Best Ways To Store Your 3D Printing Filament

Moisture and humidity. These words send shivers down the spines of 3D printing filament worldwide. The very mention of it could mean your 3D models looking more like The Walking Dead as each day passes. And yes, I still see images of people leaving their filament out in the open, bare to the elements. Keeping your filament dry results in high 3D print quality, increased accuracy, as well as many other benefits.  In this article, I’ll be giving you some of the best ways to store your 3D printing filament, enjoy.

Why should I protect my filament?

It’s a very understandable question. After all, it’s plastic, it shouldn’t be able to absorb water. However, most thermoplastics used in 3D printing are hygroscopic, so they absorb water from the air if left unprotected. This means that simply leaving your filaments out in the open can result in poor-quality prints.

Nylon filament was harmed during this shot. via Instructables

The resulting effects on your filament aren’t pretty either, as here are some of the things that can happen to your filament once it absorbs moisture:

  • Increased brittleness
  • Filament degradation
  • Diameter augmentation
  • Filament bubbling / hissing steam at the hot-end
  • Higher temperature needed for extrusion
  • Broken filament

Some filament types are affected worse than others, for example, nylons are bad as they can absorb moisture after just 18 hours when out in the open. PVA, even worse, as it is used for support structures whereby afterwards it can dissolve in water. PLA and ABS can also absorb moisture (PLA more than ABS). Not only can your filament be affected, but your 3D printer too, as “swollen PLA filament can jam up the printer’s hot end and even require it to be replaced,” Clinton Freeman, RepRage.

Vacuum Bags – Use Them

You could buy an expensive plastic casing for your individual spools, or build an anti-humidity box on your roof to protect your filament from moisture, or, you can just buy a regular vacuum-sealed bag. You know, the ones you see on infomercials to keep all your winter clothes in order to save space in your home. Why use vacuum-sealed bags? Well they keep all types of moisture, odors, mildew and bugs away from your precious filament.

Make your vacuum cleaner useful again. via RepRap

Remember: these aren’t Ziploc bags (bags that you simply seal at the top), as those don’t always get out all of the moisture. Try buy bags that have an opening for your vacuum cleaner to make sure all that life-saving oxygen is removed from the bag.

Silica Gel – Not Just For Shoes

If you’re using PLA filament, silica gel packs must become your best friend. They might even come included when you buy some new filament, so you’re going to want to hold onto those. Why? Well, as mentioned above, PLA absorbs much more water than ABS. Don’t get me wrong, though, both still absorb water so use these packs for both ABS and PLA.

Blue means dry, purple, not so much. via forums.vr-zone.com
Blue means dry, purple, not so much. via forums.vr-zone.com

Silica gel packs come in all different shapes and sizes, such as these, which can be re-used if you dry them in an oven. However, these, as well as other packs like these, aren’t always the best as you can’t tell when they have become saturated. If you want to get serious with drying out your filament, then silica gel packs with moisture saturation indicators might be a better bet for you. These change color from yellow/orange to green or blue (depending on ambient moisture level). Simply place the gel packs into sealable Ziploc bags, Tupperware, or anything else that won’t let air get inside.

In the end, though, keeping your filament dry using silica gel is a neat and easy method for keeping your filament dry. Many people always ask if rice is a suitable replacement. It’s not bad, but it’s definitely not as good as using silica gel packs.

Use your filament – often

It’s great that filament comes in all different types and sizes. However, keeping too many and forgetting to use all of it, or simply not using the ones you have, is not the best idea if the filament is kept in an open area for long periods of time.

With great filament comes great responsibility. via Thingiverse
With great filament comes great responsibility. via Thingiverse

Be careful, keeping filament for over 12 months can lead to moisture absorption, depending on the filament. The best thing to do would be to buy only what you need, and make sure to use it all within a few weeks/months.

Bonus Tips:

Litmus, more than just for science experiments.
Litmus, more than just for science experiments. via Google Groups
  • Use litmus strips in order to indicate humidity – a quick way instead of using color changing desiccants
  • Always remove your filament when you finished printing
  • You can always 3D print your own spool holder to protect the filament from moisture
  • Make your own “dry box” from various sources on the internet
  • Dehumidifiers work well – just plug it in overnight when it says “wet” and you should be good to go again

You can’t make an omelette without cracking a few eggs, but 3D printing isn’t your typical breakfast, and using low-quality filament shouldn’t be an excuse for an average 3D print job. The tips used above, whether used on their own or combined with others on the list, will definitely help you with producing amazing, high-quality 3D prints. Some may sound a little extreme, but in the end it will help save time, money and tables from being flipped in frustration. You could even produce your own filament whenever you need if wanted to, but just remember that your filament is precious. If you look after it, it will look after your 3D printing. Do you have any extra tips that I forgot to mention? Let us know in the comments section below.