What Is PEKK and Why Is It Used for Industrial 3D Printing?
Polyetherketoneketone, or PEKK, is a high-performance engineering thermoplastic known for high-temperature capability and chemical resistance. The material is also used in applications where flame, smoke, and toxicity characteristics are important. The transcript identifies a UL 94 V-0 FST-related rating and notes the material’s use in aerospace applications.
PEKK belongs to the PAEK family of high-performance polymers and can be processed in both amorphous and semi-crystalline states. That distinction matters when selecting a material and developing a reliable FFF process.
For this application, PEKK-A is particularly interesting because its amorphous formulation can be printed more readily than highly crystalline PEKK formulations that may present processing problems.
Why PEKK-A Can Be Easier to Print Than Highly Crystalline PEKK
Not all PEKK behaves the same way during extrusion. A highly crystalline PEKK formulation can create significant problems inside the hot end. In the process described here, a more crystalline PEKK material produced repeated jams and clogs in the heat break, making it impractical to print reliably.
PEKK-A takes a different approach. Although it can still be crystallized during processing, its amorphous nature makes the extrusion process considerably more manageable. With an established material profile, the process becomes close to a plug-and-play workflow.
This is an important distinction for engineers evaluating high-temperature 3D printing. Material selection is not simply about choosing a polymer with the required mechanical or thermal properties. The polymer must also be compatible with the complete extrusion and thermal-management system.
Preparing a PEKK-A Print in PrusaSlicer
The workflow begins in PrusaSlicer with a high-temperature profile for the 22 IDEX. The system includes predefined profiles for multiple material categories, including high-temperature materials and PEKK-A.
For the example part, the process uses a high-temperature extrusion profile with the nozzle operating in the roughly 380 to 400 °C range. The build plate is configured around 180 °C, while the active chamber is maintained at approximately 100 °C.
Preconfigured material profiles significantly reduce the amount of trial and error involved in printing high-performance polymers. Geometry, wall thickness, size, and other application-specific variables can still require adjustments, but a validated starting profile gives the operator a much better baseline.
DFAM Matters Before You Even Start Slicing
One of the easiest ways to make high-temperature 3D printing more difficult is to begin with a part designed entirely around another manufacturing process.
Design for Additive Manufacturing, or DFAM, should be considered before the part reaches the slicer. Components originally designed for injection molding or CNC machining may contain features that create unnecessary overhangs, supports, thermal mass, or other printing challenges.
A relatively simple bracket can demonstrate the advantage of good DFAM. The example part has straightforward geometry, requires no support material, and produces a clean toolpath with minimal complications.
A small design change can sometimes make an important difference. For example, adding a 45-degree chamfer to the bottom edge of the bracket could make part removal easier while maintaining the functional geometry.
Watch Thermal Mass When Printing High-Temperature Polymers
High-temperature materials introduce another consideration that is easy to overlook: thermal mass.
The example bracket contains an area with approximately ten perimeter lines. While that does not necessarily make the part unprintable, the additional material concentration could produce localized thermal effects. Extra thermal mass can contribute to excessive heat retention and potentially result in a softer or more distorted region.
This is one reason why inspecting the sliced toolpath is valuable before committing expensive engineering filament to a long print. Looking at the actual G-code path can reveal unexpected wall concentrations, infill transitions, or other features that are difficult to recognize from the solid model alone.
How Much Does a PEKK-A Print Cost?
High-performance polymers can make material cost a significant part of the economics of additive manufacturing.
For the example print, the PEKK-A filament cost is approximately $595 per kilogram. The sliced part requires about 56 grams of material, producing a calculated material cost of approximately $33.56.
The estimated print time is approximately 2 hours and 6 minutes, including roughly seven minutes for the first layer.
These numbers illustrate why process control matters. A failed high-temperature print does not just consume machine time. It can consume dozens or hundreds of dollars in material, depending on the part and polymer being used.
Preparing the Build Plate for PEKK-A
Build plate preparation becomes especially important when printing expensive high-temperature materials.
The process described uses Nano Polymer Adhesive on a thoroughly cleaned build plate. The adhesive was originally developed for materials such as PEEK and ULTEM and is also used with a broad range of other polymers.
For inexpensive materials, a single coating can potentially support many prints. With high-temperature engineering polymers, however, the priority is process reliability rather than maximizing the number of prints obtained from a single coating.
A failed print late in the build can waste significant quantities of material and several hours of machine time. Preparing the surface carefully helps reduce that risk.
Why PEKK Filament Drying Is Critical
Moisture management is one of the most important parts of printing high-performance polymers.
The PEKK-A spool used in the example was conditioned in a vacuum oven before printing. It was then moved directly into the printer’s heated filament environment.
This matters because warm filament can absorb moisture from the surrounding air more rapidly than filament at room temperature. Keeping the material exposed to ambient conditions for an extended period after drying can therefore undermine the preparation process.
The goal is straightforward: dry the material and minimize its exposure to ambient humidity before and during the print.
How to Tell if High-Temperature Filament Is Dry
The extrusion itself provides a useful visual check.
When the PEKK-A was purged through the nozzle, the extrusion appeared smooth and consistent. The process also flushed residual PPS-CF from the previous material out of the nozzle, with the purge gradually changing into clean, clear amber-colored PEKK-A.
Small bubbles in the extrusion can be an indication that moisture is present in the filament. A smooth extrusion without visible bubbles provides a practical confirmation that the material is in good condition for printing.
This is not a substitute for controlled material drying, but it is a useful process check before committing to a long print.
First-Layer Control Is Critical With Expensive PEKK
Before starting the print, the 22 IDEX performs its mechanical and mesh bed-leveling sequence. The first layer should still be monitored closely, particularly when printing material that costs hundreds of dollars per kilogram.
The objective is to identify a problem early rather than discovering a failed build several hours into the process.
For high-temperature materials, first-layer adhesion is more than a cosmetic concern. A part that begins to lift can continue accumulating stress throughout the build and ultimately warp or detach from the build surface.
What Happens When PEKK Filament Runs Out During a Print?
Even a well-prepared print can encounter a simple logistics problem: the spool runs out.
In this example, the filament runout sensor detected that the spool had become empty. The machine automatically cooled the inactive hot end to prevent the remaining filament from sitting at high temperature unnecessarily.
The remaining filament was manually removed and another spool was loaded. After confirming extrusion, the print could be resumed.
There is also a more automated way to handle this situation. If two compatible spools are prepared in advance, the dual-head architecture can allow the second tool to take over when the first material supply is exhausted.
This highlights an important production consideration: knowing how much material is actually available on a spool can prevent unexpected interruptions. When working with smaller remaining quantities, weigh the spool and account for the length of filament that remains inside the machine after the runout sensor is triggered.
Why You Should Let a High-Temperature Printer Heat Soak After Opening the Door
Replacing filament required opening the printer and allowing the chamber to exchange heat with the surrounding environment. With the chamber operating around 100 °C, this can create a significant thermal change inside the machine.
Rather than immediately resuming the print, the process allows approximately 20 minutes for the chamber and machine components to heat soak again.
This is particularly relevant to high-temperature FFF because thermal expansion affects mechanical components as well as the polymer being printed. Allowing the machine to return to a stable thermal condition helps minimize the possibility of restarting the print with components in a different thermal state than they had before the interruption.
Resuming a PEKK Print After a Filament Change
Once the machine has returned to its operating temperature, the print can be resumed from the point where it stopped.
The printer cleans the nozzle and continues the job rather than requiring the entire part to be printed again. In the example, only approximately ten minutes remained after the filament replacement and thermal soak period.
This kind of recovery capability becomes increasingly valuable as print sizes and material costs increase. A runout event does not necessarily have to turn into a complete print failure.
How Should PEKK Parts Be Cooled After Printing?
Removing a high-temperature polymer part from the printer requires some consideration. Several approaches are possible, including allowing the build plate to cool naturally, using airflow, cooling the plate with water, or removing the part while it is still hot.
For the most controlled result, allowing the part to remain in the heated chamber and gradually cool toward room temperature is preferable. Slow cooling gives the polymer time to relax and reduces the potential for thermal shock.
The effect depends on the material, geometry, and thermal mass of the part. Large sections with significant thermal mass can be particularly sensitive to abrupt temperature changes.
For demonstration purposes, the example part was removed while still hot. The part showed limited visible warping and released successfully from the build plate.
What Does This PEKK-A Printing Process Demonstrate?
Printing PEKK-A successfully is not simply a matter of reaching a sufficiently high nozzle temperature. The complete process involves material selection, filament drying, build surface preparation, chamber temperature, DFAM, slicing, toolpath inspection, first-layer verification, and controlled thermal management.
The 22 IDEX combines these requirements into a workflow designed for high-temperature materials. With an established PEKK-A profile, the process can be considerably more accessible than starting from an unconfigured material and developing every parameter from scratch.
The example also demonstrates why industrial polymer printing should be treated as a complete manufacturing process rather than simply desktop-style FFF at a higher temperature.
Where Can PEKK-A Be Used?
PEKK is attractive for demanding applications where chemical resistance, high-temperature performance, and other engineering requirements justify the additional complexity and material cost.
The material is associated with aerospace applications and other demanding industrial environments. Its combination of high-performance polymer characteristics and additive manufacturing can make it useful for complex brackets, fixtures, tooling, functional prototypes, and production components where conventional materials or manufacturing methods may not provide the desired combination of performance and geometry.
The important point is that material selection should begin with the requirements of the finished component, then work backward through the manufacturing process. A high-performance polymer only provides value when the printer, process parameters, part design, and material handling are all capable of producing the required result.
PEKK-A Printing Is a Process, Not Just a Temperature Setting
High-temperature additive manufacturing becomes much more predictable when each part of the process is controlled.
For PEKK-A on the 22 IDEX, that means starting with an established high-temperature profile, designing the component for FFF, inspecting the sliced toolpath, preparing the build surface carefully, drying the filament, watching the first layer, and maintaining thermal stability throughout the build.
Even a relatively simple bracket demonstrates the difference that process discipline can make. When the material is expensive and the chamber operates at elevated temperatures, preventing failures is often more valuable than simply maximizing print speed.
For industrial users, that is ultimately the advantage of a mature high-temperature printing workflow: the goal is not merely to make the printer hot enough to extrude PEKK. The goal is to make the entire process repeatable enough to produce useful engineering parts.