PLA breaks up in feed tube overnight, becomes brittle

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Joined: 2011-08-10
Posts: 1
Points: 22

We recently got a BFB 3000 Plus dual head.  So far it seems to work pretty well, but the PLA material(BfB brand), when left in the feed tubes as little time as overnight, breaks into pieces and the tube has to be removed to get them all out.  When I remove the material after using the machine for the day it doesn't get brittle.

I did leave a fresh piece out in the room over the last weekend to see if it was the room environment and it remained flexible, and the brittle pieces remained brittle.  The only thing I could find in searching was this thread: , and there doesn't seem to be much of a resolution to the problem.

Are others having this problem? Is there a solution already?  Any help is appreciated.

Joined: 2009-06-15
Posts: 677
Points: 837

 There has already been a bit of a discussion in another thread started by me.  My PLA always breaks up if I leave it in the PTFE tube.  I take it our whenever I stop printing for any length of time.  (As you say over night is enough).  There was some discussion about PLA attracting water which could make it degrade and to store it somewhere warm and dry.  There is also a sell by date on BFBs PLA now and mine is definitely older as I bought a lot of reels at once of different colours.  ORBI PLA does not have this problem but is very different.

 I tried leaving the bed heater on thinking the pla would keep soft but that did not work.  

I think it is just that it is straightened out through the PTFE and it does not like it.  When you reel it in it does recoil into quite a tight circle.  

So no solution apart from take it off the machine.  I was going to look into an 'above the machine' reel holder so the PLA does not have to straighten out so much (and would be easier to get off when it breaks)