Which is to say, not very far on this at all but I think I have a good idea on how have my cake and eat it too for desiccant for my spools.
I am finding I can’t get the humidity below about 50% in my AMS and the silica I am using needs constant refreshing.
Well it seems there is stuff called activated alumina that is pretty good and honestly about the same costs as silica beads, but I need to be able to put it in the oven to refresh it. Which doesn’t work well with my 3d printed desiccant holders.
Insert, cheap tea strainers.
It seems I can get ones that are 4cm in width by 6cm in height that are made out of stainless steel that I can actually put straight in the oven.
So, I am working on getting the parts and items but was wondering if anyone else has done this or have any suggestions before I start grabbing stuff?
I’m not sure, but you should be careful while handling this stuff. It seems like it’s hazardous - the dust it produces in particular. You’re not supposed to handle it without gloves. I also can’t find any info about drying it out safely if the dust it produces isn’t supposed to be breathed in.
Maybe you’ve done this research already, and I’m overthinking this, but whatever you wind up doing, just be safe.
https://www.vanairsystems.com/wp-content/uploads/2019/03/activated-alumina-msds-sheet.pdf
https://ivysads.com/wp-content/uploads/2024/05/SDS-Activated-Alumina-P400016-M001-210-213-214-AA-2024.pdf
Way over thinking it. It’s not hazardous it even says it’s stable and non hazardous in the document you provided and can even be disposed of exactly like any other non flammable trash when done.
It’s a desiccant so it’s an irritant cause it can dry your skin or eyes. And it’s a very strong desiccant that absorbs water very well.
Silica actually has the same warning about washing your skin and avoiding dust. Same reasons just one is slightly better at it.
Activated Alumina is actually already used in lots of things you may interact with like industrial water filters or whole house ones, it’s used to clean cannabis and vape oil, and it’s even used in prosthetics.
You are way overthinking it. Like California putting a cancer warning on chocolate cause you can technically eat too much of it.
@Krauerking @PlasticExistence they’ll have subtly different drying profiles. Silica gel had a higher capacity but will maintain a generally higher relative humidity. Check the graph here out https://www.impakcorporation.com/desiccants
Activated alumina doesn’t appear to be as effective as molecular sieve at low humidity from a lit. search.
You should check for air leaks in the system first. When I lose Desiccant this is usually why.
P. S. Silica gel can be regenerated.
The alumina can be regenerated as well.
I am going for the activated alumina because of the different drying profile and it’s much more hygroscopic nature. As of now I can’t get the humidity low enough from the general humidity of room to be anywhere near the level of dry recommended for TPU and PETG which I am having some issues with.
I think it’s just from opening and closing the AMS in a relatively high humidity environment. It stays consistent once it settles but is saturated to green quickly by it.
I don’t know if it’s that it was cheap and less effective or whatever but my experience has been middling and I’m willing to try something else.
Plus the idea of having the desiccant in a container I can throw directly in the oven to more quickly handle the refresh seems like a better idea than the act of removing the desiccant each time to try and regenerate it.
@Krauerking you could try molecular sieve if that doesn’t work. It’ll get you down to very low humidity also, it’s standard use on 200bar compressed air systems which need to be very dry. Although regen temps are quite high compared to silica gel.