Verbatim PLA Brittle

I’ve been using Verbatim PLA now for quite a while, with great results. However, lately I have been finding sections of filament that are extremely brittle. Without exaggerating, it is about like uncooked spaghetti. I have actually had filament spontaneously break in several places within the guide tube while the printer sat unused for a few weeks.

And I say “sections” of filament, because an entire roll won’t be bad, it remains flexible and pliable in some sections, and then suddenly I will encounter a brittle section. So far I think all of the affected filament has been black, and from the lot number “PKB-385-AC”. At first I thought it might have been from UV exposure (the printer is near a window), so I took a section of filament off of one affected roll, verified it was pliable, and then set it in the windowsill. After several weeks in the sun, the sample remained pliable.

I have contacted Verbatim THREE TIMES now and have not received even an acknowledgement of the problem. Generally I have had great success with this filament, and would like to continue using it, but I would like to find out what’s going on and see if anyone else is experiencing it. I am also using other colors of the same filament and to date I have not found any that is brittle.

I had exactly the same poblem with Matterhackers PLA. I eventually found that the problem was temperature. We live on Cape Cod and our house is cool, 63 day, 55 night and colder when we are away in winter. You are right: there are brittle sections of filament on the spool.
I wound up mounting the spool over the Taz 5 frame, (no tube) to reduce bending stress, particularly as the spool gets near empty, and I mounted a ~20-30 watt flood pointing at the filament as it come off the spool. Never a broken filament since. I also added a bar resting on top of the filament on the spool to provide some friction. BTW, I have never had a problem with moist filament since adding the heat lamp; it seems to drive out the moisture as it comes off the spool.


Interesting. Whatever is causing it is permanently altering the filament in some places, but not others. That makes me wonder about temperature, wouldn’t that affect the entire roll uniformly? The bad filament I have is only brittle in some spots, still pliable in others.