Tips for using PEKK
First of all, you should preferably use dimafix in lacquerrather than 3Dlac which will perform better at high temperatures. On the other hand, printing on a glass-ceramic plate is possible, but PEKK will adhere better to a PEI surface. If your part is relatively small, it will still make printing easier, larger parts will have much more shrinkage and warping (peeling of the part) will be very strong.
Adjustments to be made
- You can try on a glass tray if the room is small
- Use Dimafix
- Tighten the nuts of the compressor, the filament being very hard, the drive must have a good tightening. (ULTRA: tighten the 2 nuts to have about 3mm of thread sticking out)
- Load the filament manually at 340°C (or change the loading temperature in the machine settings). Be careful with the first load, depending on the last material used, it can quickly carbonize when heated to 340°C. Ideally, you should use Ultra Purge first. Otherwise, start loading the filament when the temperature is rising and has exceeded 240°C to start evacuating the old material as long as the temperature is not too high.
- Use a low print speed, these materials do not print well at high speeds. Try a speed of 40mm/s to start with.
- A dedicated head for these materials is recommended (switching from ultra-technical to conventional will always be quite problematic and will require systematic cleaning and purging, and may cause problems when reprinting conventional if PEKK residues are still present in the thermal barrier or the nozzle for example).
Machine maintenance for this type of material (PEEK, PEKK, PEAK)
Printing ultra-technical products at high temperatures places very high demands on the machine. It must therefore be maintained accordingly on a regular basis, namely :
- Tighten the screws of the bearings and frame angles to about 1.2Nm quite regularly (plastics work a lot at high temperatures).
- Tighten the screws of the extruder (holder and motor) and the belt locks.
- Place all motors on the bearings.
- Grease the shafts with PTFE liquid oil because the high temperatures will cause the oil to dry out much faster.