Professional-Grade Printing Instructions & Best Practices (2025 Edition)
Printing genuine Polyether Ether Ketone (PEEK) is the ultimate test of any FDM/FFF system and operator skill. This comprehensive, manufacturer-approved guide contains everything you need to achieve repeatable, high-performance results with SUNLU PEEK filament.
Target audience: Experienced engineers, industrial 3D printing technicians, R&D departments, and certified service bureaus. This is not a beginner material. Failure to follow these instructions will result in clogged nozzles, delamination, warping, or permanent damage to equipment.
1. Mandatory Printer & Environment Requirements
| Requirement | Minimum Specification | Recommended |
|---|---|---|
| Printer type | Fully enclosed, actively heated chamber | Industrial platforms (Intamsys FUNMAT PRO 410, Vision Miner 22 IDEX, Roboze, 3DGence Industry F420) |
| Maximum nozzle temperature | 450 °C continuous | 500 °C capable hotend |
| Chamber temperature | 80–120 °C actively controlled (±2 °C stability) | 90–100 °C with circulation fans |
| Bed temperature | 150 °C continuous | 160–180 °C capable |
| Hotend | All-metal, no PTFE anywhere in the hot zone | E3D Volcano/Mosquito Magnum+, Slice Engineering Copperhead, Dyze Typhoon |
| Nozzle material | Hardened steel, ruby, or tungsten carbide | 0.40–0.60 mm ruby nozzle strongly preferred |
| Extruder | Direct drive, ≥70 N torque | Bondtech BMG, Hemera XS, or servo-driven |
| Build surface | PEI sheet, Garolite G10/FR4, or glass with adhesive | Vision Miner Nano Polymer Adhesive or 3DLac Plus |
| Drying | 120 °C for a minimum 8 h before every print | Dedicated filament dryer with <0.005 % moisture |
| Ambient room humidity | <20 % RH | Climate-controlled printing room |
Consumer machines (Prusa, Creality, Bambu Lab, Ankermake, etc.) are not suitable and will be destroyed.
2. Filament Storage & Drying (Critical)
- SUNLU PEEK is vacuum-sealed with molecular sieve desiccant.
- After opening, store in a dry box at <8 % RH or dedicated dryer at 80 °C.
- Pre-dry every spool: 120 °C for 8–12 hours (16 hours if spool was exposed >4 hours).
- Moisture content must be below 0.02 % (150 ppm) to prevent hydrolysis and bubbling.
3. Proven SUNLU PEEK Printing Profiles (2025)
| Parameter | First Layer | Subsequent Layers | Notes |
|---|---|---|---|
| Nozzle temperature | 410–420 °C | 395–410 °C | Start high, then reduce after layer 3 |
| Bed temperature | 150–160 °C | 140–150 °C | |
| Chamber temperature | 90–100 °C | 90–100 °C | Maintain throughout entire print |
| Print speed | 20–25 mm/s | 30–40 mm/s | 30 mm/s gives best mechanical properties |
| Layer height | 0.15–0.25 mm | ||
| Infill | 100 % for functional parts or Gyroid 40–60 % | ||
| Perimeters | Minimum 4 | ||
| Flow rate | 100–105 % | Calibrate with single-wall cube | |
| Cooling fan | 0 % (completely off) | Any airflow causes instant warping | |
| Retraction distance | 0.5–0.8 mm | Very low to prevent oozing | |
| Retraction speed | 20–25 mm/s | ||
| Z-hop | Disabled | ||
| Brim | 15–25 mm wide | Essential for adhesion |
4. Bed Adhesion Techniques That Actually Work
- Vision Miner Nano Polymer Adhesive (gold standard) – apply thin, even coat while bed is 120 °C
- PEEK-specific high-temp glue (3DXTech ThermaX HTS or Magigoo HT)
- Garolite G10 sheet + thin layer of PVP glue stick (surprisingly reliable)
- Clean PEI sheet + 420 °C first-layer nozzle temp + 20 mm/s speed
Never use hairspray, ABS slurry, or standard blue tape.
5. Post-Processing: Annealing Protocol (Mandatory for Full Performance)
Unannealed PEEK only achieves ~30 % crystallinity → HDT ≈ 176 °C Properly annealed PEEK reaches 35–40 % crystallinity → HDT >310 °C
Recommended annealing cycle (in oven with part embedded in fine silica sand or on PTFE sheet):
- Ramp 3 °C/min to 200 °C
- Hold 2–3 hours (add 30 min per 10 mm of maximum wall thickness)
- Slow cool 1 °C/min to 140 °C
- Natural cooling to room temperature
6. Safety & Maintenance Precautions
- PEEK printing temperatures exceed PTFE decomposition temperature → excellent ventilation or fume extraction mandatory.
- Wear nitrile gloves when handling hot nozzle – molten PEEK sticks to skin and causes deep burns.
- Replace nozzle every 200–400 g of PEEK printed (carbonised residue builds up).
- Perform cold pulls with cleaning filament after every spool change.
- Never leave printer unattended during PEEK prints.
7. Troubleshooting Quick Reference
| Symptom | Cause | Fix |
|---|---|---|
| Severe warping | Chamber too cold or fan on | Increase chamber to 95 °C+, ensure 0 % fan |
| Layers not bonding | Nozzle temp too low / undried filament | Raise nozzle 10 °C, re-dry filament 12 h |
| Nozzle clogging | Moisture or carbonised residue | Dry filament + cold pull + new nozzle |
| Stringing/oozing | Retraction too low | Reduce nozzle temp 5–10 °C, retraction 0.8 mm |
| Brittle parts | No annealing | Perform full annealing cycle |
Final Words from the SUNLU Engineering Team
When printed and annealed correctly, SUNLU PEEK delivers:
- Tensile strength 100–110 MPa Continuous use temperature 250 °C Short-term peaks >300 °C Near-zero chemical attack UL94-V0 flame rating Fatigue life comparable to injection-moulded PEEK
This is the same performance used in jet engines, Formula 1 cars, spinal implants, and deep-well equipment — now available in 1 kg spools.
Master these parameters and you will produce end-use parts that simply cannot be made with any other desktop or prosumer 3D printing material.
Print responsibly. Print PEEK.