Printing with Polypropylene (PP)
I have a core one+ and I've been struggling some with getting PP print quality up. I know it is one of the more picky ones so I've been going through calibration prints to tweak settings in Prusa slicer. I started with a generic flex profile. I did the temp tower and it seemed to have the best quality at 265 C nozzle temp (I left the first layer at 240 C as I've seen references that starting lower helps). I have the bed at 80 C and the nominal chamber temp at 30 C. I'm now doing a retraction test print and still getting the stringing. bumping the retraction length up to 2.5mm (retraction speed is at 40 mm/s and deretraction speed at 25 mm/s) helped some and so far produced the best result. However I still have some stringing at the lower part of the two towers. Is it unlikely to get rid of all stringing for PP or are there additional tweaks I can make? What settings have worked for others printing PP on the core one? Thanks!
RE: Printing with Polypropylene (PP)
Which brand of PP? What nozzle? I've had success printing Yousu PP. If you attach your 3MF file zipped I can load it and advise.
RE: Printing with Polypropylene (PP)
Which brand of PP? What nozzle? I've had success printing Yousu PP. If you attach your 3MF file zipped I can load it and advise.
Thanks for the help, hyiger! I'm using Sunlu PP Natural with a 0.4mm v6 stainless steel nozzle (to make the print food safe - I have some food grade epoxy as well). Here is my zipped 3MF file (it has 2 different types of retraction towers that I was printing serially): PP retraction test. I also tried printing an overhang test: PP overhang test. It was able to print but after about 60 degrees overhand, the quality tanked. I'm not sure if that's just to be expected for PP or if there is something I can do to fix that.
RE: Printing with Polypropylene (PP)
What kind of surface are you printing this on? Are you using PP sheet or tape?
Had a look at your profile.
Some suggestions:
- You need to turn off fans completely for PP or it will warp and cause layer adhesion problems.
- Other layers temp seems too high. I would keep it around 235-240
- You have chamber heating disabled. I run my chamber at around 45-50C to control warping.
- Also, I see you don't have shrinkage compensation. PP shrinks a lot. Using Yousu PP for example I measured 0.77% in XY which is more than ASA or PC
- Speeds are way too high. You have external perimeter speed set to 170mm/s, I would cut that in half. This will help with stringing.
- Retraction is too long (2.5mm), I would try 1.5 at the most
- Should increase the # of perimeters to 3-4 instead of 2 since PP is poor for layer adhesion (most brands I've tried).