When do you need to print with support materials?
The big advantage of 3D printing is that it enables you to print very complex models, that are hard to produce with other techniques. For instance, think of printing an overhang. Because 3D printed parts are built up out of layers, you always need a layer underneath to build upon. Depending on the complexity of the 3D model, it could therefore be necessary to work with supporting structures. Underneath we will explain the possibilities.
An FDM 3D printer can -in most cases- print an overhang with an angle under 45° without needing any support. A tip when doing this: reduce the layer height, for instance from 0.2 to 0.1mm. The printer now produces twice as many layers, enabling the printer to take smaller steps when creating an overhang. For angles bigger than 45°, it’s advisable to support the 3D model. This can be done in three ways:
- Supporting with the original material
- Supporting with PVA filament
- Supporting with PVA+ filament
Supporting with the original material
We’re starting with the easiest and fastest way to support your 3D print. Moreover, it’s the only option when you’re printing with one extruder. With this method, the needed support is printed of the same material as the model. This method works easy; you only need one material. A slicing software package, like Simplify3D, can generate these support structures. Note that it’s important to not use too much support material, as supporting structures of the same material are harder to remove from the model than the other options.
Supporting with PVA filament
There are special support filaments available that are completely soluble, PVA is one of them. To be able to print with PVA, you require a 3D printer with a double extruder.
PVA stands for polyvinyl alcohol and is a soft and biodegradable polymer that is very sensitive to moisture. When PVA is exposed to water, it will dissolve. Therefore, it’s perfect as support material for 3D printing. After printing, the filament can easily be removed by dissolving it in cold or lukewarm water. PVA is often used in combination with PLA filament, but is now also applied more and more to other filaments like PET-G. Besides that, there are various new modifications that enable using PVA with higher temperatures. We’re then talking about for instance PVA+.
Supporting with PVA+ filament
Previously, HIPS was mostly used as a support material for printing in ABS. With the arrival of PVA+, HIPS is used a lot less. The reason for this change is that HIPS needs to be dissolved in limonene. This is a hard to obtain, chemical substance. Therefore, HIPS is often replaced by PVA+ (modified PVA), a filament that is easily soluble in water – just like PVA. At this moment, PVA+ is tested for its suitability to be combined with all other filaments. For PVA+, it’s also required to use a double extruder.
The big advantage of printing with support material is that it’s easily removed without leaving parts behind or damaging the 3D model. A disadvantage is that support filaments are often more expensive than the base filament and that it can only be printed on a 3D printer with a double extruder, like the dddrop EVO Twin.