PEI CNC Machining Service

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PEI in CNC Machining

Polyetherimide (PEI), known commercially as Ultem, is a high-performance thermoplastic renowned for its exceptional mechanical, thermal, and electrical properties. PEI exhibits high strength and rigidity, excellent dimensional stability, and outstanding resistance to high temperatures and harsh chemicals. These unique properties make PEI ideal for various CNC machining applications across multiple industries.

Price:$$
Available PEI at RapidDirect:PEI Amber (ULTEM1000), PEI Black (ULTEM1000)
Lead Time:< 10 days
Wall Thickness:Minimum of 0.5 mm
Tolerances:±0.005″ (±0.125mm)
Max Part Size:1200 x 500 x 150 mm
Applications:Medical device components, electrical insulators, aerospace parts, and automotive components

Machined PEI Properties

Ideal for demanding applications, PEI offers a combination of durability and precision. Learn more about the properties of PEI that make it a popular choice in CNC machining.

Tensile Strength, Yield (MPa)Elongation at Break (%)Hardness (Rockwell R)Heat Deflection Temperature (°C)Density (g/cm³)
110201202001.27
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Surface Finishing Options for PEI

RapidDirect offers a range of surface finishing options to enhance the performance and appearance of your CNC machined PEI parts. Our extensive finishing services ensure that your parts meet all functional and aesthetic requirements.

As machined  
PEI parts often come off CNC machines with a smooth, naturally finished surface, which is functional and visually appealing for many applications without further finishing.
Sand Blasting
This works well to achieve a matte, slightly textured surface on PEI, although it may reduce material strength slightly if overdone.
Tumbling
This works well to achieve a matte, slightly textured surface on PEI, although it may reduce material strength slightly if overdone.
Heat Treatment
PEI naturally withstands high temperatures, so heat treatment might not alter its properties significantly. Instead, it’s primarily used for stress-relieving if needed.
Teflon Coating
Adding a Teflon layer is possible and can provide PEI with enhanced non-stick and low-friction properties, ideal for parts involved in sliding or wear-heavy applications.
Painting
Painting PEI is an excellent option, especially for aesthetic or branding purposes. Proper surface prep ensures paint adherence and durability.

Pros and Cons of
PEI CNC Machining

PEI CNC machining provides several distinct advantages, but some considerations must be made for optimal application.

Pros

  • High Strength and Rigidity: PEI offers excellent mechanical properties, maintaining its strength and rigidity under various conditions, making it suitable for load-bearing applications.
  • Thermal Stability: With a high heat deflection temperature, PEI parts can withstand continuous use at elevated temperatures without losing their structural integrity.
  • Chemical Resistance: PEI is highly resistant to a wide range of chemicals, solvents, and disinfectants, making it ideal for applications in harsh environments.
  • Dimensional Stability: The material’s low thermal expansion coefficient ensures that PEI parts maintain their shape and dimensions over a wide temperature range.
  • Electrical Insulation: PEI’s excellent electrical insulating properties make it a preferred choice for electrical and electronic components.

Cons

  • Cost: PEI is more expensive than many other engineering plastics, which can increase the overall cost of parts and projects.
  • Machining Difficulty: The hardness and rigidity of PEI can make it challenging to machine, requiring specialized tools and expertise to achieve precision results.
  • Limited Color Options: PEI is primarily available in amber and black, which may not meet the aesthetic requirements of all applications.

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FAQs

Machining PEI requires specialized tooling due to its high strength and rigidity. Carbide or diamond-coated tools are recommended to handle the material effectively. Additionally, maintaining sharp cutting tools and using appropriate cooling methods are crucial to achieve precise results and extend tool life.

The typical lead time for CNC machining PEI parts is around one week. This timeframe can vary depending on the complexity of the part, the volume of the order, and any additional finishing requirements. At RapidDirect, we strive to provide accurate lead times and efficient production schedules to meet your project deadlines.

When procuring PEI for CNC machining, it is important to consider the material grade and its intended application. Ensure that the PEI grade selected meets the specific mechanical, thermal, and chemical requirements of your project. Additionally, work with a reputable supplier to obtain high-quality PEI material and verify its certification to meet industry standards. Proper storage and handling of PEI are also essential to prevent contamination and maintain its properties before machining.

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