Moist-X-tractor (Dehydrator) by RobWLakes

Last crawled date: 3 years ago

ABS is a great plastic, but its hygroscopic properties cause it to absorb humidity from the air. This has two nasty effects. First it swells the plastic slightly and this distorts the fine tolerances many 3-D printers expect, and can cause blockages, jamming and stretching of Bowden tubes etc The second is the high temperature required to print in ABS is around 240C and the moisture content can turn to steam as the plastic is extruded, causing spitting and erratic plastic flow. Now that I am on my second print head (the first died from causes most likely from the above problems), I was determined to work out how to store my plastic filament better.
My wife provided the inspiration. We have two problems in our downstairs rooms. In winter they have condensation on the windows and mould develops in cupboards. In summer we can have sea mists come in off 90 Mile Beach and the relative humidity shoots up to 70+%. So I remembered she buys plastic buckets that dehumidify the rooms.
I asked for one, then rigged up an old computer cooling fan and a plastic storage box. In went the reels. I left them for a matter of weeks and when I returned to the 3-D printing the creamy, bubble free ABS was delightful. So to show my gratitude and boost sales (not serious of course) of Dehumidifier kits I designed a proper fan mount and a rotating exhaust vent to direct the dry air towards the reels. It also allows me to keep a supply of dehydrated bags of silica to put into plastic bags for long term storage for filament.
Just note though, as the dehumidifier chemical works, it dissolves itself, this resulting liquid is strongly caustic (ie can burn skin) so see below, and follow the manufacturers directions of how to dispose safely.
Edit: One of those Dehumidifier kits in the plastic storage box shown has been going for nearly 3 months now and only about half exhausted. So quite economical.