Prusament PETG sticking behaviour changing within time (change in filament properties?)
Hi All,
Had a struggle to find anything directly touching this topic, so created a new one.
I have had Prusa printers already several year and they have been reliable workhorses. I'm using 99% of the cases Prusament PETG. The recent roll change opened my eyes on how the PETG sticks to the Textured-PEI. The old roll (inside a dryer) started to stick too well to the Textured-PEI. When I changed similar roll straight from the original package (maybe 1 year old), the sticking was perfect. Meaning, when the heatbed cooled down the print popped up itself. This is not the case with the roll I had in the dryer. What is your opinion why this happens? All the settings were identical between the two rolls (default prusament PETG settings in PruseSlicer). Didn't clean the PEI between the prints and that hasn't caused any differences between prints in this kind of cases. I had the roll in a dryer, so weren't expecting the moisture to cause the issue. Maybe could check the drying temperature. What is your experience, is the properties changing somehow or can it be just moisture? Is there any way to mitigate the gradually increasing sticking issue?
RE:
Do not print PETG in the PEI directly because it can fuse together and trying to separate them can end in getting the sheet being damaged. Change the sheet to something else or if tou don't have it then use glue stick to decrease adhesion.
Filament properties differ in the same brand due many factors, from which the pigment or infill used to make material matte makes it different. Add to it the fact that material ratio can change over time ( adding more G to PETG), or any other additives, storing it in certain conditions ( vehicle fumes), sunlight, higher/lower temp can cause things to change.
There are known examples where people were saying that white filaments are the hardest to print ( sometimes not sticking), some people reported spools of filament turning into a total confetti over time (PLA).
And sometimes there are mislabeled spools, sometimes PLA marked as PETG and vice versa 😉
See my GitHub and printables.com for some 3d stuff that you may like.
RE: Prusament PETG sticking behaviour changing within time (change in filament properties?)
Thanks for the comments! I'm actually using the Textured-Steel sheet. Maybe the way I wrote earlier was not clear. The filament rolls were excactly the same filament, same manufacturer (Prusa) and same colour. The first filament roll was in the beginning working like a dream, but during time it starts to stick too well. So something is happening during time, but I try to understand what it is, if I'm able to influence on it.
RE:
Not easy to make a diagnose without seeing pictures. Possibly former prints left a residue of very small PETG particles embedded in the crevices of the textured plate, so the bed adhesion of further prints increased too much ?. Just a random theory.
Moisture usually doesn’t affects plate adhesion noticeably. Instead, it creates other problems like filament sticking to the nozzle, blobs and zits all over the print ( specially with certain infill patterns ), increased oozing/stringing and/or worse interlayer adhesion.
As _KaszpiR_ wrote, sometimes different colors of the same manufacturer behave in different ways, but if it’s the same color of the same brand and batch, assuming the nozzle/bed temperatures and printing speeds haven’t changed. the unexpected issues are probably related to moisture or a printing plate in need of cleaning. In the case of the MK3 series, an unexpected change of the Z offset can play also a role. No reason for that if the nozzle and bed plate are the same, but it's worth checking.
On any case, I’d check carefully that plate for any residue, cleaning it carefully with HOT water and a few drops of unscented dish soap to make sure it’s perfectly clean.
RE: Prusament PETG sticking behaviour changing within time (change in filament properties?)
I remember noticing the same behavior with my former MK3S+. Now I noticed that with my current XL printer. I'm cleaning the plate with IPA every now and then, but it is true that there might be some residue, because IPA is not dissolving PETG completely. Would be worth having a go wit the soap + hot water. I would say that the print quality is still ok. It is jut that it sticks too well :). The attached picture is the last print before I changed the roll. Small piece from the bottom broke away, because it was sticking so hard.