Is PETG hygroscopic?
Googling the question seems to give opposite opinions.
I have been printing reliably with my E3Dv6 hot end for many months now, but this weekend I have had a string of print failures due to filament jamming and stripping. Same settings, same model, same printer, same filament; but now it won’t print any more.
I followed the excellent E3D troubleshooting FAQ and figured that the only thing left to check was the filament diameter. I was shocked to find that I was getting mainly readings of 3.3 mm - way too big for the hot end!
My printer is in the cellar, which is rather damp, and the PETG filament spool has been out on the printer for a couple of months now, so it has had plenty of opportunity to absorb moisture. I took the filament off the spool and dried it in the oven at 80C for a couple of hours to see if that would help. Diameter readings are now mostly below 3.0 mm, so, fingers crossed!
I’ll know in 10 hours.
Seems like you answered your own question there. Good luck printing!
Pretty much all filaments will absorb some amount of moisture. The more humid the storage conditions, the more they’ll absorb. Some filaments like nylon or polycarbonate absorb so much, so fast, that they don’t print well unless aggressively dried. Others like PLA won’t absorb enough to make a big difference in a typical home (35-45% RH) but WILL absorb too much moisture if you soak them. PET depends on the blend, brand, pigments, etc. There’s a lot of different versions out there.
All polymers absorb moisture to varying degrees: http://www.curbellplastics.com/technical-resources/pdf/water-absorption-plastics.pdf