All You Need to Know About PVA for 3D Printing

PVA, or polyvinyl alcohol, is a material widely used in the 3D printing industry due to its ability to dissolve in water. In particular, it is used for the creation of print supports when using FDM dual extruder machines. This offers users greater design freedom for parts with complex geometries, without affecting print quality. The more details and cantilevered parts the design has, the more supports the part will require in order to be manufactured. This guide will help you better understand the properties of this material, as well as its role in 3D printing in obtaining the best results in each manufacturing process.

Production and Characteristics of PVA in 3D Printing

On a technical level, PVA is part of the synthetic polymer family, with the particularity that it is biodegradable. It is created by polymerizing vinyl acetate, which is then hydrolyzed to obtain the material in filament form for 3D printing. It has a transparent to off-white appearance and is highly resistant to oil and grease. In addition to having very good adhesive properties similar to other thermoplastics such as PLA, CPE or Nylon, this material has a high tensile strength and flexibility. It is also odorless, non-toxic and, as mentioned, biodegradable, making it safe for humans, animals and the environment.

PVA is a soluble material used as printing support (photo credits: Ultimaker)

More specifically, it has a tensile elongation of 360% and a tensile strength of 22MPa. Depending on the humidity, PVA can also become very flexible and elastic, because water is like a plasticizer for PVA. PVA, which is actually brittle, fragile and tensile, becomes more and more elastic when moisture is added from the air or from water, and dissolves completely in water. Otherwise, it has a transparent to cream-colored appearance and is very resistant to oils and greases. It is easy to process in 3D printing because, among other things, it is non-toxic and actually odorless, although a slight odor may be produced during printing. However, for use in additive manufacturing, it is important to note the melting point of 230°C and especially the degeneration temperature of 200°C. At this temperature, PVA begins to carbonize, which can lead to black spots on the printed object.