3D Printing with BVOH Advanced Water-Soluble Support Material

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09 Oct, 2023

Image credit: 3dgence

Image credit: 3dgence

Large-format 3D printers open up new AM possibilities, but extra-large prints require extra-sturdy supports.

BigRep is best known for its large-format 3D printers like the versatile BigRep ONE and production-ready BigRep PRO. Over the years, its sizable machines have been used in areas like construction and industrial casting. In addition to its large-scale 3D printers, BigRep also offers a range of 3D printing materials ready for XXL applications. These range from PLA to PA12 to concrete. Needless to say, the company’s filaments are available in very large spools suitable for continuous large-format printing.

Since all BigRep 3D printers now have the option of dual extrusion, the company also offers a dedicated support material. This allows users to use a build material for their parts and a separate, dedicated support material for the temporary scaffolds around the parts. BigRep’s BVOH support material is sturdy, adheres to most materials, and prints as easily as PLA. And because the material is water-soluble, the printed supports can be washed away in tap water.

This article looks at how BVOH can improve large-format additive manufacturing on BigRep FFF machines like the BigRep ONE.

What is BVOH 3D printing filament?

BVOH (Butenediol vinyl alcohol co-polymer) is a water-soluble support material. That means it is designed to print temporary support structures that can be dissolved in tap water — cold or warm.

Many 3D printer users prefer water-soluble supports because removal is faster, easier, and doesn’t leave unsightly marks. Supports printed in an insoluble material typically have to be removed with a knife, which creates a surface blemish.

Overall, BVOH behaves a lot like PVA, another common support material. However, BVOH offers superior adhesion to build materials like ABS and is less likely to cause nozzle clogs. It also dissolves at a faster rate, making the support removal process as short as possible.

Why use BigRep BVOH filament?

BigRep BVOH filament is compatible with all BigRep large-scale 3D printers (and other open-material FFF printers with dual extruders). By 3D printing support structures in BVOH, the support removal process is drastically shortened.

Although BVOH works best with PLA — it has similar temperature requirements and good natural adhesion to it — it is compatible with all BigRep filaments. By contrast, some water-soluble materials on the market are not compatible with certain build materials such as ABS. Naturally, BigRep BVOH is especially practical for large-format 3D printing, as it is available in very large spools: available sizes include 0.75 kg, 2.5 kg, and 4.5 kg (8 kg upon request).

Users of BigRep’s industrial 3D printers will find it easy to incorporate BVOH into their workflow. This is because BigRep has developed a preconfigured BVOH print profile for its BLADE slicing software.

Benefits of 3D printing BigRep BVOH

There are several benefits to 3D printing BigRep BVOH over other water-soluble support materials like PVA. These include superior adhesion to build materials — even tricky materials like ABS — and ultra-short dissolving times. The fastest speeds can be achieved with warm water, but cold water also works.

So what makes BigRep BVOH stand out over other BVOH filaments on the market? In addition to the range of spool sizes, BigRep BVOH has been optimized for improved melt flow to prevent clogging and has a slightly lower print temperature than some comparable products.

Unique advantages of BigRep BVOH:

  • Improved melt flow to prevent clogging

  • Adequate tensile strength (34 MPa) to support large prints

  • Wide material and machine compatibility

  • Available in large spool sizes: 0.75 kg, 2.5 kg, and 4.5 kg (8 kg upon request)

What to look out for when 3D printing BigRep BVOH

Newcomers to dual extrusion additive manufacturing may encounter some challenges when 3D printing BVOH. Although the material prints well at moderate temperatures, it has some quirks that require care and attention.

The most common issue with any water-soluble support material is nozzle clogging. And while BigRep has developed a highly clog-resistant BVOH formulation, users should still take steps to minimize clogging by performing regular nozzle cleaning. One option is to perform a cold pull with a dedicated cleaning filament; another is to use a long needle to manually clear out debris.

Finally, users of standard and professional 3D printers may find that BigRep BVOH adheres better to the build surface with the help of an adhesive coating like Magigoo glue stick.

Material properties

BigRep BVOH filament has a low melting temperature of 175 °C. This makes it easy to print: the required nozzle temperature is 190–210 °C, with a bed temperature of 60 °C. These print settings are similar to those for PLA.

Since the purpose of support material is to hold up heavy structures, it also needs to be strong. BigRep BVOH has a fairly high tensile strength of 34 MPa, which is slightly higher than ABS.

The most important property of BVOH is its solubility in water. Support structures can be washed away in cool or warm water, although warm water helps speed up the process. However, keep in mind that the material’s solubility can make it vulnerable to humidity.

Best practices for handling and storing BigRep BVOH

Like other soluble support materials, BigRep BVOH is highly hygroscopic. This means it absorbs moisture easily, which can become an issue in humid environments.

Because of its hygroscopic nature, BVOH should always be stored in dry conditions at a temperature of 15–25 °C. With a humidity of just 0.01%, the BigRep SHIELD filament dry cabinet is an ideal form of storage, holding up to 60 kg of filament. For non-industrial users, a sealed container with a desiccant should be the bare minimum.

Drying out BVOH filament before use can also lead to better printing results and prolonged printer life. BigRep recommends drying the filament at 60 °C in a hot air dryer or vacuum oven for four to 16 hours.

Use cases

BigRep BVOH filament can be used for any build that requires support structures. Suitable parts include those with overhanging areas that cannot support themselves.

Water-soluble support material like BVOH is especially useful for parts that have internal or otherwise inaccessible overhangs. This is because cavities in the part can be easily filled with water to remove soluble internal supports. Conversely, it is not always possible to reach into a cavity to remove insoluble supports with a knife.

BigRep BVOH advanced water-soluble support filament is available to order via the BigRep HUB online store.