January 14, 2021
pva filament guide

PVA Filament: The Complete 3D Printing Guide

PVA filament (Polyvinyl Alcohol) is perhaps best known for being mistaken for Polyvinyl Acetate (white glue), as both use the same acronym. Perhaps its second most defining feature then, is that it’s entirely water soluble, and non-toxic. As a result, it is often used as a soluble support for PLA filament.

These two properties have ensured that PVA is used extensively not only within the realm of 3D printing filament, but also in almost every facet of modern life.

History of PVA in 3D Printing

PVA was first discovered in 1924 by German Nobel Laureate Dr Hermann Staudinger. Japan began PVA research, resulting in “Synthetic Fiber No. 1” being produced in 1939, under Professor Ichiro Sakurada of Kyoto Imperial University. The research was then picked up by the Kuralon company, becoming the first company in the world to mass-produce and commercialize PVA fibers in 1950.

Although PVA filament could have been produced from the inception of 3D printing, it struggled to find a use until the adoption of multi-material 3D printing in 2006. Rather than just being able to print an object that will ultimately degrade in the open air, suddenly, the opportunity arose for PVA to be used in its now defining role, as a water-soluble support material.

Two 3D printed hearts, one with PVA support material, the other with the supports removed.
PVA support material, before and after being removed.

PVA 3D printing properties

PVA is entirely water soluble, odorless, colorless, soft, biodegradable, and non-toxic at low concentrations.

Within 3D printing, PVA is most known for being a support material for dual extruder 3D printers. Most typically it is used in combination with PLA, not only because of PLA’s popularity, but also because both have very similar extruding temperatures.

PVA 3D printing parameters & temperatures

With the exception of part-cooling fans, which are required, PVA does not need any additional equipment for 3D printing, however, some optional hardware may make life a little easier.

  • PEI sheets or painters tape build surface are recommended
  • A heated print bed is optional but recommended. If used, it should be set to 45⁰C-60⁰C, or a temperature specific for your filament.
  • An ooze shield is optional, but recommended. 
  • PVA’s extruding temperature ranges between 185⁰C-200⁰C. Check your PVA filament for specifics.
  • Adjust your 3D slicer infill settings to make your filament go further. Use a low infill percentage throughout your PVA support structure, and then using a higher percentage only where it contacts the print.

Advantages and Disadvantages of 3D printing PVA

Benefits of PVA Filament

Advantages and dissadvantages infographic

Water soluble: Being entirely water soluble allows PVA to be used as a dissolvable support material. Dissolving PVA leaves no blemishes on the final print, as no force is used to remove the supports.

Biodegradable & environmentally friendly: PVA will completely biodegrade, and is harmless to the environment in low concentrations.

Disadvantages of PVA filament

PVA filament doesn’t require any special steps to get the best results. However, PVA can have a smaller margin for error than more typical filaments. With that in mind, here are some common pitfalls to avoid:

Requires careful storage: Being entirely water-soluble means that the filament can have strong reactions to any form of moisture, even in the air. If not stored correctly, or if the filament contacts moisture before printing, then the final prints can bubble or crack, degrading their final quality and strength.

Expensive: PVA is expensive, easily costing two or three times as much as ABS or PLA filament. 

Clogging and Oozing: Although not considered an especially challenging material to work with, PVA does have a smaller margin for error when compared to PLA. If the printhead temperature is set too high, or even if the printhead is left idling for too long, then PVA will either ooze or degrade and essentially cook inside the nozzle, clogging it. Even with your temperature set up correctly, PVA is still prone to oozing, especially between prints. To avoid this, we recommend using an ooze shield, and being vigilant with cooling down your printer nozzle between prints. We also recommend removing any unused PVA from your printer when not in use to limit its exposure to potentially humid air.

Best PVA Filaments

We recommend the following PVA filaments:

Best PVA 3D printers

As it is rarely used on its own, only dual extruder printers can effectively 3D print PVA. These printers have two print heads, and can be loaded up with two different materials, such as PLA and PVA. We recommend the best dual extruder 3D printers in our separate ranking below:

PVA Applications

PVA filament’s main application is that of a water-soluble support material for dual extruder printers.  Being both non-toxic, soft, and easily dissolved in water, it is ideal as a support filament, able to be easily removed without blemishing the final print.

PVA can also support complex shapes, or fill concave or hollow objects, allowing these opbjects to be easily printed and supported where breakaway supports would struggle.

Outside of 3D printing, PVA’s non-toxic properties allow it to be used in many of the plastic household objects we take for granted. Laundry capsules such as Tide pods, disposable contact lenses, coatings for pills and tablets, fishing bait-bags, food packaging and biodegradable plastic bags are all common uses for PVA.

Laundry detergent capules, made using PVA
Laundry Capsules, a common use of PVA.

How to Store PVA Filament

It is important to store your PVA correctly to ensure that it comes into as little contact with moisure as possible before printing. Dry PVA will give you the best printing results, and will be far less likely to ooze or clog in your printhead.

Ensure that it is always stored in an air-tight container: Most PVA will be delivered in a sealed or air-tight disposable bag, a bag that will predictably become a lot less airtight once opened. Ensure that before you open these bags, that you have an air-tight container ready to store your filament.

We recommend the following filament storage:

Recovering Wet PVA

If your PVA does become wet the spool isn’t necessarily ruined, as there are ways to recover it.

Assuming that your spool hasn’t completely dissolved like cotton candy, your first clue as to whether your PVA has absorbed too much water will be a soft and sticky texture, or the filament appearing warped. Your next clue will be a hissing or steaming printhead while in operation, and your final clue will unfortunately be a poor-quality print.

Recovering your PVA is luckily as simple as using a commercially available dehydrator. Failing that, your PVA can be dehydrated by heating it. We recommend heating it to between 45⁰C-55⁰C for two hours on a heated build-plate, or 113⁰F-131⁰F in an oven.  Exact drying times and temperatures will vary depending on your brand, and how wet your filament is, so expect a measure of trial and error when trying to dehydrate your PVA.

Alternatively, you can purchase a filament dryer. These are specially designed to dry your filament and replenish its best 3D printing properties. We recommend the following:

A spool of PVA filament in a microwave
What’s for dinner tonight? PVA and fries?

Making PVA Filament

Polyvinyl Alcohol begins life as Polyvinyl Acetate (white glue). It is first dissolved in alcohol, usually methanol or ethanol, before being treated with an alkaline catalyst such as sodium hydroxide in a process fittingly called “Alcoholysis,” a specific type of hydrolysis reaction. Once completed, the “acetate” groups are removed from the molecule, resulting in Polyvinyl Alcohol.

Raw PVA usually comes in the form of solid pellets or a solution. Once thoroughly dried out, it can be extruded and rolled into a spool, ready for 3D printing.    

PVA fillament pellets
Raw PVA formed into small pellets

Is PVA really so good for the environment?

PVA will completely biodegrade, with PVA and starch blends theorized to take just over 12 years to degrade by 70%. By comparison, PLA would take 80 years to completely degrade if left in an open environment. 

Its low toxicity also means that water solutions can be safely disposed of down the sink, with the solution easily filtered out by treatment plants. Even untreated water concentrations of less than 5% are safe for fish. 

Additionally, unlike other plastics, PVA has no risk of producing micro-plastics. As it biodegrades it breaks down into monomers, which in turn decompose into nutrients and safely re-enters the environment.

The result is a zero-waste product which, if properly managed, has no long-term environmental impact. A truly guilt-free 3D printing filament.