Can PLA go "bad"? left greasy-looking deposit on build plate - General discussion, announcements and releases

RE: Can PLA go "bad"? left greasy-looking deposit on build plate

Sova — Fri, 08 Aug 2025 15:32:29 +0000

Was it bad before drying or you didnt test? I think that you might have ower heated the pla it drying temperature is betwen 40 - 45 if i remember corectly .

Diem — Fri, 08 Aug 2025 09:52:05 +0000

Can PLA go "bad"?

Yes, if kept warm and moist for a long time it will begin to decay. In a hot compost heap it takes about two years to decay, this may mean returning to the heap through a dozen cycles; in a cold compost heap it lasts for many years. Without other decaying materials mixed in it also takes longer. The moisture is essential, if kept dry it cannot decay.

First layer ripples are most often a sign that your first layer 'Z' offset calibration is set too low and the residue *might* be due to over-squishing the extrusion - it may go away gradually as the plate is used or as it is cleaned between prints.

Cheerio,

Can PLA go "bad"? left greasy-looking deposit on build plate

Kchula-Rrit — Thu, 07 Aug 2025 20:37:34 +0000

I was printing a flat disk using "Prusament" Jet Black filament in my MK3S when I noticed ripples in the first layer. After aborting the print, I let everything cool down to room temp. When I peeled the part from the build plate, I noticed what looked a greasy circle where the part was.

The filament spool is labeled 21.2.2024, which I assume means it was made roughly a year and a half ago. It was dried with a "PrintDry" filament dryer, set at 55C for two runs of five hours.

Anything I can do about this, or is the filament just degrading? I pulled it out of its sealed shipping bag a few weeks ago and have had a fair bit of trouble getting good parts out of it.

K-R.