Nope, this is not about preserving the PVA filament, it works just as I described it in the preserving filament discussion, I run a five months test, it works fine.
This is about preserving PVA used in printing. And re use it.
Now, why would one do that?
Saving money? Yes, damn PVA is not coming in cheap.
Saving the environment? Nope, is non toxic to aquatic life and vegetation and it is bio degradable.
Saving headache? Definitely yes. Why?
Here is why: PLA is a glue, like Poly Vinile Acrilate or Poly Vinile Acetate, you know, the PVA used to glue timber together, your furniture. But unlike them it not only melts in water, repeatedly without losing it's properties but it also melt uniformly in set temperatures and once temperatures drop cures back into solid, like a polymer.
And this makes it good for 3D filament printing, while the water solubility makes it great for printing supports that can be easily eliminated with some hot water shower, making life easy in post printing.
I wish there would be such a material that can print at 350 Celsius for the Polycarbonate, but for now... patience.
So why saving PVA to save the headache? Because once melted in water that is no longer just dirty water, it is a diluted glue that bonds together shit like... your drainage pipes under the sink if you wash the supports in a sink, or even worse, in a large print if you use the bath tub to wash away your PVA supports... you might have to remove the whole tub to get to them pipes to change them. How about your underground piping from house to communal mains? You might have to dig the whole yard for that.
Because anything that comes in contact with that PVA water will get bonded against each other and against the pipes walls. Hair, sand, shit, other debris, anything.
So here is my take on this; don't.
Don't wash your PVA supports in any drainage system, use a plastic container, tub, something cheap, wash them in there, save the water, put the container on a 50 Celsius source of heat (Summer sun is good enough, radiator heater, etc) and wait for days to evaporate water.
And at each print you do it again, until a whole reel of PVA is in the tub, in a gel form, which is technically PVA to be re drawn in filament form to be reused.
Than you need to dry that well, to solid state, mince it to mall bits, make yourself a filament making machinery (there is one posted in a discussion here, and some more to come) and re use it to print supports.
I Have no clue how many times it can be reused, I assume it decays with re heating, melting, curing, etc, so chances are after a few re uses it will become useless, but I could find zero information about it. Yet.
Those that know more than I do please step forward and say yours.