broken PLA filament

[Dim3nsioneer 540]

Recently I had serveral breaks in PLA filament (not from Ultimaker) which was still mounted to the Ultimaker but not used (therefore stayed at the same position).

It's clear that (standard) PLA is a quite brittle material. But these breaks did not occur when the PLA was 'fresh' out of the plastic. Of course I had to twist the filament by 90° between reel and bowden tube.

The room I run my Ultimaker has a temperature between 19 and 25°C and a relative humidity of 50-60%.

I would like to ask the PLA experts among you what might be the cause for these breaks. Humidity? Too much stress in the filament? Poor quality of the filament?

thxs

 

[IRobertI 486]

I can't comment on the humidity because I have no experience there but it could certainly be poor quality. I got a spool of filament a year or so back that was terrible. The first few meters of it seemed to work just fine but then... I could barely unspool it very carefully by hand without it breaking. It was like handling glass.

 

[3dcase 37]

same problems here....:(.

Any tips and tricks on storing PLA?

New rolls are obvious, but what with the opened ones?

For welding rods I used an old refrigerator, with a timer for the light bulb, to keep them dry..

Would that help? (If the moisture is the problem?)

 

[matengi 0]

I had failures like this with filament delivered on spools with a very small inner diameter, about 20mm. Having used about 1/2 to 2/3 it inevitably broke.

The filament had so much tension that it hardly slided through the boden tube. It was obvious that it broke because of bending it back straight, coming from a diameter too tight. I tried to transfer it to a can with larger diameter, to let the material relax. But within two days, the filament completely disintegrated into hundred of small pieces of 5-10cm.

Next trial will be a transfer to an empty standard spool, and then I want to put it immediately in an oven at ~50-60°C to support relaxation.

 

[Nicolinux 287]

As for storing filament I just took a big plastic bag and grabbed all desiccant packs I could find and threw them together with the filament in there.