You don’t choose PEI because it’s “better” than other plastics in every way, but because it offers a unique combination that few other materials can match: heat resistance, flame retardancy, and electrical insulation, all in a single component. At ANKRO, we machine PEI and work with you to determine whether it’s the right choice for your application.
PEI remains usable continuously up to approximately 170°C and truly retains its shape and strength up to a much higher temperature, around 217°C. Above that threshold, the material softens. This is a significantly wider range than that offered by engineering plastics, which reach their limits at much lower temperatures.
The material is flame-retardant and produces little smoke when exposed to fire. This property is inherent to the material itself. PEI is also an excellent electrical insulator, even at higher temperatures, and retains its dimensions well: it exhibits virtually no creep under prolonged stress and expands very little in response to temperature fluctuations.
Compared to, for example, PEEK—another high-performance plastic that we machine at ANKRO—PEI has a lower operating temperature.
PEI is an amber-colored to transparent plastic that machines well when turned and milled. However, the material is prone to chipping or cracking at sharp inside corners, so when turning and milling PEI, we opt for rounded transitions instead of sharp corners. We also adjust the tools and speed to minimize burr formation. For small holes or narrow grooves, we work more carefully to ensure precision.
Individual prototypes can often still be produced successfully using standard settings. With larger production runs, however, even minor deviations become more noticeable: a cutting angle that’s just off, or a conditioning step that’s skipped, leads to a noticeably higher scrap rate when producing a hundred units than it would for a single part.
In serial plastic processing, we build that control into the process itself, rather than measuring afterward to see if it went well. That is exactly where ANKRO sets itself apart: not just getting that one tricky PEI part right, but maintaining that same quality across an entire production run.
PEI is used in the following industries or applications:
If a component operates at moderate temperatures without any electrical insulation requirements, PEI is a relatively expensive choice. POM, PA6, and similar materials will provide the same results in such cases. These are our engineering plastics.
If the application requires heat resistance up to 170°C combined with flame retardancy and electrical insulation, without involving heavy chemical exposure, then PEI is often the more cost-effective choice.
If, on the other hand, the part must withstand aggressive chemicals or prolonged mechanical stress at higher temperatures, then PEEK is the better choice.
At ANKRO, we work with you to make that assessment, even if the concept or drawing is already largely finalized. We recommend the material that is technically suitable and keeps the unit price realistic for mass production. View all the plastics we machine at ANKRO.
Please feel free to contact us. You can do so by phone at +31 (0)183 304 872 or by filling out the contact form. We will handle your question as soon as possible.
