Dry filament

Bambu Lab AMS
1

Maybe is a stupid question, after dried the filament and put them into the ams full of silica gel, after how many days you take out the filament and dry again?

2

Newbie here, but I haven’t had to as long as the gel remains active. I added a RH monitor to my AMS and the current ambient RH inside is 25 so in theory , as long as I keep the RH below say 30 you shouldn’t have to take it out and dry it again. The lowest I ever got filament in my Sunlu dryer was 27 ish ( 10 or so rolls of filament put through it so far. To be fair, in my environment in the winter, I have to run cool mist humidifiers in the neighbouring room just to keep the humidity above 40 lol.

Current RH is 22 and temp is 28.6 C in my AMS

3

The answer to your question would involved the relative humidity and the rate of moisture absorption for a particular filament. I don’t know if filament ALWAYS absorbs moisture from the air or if at some RH, say 50%, the absorption becomes almost zero?
I’m also not sure how to measure the moisture in the filament. Seems the only way I’ve seen is to weigh the filament before and after drying to see how much was removed. I’ve not seen a case where someone weighed filament and it weighed 1005 grams thus 5 grams of moisture.
I’d be interested to learn a little more about the science and calculations…

I could be wrong but I don’t think most folks are redrying their filament from the AMS unless there is a sign of a problem OR the humidity in the AMS was an issue. That being said it seems like it’s always a good idea to dry filament ahead of a print, I’ve not heard of over drying.

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4

Is there an humidity sensor inside the AMS?
if so why not show the exact value?

5

There is one but it’s far from accurate.

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6

Ive noticed that with enough desiccant, the humidity will sit below 10%. I have some rolls that have sat in an ams over 6 months and are still dry. Depends on how often you open it and allow moisture in. Desiccant will dry air but it will not dry filament.

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7

I am always at 10%, should be correct more or less because 2 hygrometer show the same value +/- 1%

That should be possible and very usefull

8

Alot of them only go down to 10%