Thread: Filament dehydrating info

In couple pf previous posts I have referred to dehydrating filaments that have been exposed for some time to the atmosphere.
Some plastics absorb water and if this is left in the filament it can lead to a combo of uneven printing, poorer finish and even reduced strength.

The dehydrator I use is a food dehydrator like this


The other thing I use the dehydrator for is for processing olives for with I use the highest temp range (~60ºC) - BTW those Olives taste fantastic.

For filament dehydrating I usually use the 40 or 50 degree temp range,depending on how much filament is on the roll, More filament - higher temp., but yesterday when I put 1/4rd of a roll of PLA in the dehydrator for an ON burst I accidentally unknowingly set the temp for 60ºC.
When I used that filament this morning it was printing very poorly, delaminating etc, I thought it was a blocked nozzle, so tried a new nozzle, played around with different print temperatures and eventually I noticed the filament wasn't coming off the roll all that easily.

A closer look showed the filament was stuck together on the roll in a few place and the further it got into the roll the more it was stuck together.
It was even possible to see the areas (white stripes) on the filament where it had stuck together.
X3DPLA.jpg

I contacted the people who supplied the filament and explained the issue to them and they said 60º for PLA is definitely too high a dehydrating temperature . PLA starts to soften at 80ºC and can stick to itself if left long enough.
What's interesting is that PLA is typically printed at between about 190 and 210ºC but otherwise it really is a room temperature plastic.

My cure was to unravel the remainder of the roll which detached the joins and then rewind the roll. Prints just fine now. Luckily I did not have much filament left on the roll but it does make a small case for having a proper winder the can quickly transfer lots of filament from one roll from one roll to another.,

Thanks Bob - I hadn’t though of using a food dehydrator. Pretty sure my daughter still has one

I’ve taken to keeping my spare filament in a sealed esky (biggest sealed box I had) along with some Dampsorb or similar from the green shed. According to the cheap digital humidity gauge that lives in there it’s typically around 16% so much better than out in the open.
Mate at work did similar but his box isn’t as well sealed and the dampsorb only lasts a couple of months before it’s saturated. Still pulls the humidity down to about the same as I get while its active though - he just has to keep an eye on it.

Steve

Originally Posted by OxxAndBert

Thanks Bob - I hadn’t though of using a food dehydrator. Pretty sure my daughter still has one

I’ve taken to keeping my spare filament in a sealed esky (biggest sealed box I had) along with some Dampsorb or similar from the green shed. According to the cheap digital humidity gauge that lives in there it’s typically around 16% so much better than out in the open.
Mate at work did similar but his box isn’t as well sealed and the dampsorb only lasts a couple of months before it’s saturated. Still pulls the humidity down to about the same as I get while its active though - he just has to keep an eye on it.

Steve

Esky is a good idea.
I store my filaments in cheap sealable plastic bags used to compress clothes and linens etc. The bags come with a one way air valve and a simple reverse hand air pump so you can extract almost all of the air out. Mine are cheap and eventually leak but they're better than nothing. One day when all the bags are shot I might buy a quality set.