When it comes to high-performance machining materials, PEEK (Polyether Ether Ketone) and Delrin (Polyoxymethylene, POM) are two widely used engineering plastics. Each has distinct properties, making them suitable for different industrial applications. Understanding their strengths and limitations can help engineers, manufacturers, and designers choose the best material for their specific needs.
Additionally, in advanced machining, undercut machining plays a critical role in achieving complex designs. This article will also explore undercut machining techniques, its significance, and how it is used in PEEK and Delrin machining.
What is PEEK?
PEEK (Polyether Ether Ketone) is a high-performance thermoplastic polymer known for its excellent mechanical strength, chemical resistance, and thermal stability. It is widely used in aerospace, automotive, medical, and industrial applications due to its ability to withstand extreme environments.
Properties of PEEK:
- High-temperature resistance: Can withstand temperatures up to 250°C (482°F)
- Excellent chemical resistance: Resistant to most acids, bases, and solvents
- Superior mechanical strength: High tensile strength and toughness
- Low friction and wear resistance: Suitable for high-load applications
- Good electrical insulation: Ideal for electronic and semiconductor applications
- Biocompatibility: Used in medical implants and devices
Applications of PEEK:
- Aerospace components
- Medical implants (dental and orthopedic)
- High-performance automotive parts
- Semiconductor manufacturing equipment
- Oil and gas industry components
What is Delrin?
Delrin, also known as Polyoxymethylene (POM), is an engineering thermoplastic known for its high stiffness, low friction, and excellent dimensional stability. It is widely used in precision machining due to its ease of processing and affordability.
Properties of Delrin:
- High strength and rigidity: Provides structural integrity and durability
- Low friction coefficient: Ideal for sliding and rotational applications
- Good wear resistance: Suitable for moving mechanical parts
- Dimensional stability: Maintains shape under stress and temperature variations
- Chemical resistance: Resistant to fuels, oils, and solvents (but not strong acids and bases)
- Moisture resistance: Performs well in humid environments
Applications of Delrin:
- Gears and bearings
- Bushings and rollers
- Electrical insulators
- Automotive fuel system components
- Industrial conveyor systems
PEEK vs. Delrin: A Comparative Analysis
1. Mechanical Strength
PEEK offers superior mechanical properties compared to Delrin. It has a higher tensile strength and impact resistance, making it more suitable for high-load and high-stress applications.
2. Temperature Resistance
PEEK can withstand extreme temperatures up to 250°C (482°F), whereas Delrin starts to degrade around 90°C (194°F). This makes PEEK the preferred choice for high-temperature applications.
3. Chemical Resistance
PEEK is resistant to most acids, bases, and solvents, making it ideal for harsh chemical environments. Delrin, on the other hand, is resistant to fuels and oils but can degrade in strong acids and alkalis.
4. Friction and Wear Resistance
Both PEEK and Delrin have low friction coefficients, but PEEK has superior wear resistance and can withstand higher loads, making it better for high-speed, high-load applications.
5. Biocompatibility
PEEK is biocompatible and widely used in medical applications such as implants. Delrin is not typically used in medical applications due to potential toxicity concerns.
6. Cost Considerations
PEEK is significantly more expensive than Delrin due to its high-performance properties. Delrin is more cost-effective and suitable for applications where extreme performance is not required.