Guide

Prusament PVB – our new transparent filament designed for easy chemical smoothing

We are excited to announce that we once again expand our Prusament portfolio, this time with 6 colors of new, unconventional material PVB. This type of filament is great for printing design models because the material is very easy to post-process with isopropyl alcohol (IPA). The surface of PVB prints can be smoothed out and parts can be easily glued together. Let’s take a look at the details!

Specification

PVB has similar mechanical and printing properties to PLA. However, thanks to its transparency and easy smoothing with IPA, this material is most suitable for the production of visual models, such as unconventional vases, jewelry, lamps, and other art pieces. The most ideal are models that should be printed with transparent filaments. It’s good to tweak various print settings, such as layer height, the number of perimeters, and infill density to make it look even better. Plus, we recommend using the vase mode in combination with a larger nozzle diameter.

Keep in mind that PVB is not the best option for printing mechanical parts. Its dimensional stability, tensile strength, and impact tenacity resembles CPE (and low-tier PETG) but its temperature resistance and layer-to-layer adhesion are similar to PLA.

 

Cons
Poor layer to layer adhesion (slightly worse than PLA)
Low temperature resistance
Hygroscopic filament (absorbs moisture)
Higher price

Our colors and price

PVB comes in six colors: Prusa Orange Transparent, Bright Green Transparent, Dark Blue Transparent, Light Yellow Transparent, Natural Transparent and Smoky Black Transparent. All colors are available on 500 g spools for 24.99 USD/EUR (VAT incl.). Plus, for the same price, we offer a box of samples that includes 25 g of each color available – this way you can try them all and find out which color is the best for you. We also prepared a set of test models for you!

To make printing with the 25 g samples easier, we recommend using this special sample holder that can be assembled using two 3D printed parts and an empty Prusament spool.

Printing with our new nozzles

With PVB comes a new 0.8mm nozzle! You can order it now for 8.46 USD / 6.99 EUR (VAT incl.) from our eshop. There’s a good reason for releasing PVB and larger nozzles simultaneously: It’s much easier and faster to print PVB models with vase mode and a 0.8mm nozzle. The walls will be more solid and more resistant to deformation caused by IPA smoothing. Models printed with 0.8mm nozzle and vase mode can be smoothed so well, they look almost like a glass.

PVB chemical smoothing

Before we start with how-to manuals, let’s sum up basic safety rules. IPA is slightly less toxic than other substances used for smoothing (acetone, chloroform, dichloromethane etc.) but it’s still an organic solvent. Always work in a well-ventilated environment and use gloves and other protective equipment (glasses, respirator). Do not pour used IPA into drains and waste pipes! IPA can be used multiple times. Once it loses its properties, contain it in a bottle and dispose of it as a dangerous substance (according to your local legislative rules).

The main advantage of PVB is chemical smoothing. Unlike other materials, PVB can be dissolved with IPA. This solvent is less toxic than other used chemicals (acetone etc.) and can be usually bought at your local hardware store. PVB smoothing can be done at home if you follow the safety rules mentioned above. Let’s take a look at the most common methods for smoothing PVB models:

  1. Smoothing station (Polymaker Polysher)
    An automatic smoothing station is a safest and fastest way to achieve a smooth, glossy surface on your prints. Simply put the model inside for 35-40 minutes and then let it dry for two hours. The main disadvantage is the high price of such stations.
  2. 15-30 minutes of washing in IPA bath
    Immersing a 3D-printed PVB object in IPA can lead to a perfectly smooth surface. However, this method has several disadvantages you should take into consideration: The print usually floats (depends on its infill and other factors) and the surface becomes somewhat soft and “slimey”. This means that it’s difficult to remove the model from the bath without disrupting the smooth surface. Also, it takes a long time for the model to dry completely. The washing itself takes 15-30 minutes and drying takes usually several days.
  3. Washing in IPA for short periods of time
    A good-looking surface finish can be also achieved with consecutive shorter washing times. Disadvantages are similar to the longer exposition, however, by immersing the model in IPA for a short time, it melts only on the surface, while inside it remains solid. Simply immerse the model in an IPA bath for 30 seconds, remove it and let it dry for at least 15 minutes. Repeat this process five times or more for good-looking results.
  4. Smoothing in IPA vapors
    We’ve shown you this method in our older article. Its main advantage is low IPA consumption and easy solvent and model manipulation. But you should keep in mind that surface smoothing might be uneven without proper air circulation inside the box and it usually takes a long time (dozens of minutes to few hours). The process is simple: Pour a small amount of IPA inside the smoothing box, place the model on an elevated metal platform inside and wait. Check the model regularly to see whether it’s not melted too much. Keep the box warm and ensure good air circulation inside to get the best results possible.
    If you don’t have any proper box and need to smooth small models, you can use an improvised method with kitchenware. Take a cylindrical glass, put a napkin soaked with IPA on the bottom and secure it properly. Printing a circular gadget with flexible filament might help. This will serve as a lid for your smoothing box. The bottom consists of a plate filled with water and an elevated (metal) platform in the middle. Put the model onto the elevated platform and put the glass onto it (bottom facing up). Let it work for 2-3 hours, however, don’t forget to check it regularly.
  5. Spraying IPA directly onto the surface
    This is basically the same method used in Polymaker Polysher. The main advantage is low IPA consumption, disadvantage comes with applying too much or too low IPA that might lead to uneven surface finish. IPA application and drying (at least 10 minutes) should be done at least five times.
  6. Using a regular brush
    This is by far the simplest method you can use. However, it comes with three main disadvantages: Using the brush usually takes a long time, the brush can leave marks on the surface, and with incorrect application, it may even leave bristles on the model. If you choose this method, apply IPA onto the model’s surface, then let the model dry for at least 30 minutes. Repeat if needed.

Tips and tricks for successful smoothing

  • Use at least 70% IPA. More diluted solvents might not work enough.
  • Prints should be placed on a non-adhesive platform (aluminum foil, metal plate, etc.). Other materials might stick to the surface too well (paper for example).
  • Long drying requires the object to be rotated regularly. In some cases, the model might stay soft for a long time, stick to the surface or deform due to non-ventilated parts.
  • Drying too fast or too slow causes bubbles of air to manifest inside the print. The best option is to dry it at room temperature and rotate it regularly.
  • Long exposition leads to deformation, loss of details, and long drying times (a week or more).
  • PVB dissolved with IPA should not come in contact with water. Wait at least 3 days before washing the model. Water leaves white marks on the dissolved (soft) surface and in some cases it can disrupt the internal structure. Dissolved PVB might also leave white marks on the smoothing container surface if it’s washed with water.

Keep the filament dry

PVB is very prone to absorbing moisture. Always put the spool back inside the bag with silica gel or let it dry for 4 hours at 60 °C before printing!

Typical applications for PVB

 

Do you want to learn more about PVB mechanical properties? Don’t forget to check our material table. We hope our new PVB Prusament will expand your 3D-printing horizons and you will enjoy using it! As always, we’re looking forward to seeing your great ideas and original models!

Happy printing!



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