEEK material, including its strength, stiffness, and chemical resistance.
Allows for Secondary Treatments: As machined surface finish provides a suitable base for secondary treatments such as painting, coating, or plating, making it a versatile option for parts that require additional treatment.
Provides Good Lubricity: As machined surface finish can provide good lubricity, making it suitable for parts that require low friction or wear resistance.

Bead Blaster Surface Finish Bead

Blasting is a surface treatment process that uses small glass beads or other abrasive media to blast the surface of a PEEK part. This process can be used to remove any visible tool marks and improve the surface finish of the part. Bead blasting is an effective way to achieve a uniform and aesthetically pleasing surface finish on PEEK parts. This type of finish is particularly useful for parts that will be visible or in contact with sensitive surfaces.

Benefits of Bead Blaster Surface Finish

Bead blasting provides a number of benefits for PEEK parts. First, it can be used to create a uniform surface finish, which is particularly important for parts that will be visible or in contact with sensitive surfaces. Second, bead blasting can help remove any surface imperfections or tool marks, improving the part’s overall quality. Finally, bead blasting can be used to add texture to the surface of the part, which can improve its grip or adhesion to other surfaces.

Design Tips

PEEK is a versatile material that can be machined to create complex and precise parts. When designing your PEEK part, here are some tips to keep in mind:

Wall Thickness: PEEK has a high thermal expansion coefficient, which means that it will expand and contract with changes in temperature. To avoid warping or distortion, it is essential to design parts with consistent wall thickness. Thinner walls will cool faster and may warp, while thicker walls may not cool evenly, leading to internal stress.
Radii and Fillets: PEEK has a high stiffness and hardness, which can make it prone to stress concentration and cracking. To reduce stress concentration, it is essential to design radii and fillets in sharp corners and edges. This design feature can improve the part’s strength and durability.
Undercuts: PEEK is a rigid material that does not easily deform. It can be challenging to remove parts with undercuts, such as threads or keyways. To make it easier to remove these parts, it is essential to design undercuts with draft angles and consider adding relief cuts.
Orientation: PEEK has anisotropic properties, meaning that it exhibits different mechanical properties in different directions. When designing a part, it is important to consider the orientation of the part with respect to the direction of applied loads. The orientation of the part can significantly affect its mechanical properties.
Tool Selection: PEEK is a hard and abrasive material that can wear down cutting tools quickly. It is important to select the appropriate cutting tools and machining parameters to avoid tool wear and ensure dimensional accuracy and surface finish.

Designing parts from PEEK requires careful consideration of the material’s properties and behavior during machining. Keeping these design tips in mind can help ensure that your PEEK parts are machined to the desired dimensions, tolerances, and surface finish.

FAQ

What are the tolerances of PEEK machining?

The tolerances of PEEK machining depend on various factors such as the complexity of the part, the size of the part, and the machining process used. Generally, the achievable tolerances for PEEK machining range from ±0.001 inches to ±0.005 inches, depending on the specific machining process and the machinist’s skill.

What material is similar to PEEK?

Materials that are similar to PEEK in terms of their properties include Polyphenylene Sulfide (PPS), Polyetherimide (PEI), and Polyamide-Imide (PAI). These materials offer similar mechanical, thermal, and chemical properties as PEEK and are used in similar applications.

How to machine PEEK plastics?

PEEK can be machined using conventional machining techniques such as turning, milling, drilling, and grinding. However, due to its high strength and hardness, it is essential to use sharp cutting tools and appropriate machining parameters to ensure dimensional accuracy and surface finish. It is also recommended to use coolant during machining to reduce heat buildup and prevent deformation of the part.

How thin can you machine PEEK?

The minimum thickness that can be machined in PEEK depends on the specific machining process used and the machinist’s skill. Generally, the thinnest sections that can be machined in PEEK range from 0.010 inches to 0.020 inches. However, thinner sections may be machinable with specialized techniques such as wire EDM or laser cutting.

What are the disadvantages of PEEK?

While PEEK offers exceptional properties, it also has some disadvantages. One of the main drawbacks of PEEK is its high cost compared to other thermoplastics. PEEK is also prone to stress cracking under certain conditions, which can affect its durability. Additionally, PEEK can be challenging to bond or join using adhesives due to its chemical resistance.

Is PEEK plastic toxic?

No, PEEK is not toxic. It is a biocompatible material that is commonly used in medical and dental applications, including implantable devices, orthopedic implants, and dental implants. PEEK is also approved by regulatory bodies such as the FDA for use in medical devices. However, it is important to handle PEEK with care during machining to avoid inhaling dust or particles, which can cause respiratory irritation.