How do I dry filame...
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How do I dry filament which has been exposed to the air?  



All materials have different requirements for drying. Keeping them dry ensures that print results are predictable and consistent.

How do you store and resolve wet filament problems? What sort of symptoms do you see from wet filament?

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My solution to wet filament is a set of airtight plastic bins and a rechargeable de-humidifier. I find that I have to recharge the de-humidifier about once every 6 months. I also keep filament in its sealed bag until I use it and put it back when I am done, and then put it in the bin with the humidifier.
Nylon, ABS, and PLA are the only filaments that I have seen much moisture effect with. PLA and ABS get really brittle when they get wet and both will swell in the Bowden tube during printing, leading to filament feed errors. Nylon bubbles and pops and I can see steam coming out of the nozzle while printing if it is wet.
I have seen people report that ColorFabb nGen Clear gets brittle and starts to yellow if exposed to enough moisture, but have not been able to replicate this myself.

I'm new, but I hear food dehydrators work. I bough one at Aldi's for $12. I cut the bottom out of two of the trays, and can dry 2 at a time, or recharge a desiccant bag.

I use a PrintDry dehumidifier and then store them in PrintDry vacuum boxes. PLA seems to be the only filament I use which suffers from humidity problems and it shows up as a very rough surface. TitanX ABS seems to be able to stay in the machines indefinitely without any noticeable degradation.

1 Answer

In thick airtight zip-loc bags with silica gel packs wet filament dries out over time.

This is a roll of SR-30 soluble support material, that I bought second hand. SR-30 is very
hygroscopic, similar to PVA. The roll was manufactured in 2017 and printed very badly. Lots of steam bubbles
in the extruded filament, excessive oozing, blobs and zits on the support structures. 

Mojo filament cartridges (they are called Quickpack Print Engines) are sealed in aluminium coated pouches and contain about 200 gramms of desiccant. The original pouch had some holes and the desiccant was already spent. I removed the lower part of the pouch and replaced the spent desiccant with fresh regenerated silica gel.

After two month of drying inside the zip-loc bag with three new sets of silica gel packs the moisture level of the air inside the pouch is now at 6% relative humidity. Recent test prints with this roll of SR-30 were successful and produced no steam bubbles, only a little oozing (which is normal for Stratasys printers and dealt with by wipers and brushes) and acceptable support structures. 

When the filament is already dry I have to regenerate the silica gel packs every two to three month in a hot air oven at 110°C to maintain optimal print results. This also applies to Stratasys ABS-M30, TitanX and PETG. They print best when they are bone dry.

If there is enough time silica gel packs and thick plastic bags will dry filament in a safe and reliable way.

Thick plastic bags with a moisture barrier are highly recommended.

Mojo Quickpack Print Engine stored in thick zip-loc bag with silica gel packs and a hygrometer


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