When it comes keeping your filaments in optimal shape, one of the most critical factors to overcome is humidity. In general, plastics are prone to absorbing humidity when exposed, which leads contaminated plastic that lessen the quality and causes bubbles in your final 3D print. There are a number of ways to keep humidity from infiltrating your filaments, some are professional options, while others require a bit of imagination. But, the bottom line is that, in order to obtain the highest quality print possible, you must protect your filaments from the throes of humidity.
Ultimately, there are two vital components to a proper anti-humidity filament storage system, a sealed container and a desiccant, which is used to absorb the humidity in its surrounding environment. Most of the time, this desiccant is a simple silica gel, which can be regenerated in a oven at around 120°C. These two ingredients are key to keeping your filament safe and secure, whether you’re creating your own storage system DIY-style or looking into buying a professional one, such as the Bunker, a new smart filament cartridge system recently launched on Kickstarter by the Australia-based 3D printing company 3D Printing Systems.
There are essentially three ways to keep your filament from being ruined by humidity, the first of which is an extremely easy and affordable way, though it does get a bit messy. The amateur method is most convenient for those looking for a cheap way to workaround the humidity dilemma. Simply fill a sizable ziplock bag with 10 grams of silica gel and seal your filament spool inside, which will help protect against dust and humidity, but could still allow light to sneak through and alter the condition of your filament.
Although this method is among the most affordable, it’s far from a permanent fix. After a bit of time passes, moisture will begin to pass through the ziplock, which is why it’s vital that you change the silica gel once it turns green. Additionally, a vacuum bag would probably function even better than the ziplock, and is another option to experiment with.
If you wish to take things a step further, and have a bit of that maker and hacker spirit within you, you can build your own filament storage system. One designer uploaded a storage solution on Thingiverse, using 3D printing, a steel pipe, and an Ikea container to construct an pretty high quality storage system capable of holding eight spools.
Lastly, you can always buy a filament storage system like the Bunker, a smart filament storage system that aims to provide users with the optimal conditions and settings for you 3D printing materials.
“I run a 3D printing service, and need to have our printers running to the maximum throughput. if I get a failed print overnight then this is a delay on the customer's order, a delay on my output, a waste of money in filament and just a general frustration,” says Bruce Jackson, the creator of the Bunker. “So my secret to having reliable printers, is to reduce the amount of variables. The Filament Bunker reduces a lot of these variables, by keeping the dust and moisture away from my open spools, this improves the print quality. How often is it we open a brand new spool, print something and be amazed by the quality. Then use that same spool a few months later and have issues or inferior print quality.”
There are a number of other tricks to keep humidity from destroying the quality of your filament, you should always verify that the seal is in good state when you receive the spools, never buy filament that you plan not use for long time, change the silica gel each time you open the container, store your own stock of dry silica gel in a glass jar sealed, and last but not least, store your filament stock away from direct sunlight exposure and UV. Some filaments are more susceptible to humidity than others, and if not stored properly, will leave you with artifacts and poor quality prints. We talked with Alex Dick, the 3D printing innovator from Proto-pasta, one of the premier filament producers in the market, who provided us with some insight on the importance of keeping your filament dry.
“Dry Matte Fiber HTPLA, as delivered from Proto-pasta, can be printed very hot without oozing, resulting in strong/stiff composite parts. But, for materials like Matte Fiber HTPLA, which absorbs enough moisture to affect quality, it’s more critical to keep them dry. That being said, many printers leave the filament exposed and unsealed so things like the Bunker is a step in the right direction. If anything, hopefully it increase awareness. Until recently, moisture wasn't a consideration for me as a user. I'll think more about putting material in a sealed bin and creating some kind of cover for the filament on the back of my machines. All you need is a cover for the filament, a descant, and humidity measurement for sensitive materials,” said Dick.
In order to delve deeper into the effects of humidity on our filament, we will conduct testing with a Particle Electron, which is a battery powered cellular development kit connected to a DHT22 temperature/humidity sensor. The detecting range of this sensor is 5% RH - 99% RH, and -40°C - 80°C. The accuracy reaches up to 2% RH and 0.5°C. We will first experiment by sealing the subjected filament in a double ziplock bag, and after with 20 grams of silica gel. We then plan to share our findings with industry professionals to get their feedback on what our humidity testing is telling us, and from there, we can develop the optimal way to store and dehumidify 3D printing filaments.
At the end of the day, producers must ensure that their filament is equipped with enough desiccant and properly sealed with plastic that will not break during transportation. Once it makes it to the end-user however, it’s then up to us to take the proper steps and protect our materials from succumbing to humidity, leaving us with lower quality and more error-prone 3D prints.