High-performance polymers (HPP) have been used in industry for several decades, particularly in injection molding and machining. However, in recent years, they have ceased to be materials exclusive to traditional engineering and have made their appearance in additive manufacturing. This type of polymer is characterized by properties superior to those of conventional polymers. We are talking here about greater strength, better wear resistance, and greater durability. Among the HPPs most commonly used in additive processes are the polyaryletherketone (PAEK) family, which includes PEEK and PEKK, and polyetherimide (PEI), better known by its trade name, ULTEM.
The processing of HPPs in 3D printing continues to be refined, but their role is increasingly important in solving real-world problems in increasingly complex value chains, with shorter lead times and optimized costs. Here, we explore eight reasons to choose high-performance polymers in additive manufacturing. The goal is to understand why these materials can move beyond being an experimental alternative to becoming an advanced manufacturing resource.
3D-printed parts in PEEK. (Photo Credit: Elecrow)
#1: Good Thermal Resistance
One of the most remarkable features of high-performance polymers is their thermal stability under extreme conditions. While standard plastics like ABS start to lose their mechanical properties at around 90–100 °C, materials such as PEEK maintain their structure during continuous use up to 250 °C and can withstand temperature spikes up to 300 °C. PEKK and PEI behave similarly, with heat deflection temperatures above 200 °C, making them a strong choice for applications where thermal stability is essential. This level of performance allows these polymers to be used in harsh industrial environments, including parts located near engines in automotive applications or structural supports in aerospace turbines.
Their performance can also be seen in motorsports. NASCAR has used 3D printing with ULTEM™ 9085 to produce a NACA duct installed on the engine’s lower panel, designed to channel and expel hot air generated during competition.
#2: Chemical Resistance
Chemical resistance is another factor that sets high-performance polymers apart. Some polymers degrade rapidly when exposed to organic solvents, hydrocarbons, or industrial fluids, but this is not the case for HPPs. They maintain their structure and functionality almost unchanged in environments where most thermoplastics would fail. As a result, they are well-suited for applications in chemical engineering, fluid transport systems, and medical equipment that undergo chemical disinfection or sterilization.
#3: Strong Mechanical Properties
High-performance polymers stand out for their balance of strength, stiffness, and toughness, which explains their use in functional parts subjected to prolonged stress. Unlike standard thermoplastics, high-performance thermoplastics offer mechanical properties that can rival those of lightweight metals like aluminum, with the added advantage of low density. For example, PEEK can reach a tensile strength of 90 to 100 MPa, higher than that of PLA, which is around 60 MPa. Its fatigue resistance is closely tied to its mechanical properties, allowing HPPs to maintain performance over many cycles, even under dynamic conditions and temperature changes. They are also impact-resistant, so a component made of PEKK, for instance, can absorb sudden loads without cracking. It’s worth noting that most HPPs require post-processing, such as annealing or HIP treatment, to relieve residual stresses, improve layer cohesion, and maximize material density in order to achieve these mechanical properties.
A PEKK part before and after the annealing step.
#4: Metal Replacement
One of the most transformative trends in additive manufacturing is the use of high-performance polymers to replace metal components. These materials are appealing due to their combination of high chemical resistance, thermal stability, mechanical strength, and reduced weight compared to equivalent metal parts. While 3D printing with HPPs still presents challenges, processing these materials offers significant advantages. Consider the large amounts of waste generated by metal machining and the high cost of tooling, which still often cannot produce complex geometries or internal channels. Another key factor is the corrosion resistance of high-performance polymers, a common weakness for metals.
It is important to note that although high-performance polymers can offer mechanical properties comparable to metals, most are processed via FDM/FFF. This means that parts may exhibit some anisotropy depending on layer adhesion and print orientation. This factor must be considered when designing components for critical loads, but it does not limit their use.
#5: Medical Compatibility
Of all the applications of high-performance polymers, the medical field has perhaps benefited the most from their unique properties. In particular, PEEK is recognized for its biocompatibility, meaning it is safe for prolonged contact with the human body. With a strength similar to that of human bone, PEEK is used to produce custom implants that reduce postoperative complications and integrate seamlessly with surrounding tissue. 3D printing of PEEK in healthcare is gradually gaining ground, with procedures continuing to be refined. One notable example is 3D Systems, which last year received FDA approval for the world’s first 3D-printed VSP PEEK cranial implant. These implants can even be produced directly in hospitals using sterile equipment.
A PEEK cranial implant. (Photo Credit: Xilloc Medical)
#6: Reinforcement Capability
HPPs can also be reinforced with fibers, further enhancing their properties. This versatility makes them highly adaptable to a range of industrial environments, from aerospace to defense. Combining reinforcement with additive manufacturing also enables advanced design strategies, such as aligning fibers along load directions to optimize the part’s mechanical performance.
#7: Design Freedom for Critical Applications
The true value of high-performance polymers in 3D printing lies in their ability to enable critical applications, where material failure could have serious consequences for safety, cost, or operational continuity. Through 3D printing, HPPs meet performance requirements while allowing geometries and designs that would be impossible to achieve with traditional manufacturing methods for these polymers. They are especially valued for developing applications in the aerospace, automotive, and rail sectors.
This adoption is further supported by the fact that many of these materials hold international certifications, ensuring their reliability in demanding environments. For example, ULTEM™ 9085 meets FAR 25.853 standards for flammability, smoke, and toxicity (FST) in aircraft interiors, as required by the Federal Aviation Administration and the European Aviation Safety Agency. Similarly, the FDA and ASTM approve the use of PEEK in implantable and surgical devices.
A 3D printed aircraft interior part made from ULTEM. (Photo Credit: Roboze)
# 8: Balance of Weight and Performance
Finally, high-performance polymers offer an optimal balance between lightness and technical performance. Unlike metals, which are strong but have high density, HPPs can provide comparable properties in many cases while reducing weight by up to 70 percent compared to equivalent parts made from lightweight alloys such as aluminum. In the aerospace industry, this advantage is critical, as cutting just one kilogram from an aircraft’s weight can save thousands of liters of fuel over its lifetime.
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*Cover Photo Credit: VESTAKEEP