3DXTech ThermaX PEKK-A: PAEK Polymer for Heat- and Chemical-Resistant Parts (500 g, 1.75 mm)
ThermaX PEKK-A is 3DXTech's PEKK filament, made with Arkema Kepstan resin. It plays in the same league as PEEK, but 3DXTech themselves are clear that it's significantly easier to print — it crystallizes more slowly and builds up less internal stress. I stock it as a 500 g black spool in 1.75 mm. If you're looking for a PAEK-family ultra-polymer and your printer can hit 375 °C with a heated chamber, I'd start here before jumping to PEEK.
Key Specs
- Made with Arkema Kepstan PEKK resin, per 3DXTech.
- Tg of 165 °C and Tm of 335 °C per datasheet; HDT at 0.45 MPa of 182 °C.
- Tensile strength of 105 MPa and elongation at break of 10% (3DXTech TDS).
- Base resin rated UL94 V-0 at 0.8 mm with low smoke generation.
- Nozzle temp 345–375 °C, bed temp 120–140 °C, heated chamber strongly recommended.
- Must be dried at 120 °C for 4 hours before printing.
Can My Printer Handle It?
It comes down to three requirements — and you need to meet all three. You'll need a hotend that runs stably between 345 and 375 °C, a bed that reaches 120–140 °C, and, following 3DXTech's guidance, a heated chamber at 70–150 °C wherever possible. A closed desktop printer without an active heated enclosure will struggle with layer adhesion and warping. If your printer can't hit those temperatures, don't buy it — it's a waste of money.
PEKK vs. PEEK: Which One Do I Need?
3DXTech puts it plainly on their website: PEKK is substantially easier to print than PEEK and offers a wider processing window. Looking at their datasheets, PEKK delivers a Tg of 165 °C versus 143 °C for PEEK, and an HDT of 182 °C versus 140 °C. PEEK wins on elongation at break (28% vs. 10%). If you don't have a machine built specifically for PEEK, PEKK is the smarter starting point.
Where Does It Make Sense?
3DXTech highlights Kepstan resin's use in aerospace, oil & gas, and defense applications. In practical terms: functional parts that run hot, come into contact with aggressive fluids, or need good flame performance. Keep in mind that those references apply to the base resin — not a certification of the finished printed part.
Technical Specifications
| Property |
Value |
| Material |
PEKK (Arkema Kepstan), amorphous grade PEKK-A |
| Diameter |
1.75 mm |
| Net Weight |
500 g |
| Color |
Black |
| Nozzle Temperature |
345–375 °C |
| Bed Temperature |
120–140 °C |
| Enclosure |
Recommended, 70–150 °C if possible |
| Nozzle |
No special requirements per 3DXTech |
| Drying |
120 °C, 4 h |
| Density (ISO 1183) |
1.29 g/cm³ |
| Tensile Strength (ISO 527) |
105 MPa |
| Tensile Modulus |
3200 MPa |
| Elongation at Break |
10% |
| Flexural Strength (ISO 178) |
134 MPa |
| Flexural Modulus |
2900 MPa |
| Tg (DSC) |
165 °C |
| Tm (DSC) |
335 °C |
| HDT at 0.45 MPa (ISO 75) |
182 °C |
| Flammability |
UL94 V-0 at 0.8 mm (base resin) |
Printing Tips
- Always dry at 120 °C for 4 hours. A kitchen oven isn't ideal — use a dryer that holds a stable temperature. Check out our filament dryers, but make sure the one you choose reaches 120 °C.
- Start in the middle of the temperature window (around 360 °C) and dial it in from there. 3DXTech's own test specimens were printed at 370 °C with a 130 °C bed.
- Close your printer's enclosure and let the chamber temperature stabilize before starting your print.
- Keep the part cooling fan low or off for the first few layers.
- The TDS test specimens used 0.25 mm layer height and 100% infill — if you want to get close to those mechanical values, print solid.
Frequently Asked Questions
What diameter and weight is this spool?
1.75 mm diameter, 500 g net weight, in black. We verified this against SKU PKK09UN100500BK01 on the 3DXTech website.
Do I need a hardened steel nozzle?
3DXTech lists no special nozzle requirements for unfilled PEKK. What you do need is a hotend capable of sustained printing at 375 °C.
Is a heated enclosure required?
3DXTech recommends one at 70–150 °C if possible. Without an active enclosure you may get away with small parts, but on medium-sized prints layer delamination becomes a real issue.
How much heat can the printed part handle?
The HDT at 0.45 MPa is 182 °C, and 3DXTech lists a continuous use temperature of 260 °C. Tg is 165 °C per the TDS.
Is it flame retardant?
The base resin carries a UL94 V-0 rating at 0.8 mm per the datasheet. This is not a certification for your finished printed part.
Why does the product page say Tg 162 °C but the TDS says 165 °C?
These come from two different 3DXTech documents. We use the TDS value in the table above and flag the discrepancy so there are no surprises.
How long does it need to be dried?
4 hours at 120 °C, per 3DXTech's recommendations.
Is it better than PEI?
It depends on your application. PEKK shows better elongation at break and tensile strength in 3DXTech's datasheets; PEI 1010 has a higher Tg. You'll find both in our technical filaments collection.
