AMTechniques’ new vacuum filament dryer [Source: AMTechniques]
There’s a new concept for preparing 3D printer filament: vacuum drying.
Many of us are familiar with the practice of at least keeping our not-in-use 3D print filament spools in sealed bags with a packet of desiccant to keep the moisture out, and some even have dedicated filament drying equipment.
Filament Drying Overview
What’s all the fuss about filament drying?
It turns out this is a challenging issue that threatens to corrupt 3D print quality and even the reliability of 3D printing operations.
Many of the most commonly used 3D print materials, such as PLA, PETG, ABS and especially Nylons are hygroscopic. That is, they tend to absorb moisture from the air.
While these moisture-soaked filaments may looks pretty much the same as always, they act quite differently when attempting to 3D print them. As they pass through the hot end the absorbed moisture boils.
The expanding water vapor bubble can cause a number of issues, such as a gap in a print where material was expected. Changes in flow rate due to bubbles may generate blobs. Layer adhesion can be affected as well, to say nothing of the surface quality that is likely bubbly in appearance.
Filament Drying Solutions
To overcome this, most professionals dry their materials. Usually this is done by heating the material to something less than the glass transition temperature for a time period. The moisture then evaporates out. However, you have to be extremely careful: if the heating temperature is just a bit too high you’ve suddenly corrupted the filament as it could distort its shape.
That’s not a good thing to happen to a highly precise filament for which you paid good money.
Many filament dryers exist; we have one in our lab here. They are much like food dryers in that you can set a specific temperature and sometimes a timer. The filament supposedly dries and then can be used. Sometimes the dryer allows direct feeding of the filament from the dryer to the printer to avoid possibility of humid exposure.
Vacuum Filament Drying
Now a new company hopes to change your thinking on filament drying. Netherlands-based AMTechniques has developed what they call a “vacuum filament dryer” that uses a different approach.
Instead of heating the filament to a questionable temperature, they instead lower the air pressure in a sealed chamber containing the filament. The lower air pressure drops the boiling point of water significantly, so that even just a touch of heat will rapidly cause all the moisture to evaporate.
Wet vs Dry 0.2mm 3D print results when using AMTechniques’ new vacuum filament dryer [Source: AMTechniques]
AMTechniques says that a three-hour session in their vacuum filament dryer is sufficient to near-completely eliminate any trace of moisture in the filament. They also say that previous techniques are not able to do so, and that there is always some moisture present, even after traditional heat drying.
This approach seems quite sensible as it not only dries the filament but also prevents the possibility of damaging the filament. If the price is right, it could be quite a popular device.
AMTechniques launches their Kickstarter for the device today.