PA (Nylon) before and after drying...
I thought that i'd add my experience of importance of having a dry filament, for all those "nonbelievers" (me including in some degree...). I have PA12-CF filament from Inslogic for "demanding" prints. I removed it from original vacuum package some 6 months ago when i've had to print one item. Then i've had it in a "vacuum bag" which came out that it wasn't so sealed as original after all.
Yesterday i've had to print another item and "the dirty one" on the picture is a result of printing directly, without drying. After drying for 12 hours (overnight) in Creality filament dryer a second one from the pic came out.
Clear proof that filaments MUST be dry... especially those "demanding" ones...
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Nylon in particular (especially PA6) has to be throughly dried before a print even if stored in a dry box. I've found that PA6 and PPA (including the CF variants) have to be dried while printing if the print is for more than a few hours. I've dried PA6-CF in a dryer at 85° for 12hrs and it wasn't enough. It had to be dried for 24hrs to get a decent print off. PA12-CF is much easier to work with but it's also more expensive and Prusa's PA11-CF is way over-priced.
I still use Nylons on rare occasions for my rocketry parts since is has toughness, chemical/oil resistance, wear capability and heat resistance all in one material. But otherwise there are easier materials to work with. Example, if you need chemical resistance and a light-weight part then PP-CF is much better, larger parts are a PITA to print but then you don't really need to dry it. And for strong, general purpose parts I've recently switched to PET-CF as my "go to".
PPA-CF is a superior alternative to PA12-CF but it's at the very edge of printability on a Core One. A 290° is at the bottom end of the temp range.
RE: PA (Nylon) before and after drying...
I mostly print PETG and PLA, too, more rarely ASA and ABS.
I bought two small rolls of PA from a friend (PA6-GF25 and PA12CF), more for learning purposes than for serious work. Since i do have a roll of PA6 i appreciate your findings about drying needs! (i have yet to print with it...).
I printed this small part with PA for my motorbike front shield (screen) holder, since printed with ASA tends to break after a few months (i guess from vibrations), so i'll see if this is any more rigid. However, i've read that PA is more hygroscopic, so i guess i'll paint it to protect it a bit... can't hurt...
These filaments are quite expensive, yes, so they are really only for occasional and serious work. I printed this part with pla first only to see if it fits to produce as little waste as possible.
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I printed this small part with PA for my motorbike front shield (screen) holder, since printed with ASA tends to break after a few months (i guess from vibrations), so i'll see if this is any more rigid. However, i've read that PA is more hygroscopic, so i guess i'll paint it to protect it a bit... can't hurt...
This is actually a good use case for PA6 or PA12 since it will hold up to this kind of abuse. Problem though is you need to anneal the parts and possibly water treat them before fitting or you will have problems with faseners loosening due to creep. PA12-CF is the better choice but then nylons have really poor UV resistance so over time it will get brittle and snap off. Sealing it will give better UV resistance but then you lose some of nylons better traits which is ductility.
My opinion is the best material for something like this is PC Blend. ASA is still a decent choice but depends on how you print it, i.e. the part orientation relative to load. So if you reorient the part so that the layers run with the load that might solve your issues with brittleness.
Short answer is PA12-CF is more durable than ASA but only if you UV coat it. PC Blend is a good alternative but it also needs to be UV stabilized.
RE: PA (Nylon) before and after drying...
Good advices, thanks. I'll anneal it, then i'll see over time, i guess. From i've looked on the videos it will 'moisture condition' by itself when leaving outside for a week or so.
If this goes south i guess i'll just print 5 -10 sets with ASA and just change them every few months... 🤣
RE: PA (Nylon) before and after drying...
From i've looked on the videos it will 'moisture condition' by itself when leaving outside for a week or so.
If this goes south i guess i'll just print 5 -10 sets with ASA and just change them every few months... 🤣
That is very true. And after you apply a UV protection coating you should be good to go.