UltiMaker PVA is a water-soluble support material that allows full design freedom. However, it also takes up moisture from the environment rather quickly, resulting in decreased reliability in printing (oozing, nozzle clogs). Therefore, it is important to store PVA under low humidity and dry UltiMaker PVA when it is subjected to moisture.
Moisture uptake
We studied the moisture uptake of PVA under three conditions:
- Office conditions where the PVA was removed from the package. Average temperature measured was 21°C with 55% RH (relative humidity)
- UltiMaker S Series Pro Bundle, where the PVA was kept in the Material Station. Average temperature measured was 23°C with 21% RH (relative humidity)
- UltiMaker Factor 4, where PVA was in the Material Handling system. Average temperature measured was 24°C with 12% RH (relative humidity)
As is visible in the graph below, the initial moisture content of PVA from the package is approximately 0.7 wt%. When the spool is open in office conditions, the moisture level steadily increases in 8 weeks to more than 4 wt%. In contrast, the S series Material Station only showed a small increase in moisture content from 0.7 to 1.1%. The Factor 4 Material Handling kept the PVA moisture content completely stable at 0.7%.
Printability
Additionally the printing performance was evaluated. As shown below, this increase in moisture content results in an increase in oozing. Above 3.5 wt% moisture content PVA becomes unprintable, resulting in degradation and nozzle clogs. Test description to check on the quality of your PVA can be found here.
In conclusion, it is highly recommended to preserve UltiMaker PVA in good condition using appropriate material handling systems. Whenever subjected to moisture, dry your PVA and perform a print core cleaning.
