1 Topic by poppinfresh (edited by poppinfresh 2016-03-06 16:37:46)

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Topic: Brittle Britle Brittle Brittle Brittle

I use PLA a lot and most of the time the prints are great.  VERY strong.

But recently I bought a roll from ebay member tristche

Unlike most of my PLA, the prints I make with it are very brittle and snap easily.
It does print nicely though.  Sharp and crisp.    If only it wasn't so brittle.

It doesn't sputter or act as if there's moisture in it as I have read will happen with soggy filament.

The raw filament on the roll breaks fairly easily as well when flexed back and forth 90 degrees.
Only takes 3 or 4 flexes compared to filament that prints very strong which can flex 15 - 20 times without breaking and even then sometimes doesn't separate.

Is this just poor quality filament, filament that has absorbed moisture or what?
Is it possible to dry the filament and make it more flexible?

Thanks

2 Reply by n2ri (edited by n2ri 2016-03-07 00:08:57)

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Re: Brittle Britle Brittle Brittle Brittle

sounds very (too) dry. like it was made in an area with very arid conditions (extra low humidity) humidity below 20% drys everything out like that even your skin. homes try to maintain 52% while Computer data rooms and some labs more like 48%.-54% for static and damp preventive reasons. wood curing rooms in the 20s but only til proper amount or dryness is reached. wood furniture begins to crack/split in homes with humidity under 36% often. and PLA is more sensitive than Wood or ABS to moisture also sun light can cause it to decompose and crumble over time if not protected, color fades 1st in the later. just another reason I prefer ABS

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3 Reply by 3Dex

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Re: Brittle Britle Brittle Brittle Brittle

Yes it sounds like the filament is rather poor quality. A number of factors can make PLA filament weak and stiff. If PLA is left too long exposed to the air then it can become very stiff and can easily be snapped. This can be due to moisture absorption.

I would recommend trying to dry the filament out although if the whole roll is like that then its going to be a difficult and time consuming job.

Higher quality filament is more resilient to becoming stiff over time.

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4 Reply by usagi

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Re: Brittle Britle Brittle Brittle Brittle

PLA doesn't have to sputter or pop to have absorbed enough moisture to become brittle.

dry the filament out. put it in a sealed container with some dessicants for a couple weeks. or put it in a food dehydrator.

5 Reply by poppinfresh (edited by poppinfresh 2016-03-14 16:06:15)

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Re: Brittle Britle Brittle Brittle Brittle

Would warming it carefully in an oven help?   I would imagine the temp would have to be kept well below the liquid state temperature.    It melts around 175C  (347F)  so maybe 250F max for an hour in the oven?

Or maybe even 150 - 175 if 250 is too high ?

6 Reply by Morganism

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Re: Brittle Britle Brittle Brittle Brittle

Yes, it is possible to dry it out in an oven. You just need to go over the boiling point of water 100C (212F) to dry it out. That way you avoid any chance of possibly melting the plastic.

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