Polyvinyl Alcohol is a water soluble, vinyl based polymer that is able to slowly biodegrade in the presence of the right micro-organisms. PVA filament is commonly used in 3D printing as a support material for PLA during dual-nozzle 3D printing.
The benefits of using PVA as a support material for PLA prints are that it allows printing of more intricate or elaborate designs that would not be suitably printed with PLA supports. For example if the final product required supports that would not be accessible to remove or would leave unsightly marks/damage after post processing. The reason PVA is so good as a support material for PLA are that they have near identical printing temperatures and PVA is water soluble.
PVA is usually printed between 190°C and 200°C, any hotter and you risk deforming the PLA structure. PVA is also prone to burning and clogging the nozzle at temperatures much higher than that. You should always check the Technical Data Sheet as print temperatures will vary between brands.
As mentioned, PVA is water soluble. This makes it a fantastic support structure as all you need to do is soak your final product in water and the PVA will dissolve, leaving you with your PLA product! Unlike cutting or filing support structures, using PVA leaves no trace on your final product. However, because PVA is water soluble you need to take extra care when storing your PVA filaments or they will degrade. Store you PVA in air-tight containers and if need be dry them out in an oven on the lowest possible setting for a few hours. You can read our blog article on general filament storage. PVA is somewhat prone to oozing however this may be avoided by cooling down your PVA extruder whilst it is idle.
Whilst PVA is relatively expensive and can be a slightly difficult to print with, if you're using a dual-nozzle printer and want to greatly expand what you can do with your PLA 3D prints then PVA is an excellent option. Here at Filaments.directory you can select the right PVA filament using our constantly updated list of suppliers and our comprehensive search tool!