Why ULTEM® (PEI) Excels in Aerospace, Medical, and Semiconductor Applications

When designing components for the most demanding environments, engineers need materials that can perform under stress, heat, and chemical exposure — without compromising weight or reliability. Few plastics rise to that challenge like ULTEM®, the trade name for polyetherimide (PEI). With exceptional strength, thermal stability, and chemical resistance, ULTEM bridges the gap between metals and traditional polymers, offering a rare combination of performance and processability.

But even the best material needs expert handling to deliver real-world results. That’s where Pexco comes in. As one of North America’s leading custom plastics manufacturers, Pexco combines decades of polymer science expertise with advanced manufacturing capabilities — including precision extrusion, injection molding, and machining — to turn high-performance materials like ULTEM into reliable, certifiable components for critical industries.

Below, we’ll explore why ULTEM stands out for aerospace, medical, and semiconductor applications, and how Pexco’s deep technical experience helps bring its advantages to life.

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The Unique Advantages of ULTEM® (PEI)

ULTEM® is part of a class of amorphous high-performance thermoplastics known for their strength, stability, and heat resistance. It’s a material that thrives where others fail. Here’s why engineers and material scientists consistently choose it:

1. High Heat Resistance

ULTEM maintains its structural and mechanical properties at temperatures where many plastics deform. With a glass transition temperature around 217°C (422°F) and continuous-use temperature up to 170°C (338°F), it performs exceptionally well in environments where sustained heat exposure is the norm.

2. Strength and Dimensional Stability

Even under high mechanical loads, ULTEM resists creep and maintains tight tolerances. Its high tensile strength and low thermal expansion make it ideal for precision components that must retain exact geometry over time and temperature swings.

3. Flame Retardancy and Low Smoke Generation

ULTEM’s inherent flame resistance meets UL 94 V-0 ratings without additives. It also produces minimal smoke and toxic fumes, making it compliant with stringent flammability, smoke, and toxicity (FST) standards critical to air and transportation industries.

4. Excellent Electrical Insulation

PEI’s stable dielectric properties make it an excellent insulator, even at high temperatures and frequencies. That reliability supports demanding electrical and electronic applications where insulation must remain consistent under harsh conditions.

5. Chemical and Hydrolysis Resistance

ULTEM resists many chemicals, alcohols, and hydrocarbon solvents, and exhibits low moisture absorption. These properties make it suitable for wet, corrosive, or sterilization-intensive environments.

6. Biocompatibility and Sterilization Endurance

Many ULTEM grades meet ISO 10993 and USP Class VI biocompatibility requirements and can withstand repeated sterilization cycles — including steam autoclaving, ethylene oxide (EtO), and gamma radiation — without degrading.

Together, these characteristics make ULTEM an ideal candidate for industries where performance, reliability, and safety converge.

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Aerospace: Lightweight, Strong, and Flame-Safe

In aerospace, every safety standard matters. Designers face the dual challenge of minimizing weight while ensuring compliance with the strictest flame and smoke regulations. ULTEM answers that challenge by offering the mechanical integrity of metal at a fraction of the weight.

Why ULTEM Works for Aerospace

• Weight reduction without compromise: ULTEM can replace metal in brackets, housings, ducts, and interior components while maintaining stiffness and strength.
• Flame, smoke, and toxicity performance: Its inherent FST compliance supports aircraft interior and structural applications.
• Thermal endurance: It withstands extreme cabin and environmental temperature cycles.
• Electrical insulation: It performs reliably in connectors, wire harnesses, and electronic housings under heat load.

Pexco’s Role in Aerospace Component Production

Pexco brings precision and reliability to the table with advanced extrusion, injection molding, and machining processes for high-performance polymers. Its engineers understand the importance of tight tolerances, consistent surface finish, and complete material traceability in aerospace manufacturing.

Through proprietary tooling and process optimization, Pexco can extrude and machine ULTEM into custom profiles and geometries that meet stringent design and regulatory requirements. Whether a part must meet flame retardancy standards or withstand mechanical stress during flight, Pexco’s material and process control ensures consistent, certifiable quality.

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Medical: Biocompatible, Sterilizable, and Reliable

The medical field demands materials that can endure frequent sterilization, maintain dimensional integrity, and protect patient safety. ULTEM’s unique chemical and mechanical resilience makes it a top choice for reusable and high-precision medical components.

Why ULTEM Works for Medical Devices

• Biocompatible and non-toxic: Select ULTEM grades meet major medical compliance standards.
• Sterilization resistance: Components can survive steam autoclaving and EtO cycles without discoloration or property loss.
• Dimensional stability: Tight-tolerance parts maintain fit and function across multiple sterilization and use cycles.
• Chemical resistance: Resists disinfectants, alcohols, and hospital-grade cleaning agents.

How Pexco Supports Medical Manufacturing

Pexco has decades of experience in medical plastics manufacturing, including multilumen tubing, custom extrusions, and injection-molded components. The company’s engineers work closely with device OEMs to select the right ULTEM grade for each application, balancing strength, clarity, sterilization method, and regulatory requirements.

With cleanroom extrusion and molding capabilities, Pexco ensures that parts for diagnostic instruments, surgical tools, or fluid management systems meet the cleanliness and precision standards required in the medical field. Its quality systems support ISO 13485 and traceability demands, providing confidence for regulated device manufacturers.

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Semiconductor: Pure, Stable, and Chemically Resistant

Semiconductor fabrication pushes materials to their limits. Components used in wafer handling, etching, or chemical processing must maintain precision under exposure to heat, vacuum, and reactive gases — all while remaining ultra-clean. ULTEM’s performance makes it an ideal material for these conditions.

Why ULTEM Works for Semiconductor Applications

• Dimensional precision: Maintains tight tolerances critical for wafer and tool alignment.
• Low outgassing: Prevents contamination in cleanroom and vacuum environments.
• Chemical resistance: Tolerates many acids, bases, and solvents used in etching and cleaning.
• Thermal stability: Handles sustained heat exposure in high-temperature processes.

Pexco’s Capabilities in Semiconductor Manufacturing

Pexco has expanded its high-performance materials expertise into semiconductor and precision manufacturing markets, producing components that meet demanding cleanliness and dimensional standards. With state-of-the-art extrusion and machining capabilities, Pexco delivers custom ULTEM parts such as fluid management fittings, insulators, and structural supports that perform under chemical and thermal stress.

For semiconductor clients, Pexco emphasizes material purity, process control, and surface finish, ensuring parts meet the contamination standards required for cleanroom and vacuum environments.

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From Material to Market: Pexco’s End-to-End Advantage

Selecting a high-performance resin like ULTEM is only the first step — processing it correctly is what turns potential into performance. Pexco’s integrated approach provides customers with a complete path from design concept to production part, all under one roof.

Pexco’s Key Capabilities Include:

• Material selection and formulation support: Engineers help identify the right ULTEM grade (or blend) for a project’s thermal, mechanical, or regulatory requirements.
• Precision extrusion: Custom profiles, rods, and tubes manufactured to exact dimensional tolerances.
• Injection molding: For high-volume or complex geometries, Pexco molds ULTEM with attention to surface finish, shrink rate, and tooling optimization.
• CNC machining: Multi-axis machining delivers tight tolerances for prototype or production parts from ULTEM stock.
• Value-added finishing: Services such as annealing, polishing, and post-machining treatments improve performance and stability.
• Quality and traceability: Pexco’s manufacturing processes support rigorous documentation, inspection, and traceability protocols to meet the expectations of regulated industries.

By combining these technical strengths, Pexco helps manufacturers in aerospace, medical, and semiconductor sectors confidently integrate ULTEM into mission-critical products.

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The Power of ULTEM, Realized Through Expertise

ULTEM® is more than just another engineering plastic — it’s a material built for environments where precision, performance, and safety are non-negotiable. Its strength, heat resistance, chemical durability, and electrical insulation properties make it invaluable in aerospace, medical, and semiconductor applications.

But unlocking those properties requires a partner who understands both the science of materials and the art of manufacturing. Pexco’s long-standing expertise in processing high-performance thermoplastics, its commitment to quality and traceability, and its versatile manufacturing capabilities make it a trusted resource for companies that depend on precision-engineered plastic components.

Whether it’s a sterilizable medical device, a flame-safe aircraft interior part, or a precision semiconductor fixture, Pexco’s expertise with ULTEM ensures performance where it matters most — in the air, in the body, or in the cleanroom.