I’m new to using PVA support filament, and have read it is especially prone to absorbing moisture out of the atmosphere. People made it sound like it starts to happen quickly, and if you aren’t supposed to leave it on the machine overnight, what’s the difference between that and doing an overnight print with the roll?
I’m building an enclosure for the printer (BCN3D Sigma, filament lives in the build space), expect the ambient temperature when printing PLA to be ~35 °C, unless I add an active heating element (100 W lightbulb possibly). The question is, do the hygroscopic materials continue to absorb moisture in a warm, toasty environment? And if so, do I need to construct a dry box for the filament to live in as it prints?
A frugal attempt at research brought back this: As noted by the Sciencing.com website article "How Temperature & Humidity are Related":
As air temperature increases, air can hold more water molecules, and its relative humidity decreases. When temperatures drop, relative humidity increases.
After adding an inexpensive thermometer + hygrometer, I can report my enclosure, heated passively with the heat bed, isn’t very effective at raising the temperature and even less impressive at lowering the relative humidity. With the bed at PLA temperature (65 °C) for 2 hours, the temperature raised from 22 °C to 28 °C, and the relative humidity lowered from 32 % to 29 %.
I may go for an active heating element and will report back on what happens when the chamber is hotter.