One way to drastically improve the quality and consistency of your 3D prints is to make sure that your filament is very dry as you 3D print it.
3D printer filaments tend to be hygroscopic, meaning they absorb water. Unfortunately, this water can wreak havoc once the filament is in your hot end and superheated to upwards of 200 degrees C!
To keep your filament dry, you must store it properly – and in some cases, you may wish to invest in a filament dryer to both keep your filaments dry and to dry out any filament that has absorbed some moisture.
The basic idea of a filament dryer is quite simple: it uses a combination of heat and airflow to evaporate the moisture from your filament.
Best Filament Dryer: 4 Picks
SUNLU Filament Dryer
First up on our list of commercial filament dryers is the SUNLU filament dryer. It’s the most robust filament dryer on our list and that’s why it comes number one.
You can use it both for keeping filament dry when in storage and also to print from directly. It works by letting you set a temperature you wish the inside of the box to be at, and the box will rotate your spool of filament to make sure the heat is distributed evenly and there is good airflow over all parts of the filament.
It works with all filament sizes, so whether you use Ultimaker or Prusa-style printers, you’ll be able to use the filament dryer with ease.
The best part about the SUNLU is that you can use it as a spool holder as well, so even if your printer is not running and you have a spool of filament attached to it, you’ll be fine.
However, the main drawback of this filament dryer is the steep price point. You may want to think twice before dropping so much money on a filament dryer.
It also only goes up to 55 degrees C, so if you need to dry nylon filament(which needs to be heated to around 70 degrees), you’re out of luck.
We’ll talk about a DIY option below in case you balked at the idea of spending so much on a filament dryer!
Polymaker Polybox Filament Storage Box and Dryer
The Polymaker Polybox is an offering from a very reputed company. Polymaker filaments are some of the best in the industry, so it’s no surprise that they’ve come up with the polybox as a solution to dry and store filament.
The Polybox is an industrial solution that can store one large 3kg spool or two small 1kg spools. There are 6 filament outlets so you can position the box in a number of ways that works best for placing the box wherever convenient next to your 3D printer.
The drying mechanism is two large bags of dessicant that fit under the box. The dessicant absorbs any moisture within the container, and if you keep the container closed, very little extra moisture will then get it.
Dessicant is a very reliable way to dry filament because that’s how most filament spools ship from the manufacturers!
There’s also a built in hygro-thermometer which shows you how warm and how humid the inside of the box is. If you’re looking for high-precision printing, then this is the tool for you.
The filament rolls on high quality bearings and steel rollers that keep the filament spool spinning and feeding filament as your printer demands.
The only downside of this system is that there is no heating element, so if you need to “cook” moisture out of a filament, then this will not be effective.
Self-contained inline filament dryer
The last option on our list is the most expensive of the lot and is the most robust. However, the main difference between this and the other filament dryers that we’ve listed is that this is an inline filament dryer, meaning it dries the filament immediately before it is fed into the printer.
The other dryers that we’ve listed here all dry the filament continuously by keeping the whole spool dry.
This is a middle device that you’d place between the 3D printer and the filament spool. It’s actually the most effective solution of the lot since it focuses on the exact length of filament that is being fed into your printer.
Also, it only works with 1.75mm filament, which is fine for most folks who are into 3D printing, but if you use Ultimaker, you are out of luck.
Good ol’ fashioned food dehydrator(NESCO Gardenmaster)
There’s no question that dehydrators are the most effective ways of removing moisture, since food generally contains a lot of moisture!
This dehydrator can also do a max of 165 degrees F, which is around 70 C, the amount you’d need to dry a filament like nylon.
To use a dehydrator effective, you’ll have to cut away the netting from between the layers – so your dehydrator is basically exclusive for filament.
You could still use it for one layer of food, but you may not wish to mix food and filament!
Dry your filament at home using an oven
In case you’re not in the mood to drop the money on a filament dryer, you can probably use your oven to dry filament if it has very accurate temperature control under 100 degrees C.
The idea is to heat the filament to below the glass transition temperature, after which the dimensional accuracy and molecular structure will get messed up.
Place your filament on a tray in the oven and raise the temperature to around 50 degrees C.
Leave the filament in the oven for about 30 to 60 minutes and remove it.
Make sure you are using an oven thermometer to maintain the temperature. If it gets too hot, your filament will get ruined!
Dry your filament at home using a desiccant
Another DIY approach to drying filament is to place it in an airtight box and fill the box with a desiccant like silica gel or uncooked rice.
Normally, a small packet of desiccant will do the trick, but you may need to dump in a lot and really let it sit if the filament was left out in a humid area for too long.
Conclusion
Drying your filament before printing is a way to really improve your 3D prints significantly. If you’re running into issues like bubbles or gaps in layers, it may be because your filament has too much moisture and the water is expanding and evaporating as the filament goes through the hot end.
This will help you get an edge in your 3D printing and really improve your results.
Good luck!
