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Dry storage box?  

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martin.m25
(@martin-m25)
Estimable Member
Dry storage box?

Hi,
I was just wondering how you store your filaments? I've searched a while for a container of decent size and found this one:
https://www.emsa.com/en/products/freshness-guaranteed/food-storage-containers/superline-round-40l-colour/ - diameter fits perfectly, but a bit too tall. Material is PP/PE, which has a very low water vapor permeability: http://www.faybutler.com/pdf_files/HowHoseMaterialsAffectGas3.pdf . BTW it's a shame we can't print PP as it is a great (the only?) material to make living hinges.
I bought two kilos of silica gel with orange indicator (search ebay for "silica gel orange") and put a handful in the container in addition to a hygrometer (ebay: "analog hygrometer", €2). The silica gel can be regenerated in an oven (not too hot, else the indicator gets damaged). BTW I did not yet calculate how long it takes for enough water vapor to diffuse into the container to saturate the silica gel. TODO...
After a few days in the canister, humidity with my PETG spool that was out for a few weeks before dropped to 8%. Seems to work.
Any better ideas? I'd like to find a flatter container, preferably metal (diffusion barrier) with airtight lid. Very unlikely though. Other solutions I found on Thingiverse are self-printed ones (quite some effort printing those) or huge boxes from Ikea. Ziploc bags are much thinner (90 um) with accordingly higher water vapor transmission (calculation?).

- Martin

- Martin

Posted : 14/10/2017 6:50 pm
Ido
 Ido
(@ido)
Trusted Member
Re: Dry storage box?

Nice!

I am also trying a few things regarding moisture
- I bought a few large zip-lock Mylar bags to store a single role of filament, like my nylon filament
- I bought two 50L air tight containers to store multiple filament spools
- I bought some silica gel and some sachets for containing 100 grams of silica gel
- I bought a cheap food dehydrator to dry the filament and silica gel, so I dont need to use my food oven

Drying filament with just silica gel is not enough. What I understood, Nylon filament is just as hygroscopic as the silica gel. Thats why I bought the food dehydrator. Also, its important to stay below the glass transition temperature of the filament.

Posted : 14/10/2017 10:12 pm
tobias.k3
(@tobias-k3)
Trusted Member
Re: Dry storage box?

I use IKEA SAMLA boxes to store about 10 spools of filament with silica gel. Seems to work well even without additional seal.

Previously I used vacuum bags for clothings but the opening and re-vacuuming is annoying if you change your filament often.

----------------------------------------------
PRUSA MK2
- Noctua fan 40mm
- MK2/MK3 hybrid extruder

Posted : 22/10/2017 12:33 pm
martin.m25
(@martin-m25)
Estimable Member
Topic starter answered:
Re: Dry storage box?

How much silica gel do you use for the SAMLA box? Some posts show people throwing a tiny 1g bag into a huge box like yours - which probably is no good. Did you check humidity somehow?

- Martin

- Martin

Posted : 22/10/2017 7:36 pm
tobias.k3
(@tobias-k3)
Trusted Member
Re: Dry storage box?

I just ordered a 1 kg bag of silica gel on amazon and put about 300 g in each box. It has a color indicator. If it turns green I bake it out, which I do about every 6 months.

As I am lazy, I didn't make any special desiccant box. I just spread it out across the bottom of the box -> maximum surface

I don't measure the humidity. As long as I have no printing issues I am to lazy 😛

----------------------------------------------
PRUSA MK2
- Noctua fan 40mm
- MK2/MK3 hybrid extruder

Posted : 23/10/2017 10:04 pm
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