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Comparing Ultem® and PEEK Plastics

COMCO Plastics, Inc. has been committed to innovation since 1956, pioneering the early use of thermosets and thermoplastics like nylon, phenolics, and Plexiglas™ in fabrication processes. Today, nearly seven decades later, we deliver reliable, precision-machined components to clients in diverse industries worldwide by utilizing high-quality plastics.

Two of our extensive material options, Ultem® and PEEK, lend their high strength and resistance capabilities to widespread component applications. Understanding these materials’ benefits and weaknesses will help you determine the ideal material for your needs.

What Is Ultem® Plastic?

Ultem® is a semi-transparent thermoplastic resin in the polyetherimide (PEI) family. This optimally processable material offers beneficial mechanical properties like high strength, elasticity, and heat and chemical resistance. Ultem withstands exposure to steam and hot water as well, allowing users to clean equipment made from Ultem with an autoclave. Compared to other thermoplastics, Ultem’s dielectric strength is among the highest. This material’s advantages and versatility give engineers ideal design flexibility with Ultem.

There are a variety of grades available, including FDA-compliant options, with enhanced characteristics to suit your needs. For example, Ultem 2300 is a popular grade for machining structural parts, reusable healthcare equipment, and electrical insulators. Ultem in the 2000 series contains a glass fiber to reinforce the material and provide tensile strength, dimensional stability, and stiffness with a good strength-to-weight ratio.

What Is PEEK Plastic?

Polyetheretherketone (PEEK) is a popular plastic polymer with an exceptionally stable chemical structure. It maintains its mechanical strength and stiffness over a broad spectrum of operating temperatures and provides excellent resistance to chemicals. PEEK is also dimensionally stable, has good CNC machinability, and resists hydrolysis when in contact with moisture.

Offering high performance and an array of beneficial proprities, PEEK is found in components throughout diverse industries because of its virtually endless application capabilities. This engineering plastic comes in various grades to deliver enhanced performance based on application-specific requirements, such as carbon fiber-reinforced PEEK for increased stiffness and high strength to bear exceedingly heavy loads and bearing-grade PEEK with a low coefficient of friction and wear rate for high-wear tasks.

Similarities Between Ultem and PEEK

Ultem and PEEK plastics lend similar benefits to an application, sharing the following characteristics:

  • Optimal strength and durability
  • Dimensional stability
  • Resistance to fatigue, stress cracking, chemicals, and hydrolysis
  • Long-term resistance to high temperatures
  • Stiffness
  • Minimal smoke production

Primary Differences Between Ultem and PEEK

While Ultem and PEEK offer similar benefits, their differences will help you decide which is suitable for your application. Consider the following differences when comparing PEEK vs. Ultem:

  • Ease of material processing. PEEK’s resistance to heat makes it both costly and challenging to process compared Ultem. That said, CNC mills can effectively machine PEEK when it’s in its solid form.
  • Resistance to high temperatures. Ultem can withstand continuous operating temperatures as high as 340º F, but PEEK resists deformation up to 500º F, with a melting point above 700º F. This makes PEEK an ideal choice for high-heat and high-load projects.
  • Resistance to chemicals. While both PEEK and Ultem offer excellent resistance to chemicals, the only substances in which PEEK will dissolve are concentrated nitric and sulphuric acids.
  • Resistance to wear. PEEK is superior to Ultem in its resistance to general wear and friction.
  • Dielectric strength. Compared to the dielectric strength of other thermoplastics, Ultem’s is among the highest.
  • Price. If budget is a concern when attempting to choose between Ultem vs. PEEK, Ultem is the better option. It shares many of PEEK’s beneficial characteristics without the significantly higher price tag, as PEEK is among the most expensive of all available polymers.

Precision Ultem and PEEK Solutions From COMCO

Ultem and PEEK are excellent choices for versatile applications, delivering heat and chemical resistance, high strength, stiffness, and chemical stability. When determining which material is ideal for your project, consider their unique features as well as your application’s requirements, environmental condition challenges, and budget.

At COMCO, we believe that you should never have to sacrifice on quality, delivery, or price. For Ultem, PEEK, and a wide assortment of other high-quality materials, we offer precision CNC machining, vacuum forming, assembly, finishing, and quality inspections to provide turnkey plastic fabrication solutions to our clients. Contact us at (718) 849-9000 to speak to a team member about our material options and plastic fabrication and machining solutions, or request a quote today to begin your project.

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