PVA, or polyvinyl alcohol, is a widely used material in the 3D printing industry due to its ability to dissolve in water. In particular, it is used for the creation of print media when using dual FDM extruder machines. This offers users greater design freedom for parts with complex geometries, without compromising print quality. The more details and overhanging parts the design has, the more supports the part will require to be manufactured. This guide will help you better understand the properties of this material, as well as its role in 3D printing in order to obtain the best results in each manufacturing process.
Characteristics of PVA in 3D Printing
At a technical level, PVA is part of the family of synthetic polymers, with the particularity that it is biodegradable. It is created by polymerizing vinyl acetate, which is then hydrolyzed to obtain the material in the form of a filament 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 high tensile strength and flexibility. For good substrate results, PVA requires preheating the print pad to 45-60°C and bringing the extruder to 180-200°C. It’s also odorless, non-toxic, and, as mentioned, biodegradable, making it safe for humans, animals, and the environment.
Among its main advantages is, as mentioned, its ability to dissolve. In addition to this, the most remarkable thing is that it only needs water to remove the support material, that is, it does not require solvents with more complex components. Also, it does not require any additional hardware. However, some of the disadvantages of PVA are also worth mentioning, although they are generally applicable to other soluble materials. One of them is the high sensitivity to humidity, which can directly affect the material. So that its properties are not altered, it will be necessary to keep it in areas where the air is very controlled. PVA is also more likely to clog if the nozzle is left hot when not extruding. Added to this is the fact that many users consider it an expensive filament for what it is, since in the end it is not used in the final parts that are printed, but rather dissolves in post-processing.
Usage and Applications
As a soluble material, PVA is ideal as a complement in the manufacture of parts with complex geometries, as well as internal cavities, conceptual models and molds. 3D printed supports offer improved surface quality and also allow the part to be oriented to optimize its mechanical properties. An important point to take into account when working with this material is the configuration of the extruders. Cooling the PVA hotend while it is idle will prevent the weeping and clogging mentioned above. Also, it is recommended to set the top support gap distance to 0 layers for the most optimal surface finish. Since the supports will dissolve, it doesn’t matter if they stick to the final part during the manufacturing process.
By allowing the 3D printing of all kinds of pieces, no matter how complex the design, PVA is a material widely used in the art world to create decorative models. However, it is not the only sector that is taking advantage of this filament. Even the most advanced industries that work with FDM technology to create tools or prototypes are also increasingly integrating soluble materials to create supports. Among the companies that offer PVA filaments we can find Ultimaker, eSun, MatterHackers or Polymaker, among many others. If you want to know more about other 3D printing filaments, you can consult our guide HERE.
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*Cover photo credits: Zortrax