Filament Checking and Storage

[cdrose 8]

Hi all,

 

I'm brand new to 3D printing but have a lot of experience in 3D modelling and CAD design. Recently got my second hand (pre-owned) UM3 and extremely happy with it.

I have had problems with the PVA bubbling, popping, burning and grinding which I've read means it's absorbed too much moisture. I think previous owner either didn't store it correctly or during transit it abosrbed moisture as it wasn't bagged up.

 

I've now invested in plastic sealable bags and packets of desiccant, I have also ordered a new spool of PVA to see if I have the same issues. Fingers crossed!

 

I have a few questions:

1. How should PVA look? White/Yellow/Milky?
2. How flexible should it be?
3. How long does it take for PVA to absorb too much moisture?
4. Does the average household room pose a risk to the PVA while using it to print with for long hours?
5. How to identify / check any filament for quality / moisture absorbtion?
6. Same questions for PLA too?

 

I hope this isn't too many questions!

 

Thanks,

Chris

[gr5 2,094]

I don't know all the answers.  The flexibility is similar to pla I think - why - is yours very flexible?

 

The best way I know to test if it absorbed too much water is that it sizzles when you print (and you can also see steam coming out of the nozzle).

 

You want to keep PVA and Nylon extremely dry.  I have dried nylon by setting the bed to 99C and letting it sit for 6 hours under a blanket on the bed.

 

However PVA will melt at that temp so you would have to do it closer to 80C I think - I'd take a snip of PVA, put it under a towel on the bed at 80C for 20 minutes then squish it firmly and see if it changes shape permanently - then repeat the experiment at a few other temps (I seem to remember it is soft around 80C).  Then once you know what's "too hot" I'd heat the PVA for a few days on the bed under a towel at the highest safe temp.  I'm not sure you can ever get the moisture out of PVA with the baking method but it's worth a try.

 

Ultimaker PVA is different than most manufacturers and takes much longer to absorb water (weeks).  However I'm guessing (total guess!) this also makes it harder to dry.

 

 

 

[cdrose 8]

Thanks for your response. I received my brand new Ulti PVA 350g spool and the difference is immediate.

 

A brand new good condition PVA filament is bumpy / rough to the touch, is cloudy and snaps. The used PVA I have is smooth to touch, almost completely clear / see-through and bends easily without snapping.

 

New PVA is on top

 

New PVA is to the left