Filament breaks even when not printing, too dry?

Hey all,

My rolls of PLA seem to have become much stiffer than they were originally. THey break overnight (even when not printing) and one roll is so bad, I cant even bend the filament sufficiently to put it in my extruder without it snapping

THey are stored at room temperature room, in a room with walls and ceiling covered in cork, and Im wondering if its not too dry. Since I know humidity is often a problem (bubbling), Im reluctant to soak them in water, anyone have a tip what I can do to revive them or anyone confirm or deny my suspicion ?

Same problem here!


FWIW, I stored them overnight in a bybuilding of the house where its much more humid, and colder, and its bendable again. That goes against all advice I read everywhere (store it dry and warm), so dont take this for gospel.

Its wintertime now thus maybe dry air can be the problem.

At office, by 33% relative humidité, the filament broke every night. At home, by 45% relative humidit, I’ve no problem.

The PLA breaks easily if it’s too cold (and by cold I mean 15-16°). If it’s stored in a room that’s not heated overnight it could the issue.

When stored in a dry and warm (21-22C) room for a few weeks it became stiff and extremely brittle, so I moved them so somewhere cold (10-15C at night, no more than 20C during the day) and fairly humid, and it has regained its flexibility.

As with most things related to 3D printing, this seems to be a case of “YMMV” / “whatever works for you” / “try and see what happens”. More art than science this hobby :).

Same problem here, it broke after a few hours.
If I put the roll like this after printing it doesn’t break:

Try and set the Z-position to about 150mm, it helps to relieve tension on the filament.

I had the same problem until I printed center hubs for the spool.

Had the same problem: Just give the filament an extra loop/turn so it doesn’t get bent that much.
Have a look:

PS: Doing so since a few days and had no more break till now.

I started having the same issue of brittle PLA.
I got a freezer bag (1 gallon) and put the filament in it with a wet paper towel.
Seems to have gotten better.
One time I did this and let it set over the weekend.
I think the PLA got to much water in it.
Now I will just let it sit for 1 night.

Hope this helps someone.

Different colour PLA behaves differently. For me, black breaks but grey and silver are fine. I keep the PLA in a sealed bag with a desiccant when not in use and I remove the black PLA from the printer after use. As others have said, raising the ‘z’ axis about half way eases the problem. My printer is in a unheated conservatory that has a wide temperature range, 0-36 degrees.

I have to rescind this statement. The center hubs seemed to help by allowing the spool to spin freely, and this allowed the filament to unravel a few turns thereby relieving stress. However, that was in Winter. I’m in the UK and now it is Spring the filament breaks overnight more often. Black still survives being left loaded up overnight, but natural filament is full of fracture lines and in two pieces by the next morning irrespective of where I leave the Z axis.