I have not much experience with petg but I have tried yesterday. And it has litarelly no layeradhesiom. Printed at 255C bed 70C partecooling off (it warped like hell with partecooling) temp to low? Can the mat degrade? I have it open in the room for have a year for sure…
Layer 0.28-0.15
Perimeters 3 (spiralvase in bagground)
Speed 20-45
#DasFilament-petg black
using a much lower print temp (210°C) and lot of cooling, PET may need drying first. You can spot wet filament as it will leave a rough surface ( https://www.matterhackers.com/news/filament-and-water )
Didn’t realize petg is that hygroscopic. I only stored nylon and pva dry… So I’ll grab a food dryer and try it again
PETG (NOT PET!) is not very hygroscopic. I dont tread it very special. Maybe it realy did suffer from the long storage. But in general PETG printing is as easy and reliable as PLA after you dialed it in.
210 is most likely not enough.
Some tips:
Check and calibrate the extrusion multiplier!
Print it with a more constant speed (can be printed quite fast). Partcooling can cause bad layer adhesion. I use 40% fan (Original Prusa i3 mk2). After printing PLA some first layers can have bad adhesion.
@Carsten_Wartmann yes there is no PET filament as only the glycol modification allow the viscosity needed. However:
Extruder giving 205°C recommendation and https://www.dasfilament.de/filament-spulen-xxl/petg-1-75-mm/204/petg-filament-1-75-mm-2600-g-schwarz is at 210-240°C. You may need higher temp if printing on a smaller nozzle. But however even in worst conditions i never had a layer adhesion issue with PET-G. So impureties may be the key here.
Forget to add some link: https://www.3dpsp.de/petg-drucktipps
I go for water. Because to high temp would.deacrease quality but not layeradhesiom right?
Try turning the fan speed down, I’ve noticed PETG is very sensitive to cooling.
Moisture is definitely an issue with PETG… it doesn’t absorb all that much moisture, nothing like nylon, but any moisture it does absorb will damage the molecular structure when heated to melt temperatures. Typically you get lower strength and more brittle prints with wet PETG, which is something casual users don’t really notice, so PETG has a false reputation for not being sensitive to water absorption.
I’ll second the previous advice… first try cutting the print cooling down to a very small amount of airflow to see if that helps (because that is easy) and then dry the spool.
FWIW my experience with PETG (and I print a lot of it), is that it’s very sensitive to changes in part cooling. I usually run PETG at 257C and 100% cooling fan on a Prusa i3 MK2S, but I have to introduce the fan slowly.
If I go to 100% fan from no fan soon after the first layer, the part has basically no layer adhesion at all on that layer. Introduce the fan over 10 layers (so 10%, 20%, 30%, …) and the layer adhesion for me is very strong – the resulting prints are incredibly strong.
This is with both Rigid Ink PETG and Filaprint PETG.
@Mark_Wheadon I must second this! I have my fan (also i3 mk2) running at 40% constant.