Exploring Soluble Support Materials for 3D Printing

Support removal can be an annoying part of post-processing in 3D printing. However, it does not have to be. If you have a dual-extruder 3D FDM 3D printer or any other process that allows multi-material printing, you can take advantage of soluble support materials. As their name suggests, soluble support is a material that can be used as for support structures in 3D printing and is soluble, whether in water, a chemical agent or organic agents. But what materials are out there? Find out in our list of some of the most common soluble support materials for FDM 3D printing (though many companies offer their own versions as well), separated by the medium in which they dissolve.

Water-Soluble Materials

PVA

Polyvinyl Alcohol (PVA), along with HIPS, is one of the most popular soluble support materials for intricate structures in FDM 3D printing. As would be expected, PVA’s most notable benefit lies in its water solubility, allowing for effortless removal of these supports and eliminating the necessity for harsh chemicals or time-consuming post-processing. Furthermore, PVA’s water solubility not only streamlines the printing process but also enhances design flexibility, enabling the production of more complex geometries in parts. Its compatibility with various filaments, such as PLA and Nylon, broadens its use, allowing for more visually appealing models and durable prototypes. This material operates within a temperature range of 45-60 °C, rendering a heated bed optional and eliminating the need for an enclosure. Additionally, the printing temperature for PVA falls in the range of 185-200 °C, and no special hotend is required, further emphasizing its user-friendly printing process. Despite challenges like PVA’s moisture sensitivity which calls for proper storage, PVA’s positive features, including transparency, biodegradability, non-toxicity, and ease of dissolving, establish it as a highly beneficial material for molds, decorative objects, and elaborate designs.

BVOH

Another water-soluble material used for support structures in FDM 3D printing is BVOH (Butenediol vinyl alcohol copolymer). It is particularly advantageous in cases where traditional substrates may be difficult to remove or fail to deliver the desired result. In fact, BVOH makes it very easy to remove substrates. Once you’ve printed a 3D object, all you have to do is immerse it in hot water for the support to dissolve completely, 100%. BVOH is practical for printing prototypes, such as small models and those with hard-to-reach spaces for removing supports. The material is also suitable for fine details, jewelry, decorations and complex structures. It imposes no limitations on object shapes during design. What’s more, BVOH is environmentally friendly and can often be disposed of down the drain. It can be printed on a variety of materials, including PLA, ABS, PETG, ASA and elastomeric filaments. To preserve its quality, it is advisable to protect it from humidity, light and UV rays by storing it in a dry place or using it quickly.

Aquasys 120

Aquasys 120, developed by Infinite Material Solutions, marks a breakthrough in the field of support materials for 3D printing. Its special formulation, which combines a water-soluble polymer with a polysaccharide called trehalose, ensures high thermal stability while preserving optimum flexibility. Aquasys 120’s solubility means it dissolves twice as fast as PVA at room temperature, and up to six times faster in water heated to around 80 degrees. Its versatility is reflected in its compatibility with various materials such as PLA, ABS, CPE, ABS, TPU, PC-ABS, PP and PETG, making it one of the most adaptable soluble support materials available on the 3D printing market. But it’s not the only alternative. Aquasys 180 also sets an unrivalled benchmark as an advanced and highly compatible support material. It is water-soluble and compatible with advanced high-temperature materials such as PEEK, PEKK, PEI and PPSU.

Organic Solvent-Soluble Materials

HIPS, a Thermoplastic Polymer for Support Structures

HIPS or “High Impact Polystyrene” is a thermoplastic polymer that is made from a blend of polystyrene and polybutadiene rubber. It is frequently used as a support material in FDM printing. Its main characteristic is its high solubility, which distinguishes it from other soluble support materials and allows it to dissolve easily in organic solvents. This means that no tools are required to separate the printed part from the support material. A user must simply immerse the part in the solution. In addition to its solubility, HIPS offers other advantages, such as heat resistance and translucency, making the printing process easier by allowing the user to see through the material. However, despite these advantageous properties, it has a number of drawbacks, such as the risk of discoloration, the production of toxic fumes during printing, and poor resistance to low temperatures.

PVB

Complex objects or those requiring internal supports benefit from PVB as a printing support material. Its solubility in solvent makes post-printing support removal a breeze. PVB’s chemical interaction with agents like isopropyl alcohol (IPA) enhances bonding and smoothing in the post-treatment phase of printing. Moreover, its compatibility with diverse materials such as PETG and nylon makes it highly versatile.

ATP-Based Polymers

As soluble in alkaline solutions, ATP-based polymers (acrylate terpolymers) are ideally suited for 3D printing support structures. Unlike other materials, they are not susceptible to dissolution upon contact with water; instead, they require an alkaline pH liquid, making them less vulnerable to humidity compared to PVA. Despite their increased resistance to ambient humidity, it’s crucial to store the filament spool away from direct sunlight and in a cool place. ATP-based support materials are compatible with ABS and ASA, among other materials, though specific compatibility may vary by manufacturer. Typically, manufacturers provide comprehensive information about compatible materials and guidance on printing parameters. Post-printing, the support structures can be dissolved by adding an activator to the alkaline liquid – often provided with the filament. A typical example of an ATP-based support material is Zortrax’s Z-Support ATP, which comes with the activator.

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