Occasionally, 3D printing beginners purchase large quantities of filament without knowing how to properly dry and store it. Some filament-PLA, for example-is fairly forgiving. But other filaments, such as TPU and PETG, will create printing issues if they are not handled correctly.

In today's article, we're going to explain the importance of drying filament and provide three practical filament drying methods, so you can enjoy the best 3D printing quality possible.

Why Properly Drying Filament Is Essential

3D printer filament is hygroscopic. That means it absorbs moisture from the atmosphere like a sponge. In fact, minimizing moisture uptake is why most manufacturers vacuum seal new filament rolls and include a small packet of desiccant.

Extruding "wet" filament (it won't actually appear wet) causes excess moisture to vaporize, creating steam when passing through your 3D printer's heated nozzle. The steam creates tiny air pockets in the filament as it extrudes. Unfortunately, these pockets create common printing issues, such as:

• Uneven layers

• Poor bed adhesion

• Imperfect outer surfaces

• Deformed models (in rare cases)

• Failed prints

Avoiding these problems is why it's necessary to keep your 3D printer filament dry and to store it properly.

How To Check Your Filament

Regardless of what some sources might say, a visual inspection, a smell test, or a pull test often isn't enough to determine if your filament has been compromised.

Instead, we suggest using one of the following methods:

Weigh Your Filament Spool

You can use a small scale to weigh your filament before and after drying. If there is a variance after drying, you've removed moisture. You can use that post-drying weight as a rough baseline for other spools of the same type. But if you're drying the filament anyway, it might not be worth the additional trouble of weighing.

Use A Drybox With A Hygrometer

If you own a dry box with a hygrometer, you can place filament into the box, and after some time you should have a good read on the approximate mositure percentage. A reading below <=50% humidity on the hygrometer should indicate your filament is okay for printing. However, some makers have suggested <=30% to be the sweet spot. Some filament manufacturers recommend as low as 5-10% humidity. Because there are so many variables, it's often best to consult your filament manufacturer, or experiment until you find a level that works well for you.

Don't Bother Checking

If you haven't used a roll of 3D printing filament in a while, and it's been laying out exposed to the air, just put it in the dryer for a few hours. Don't even bother trying to check for moisture. A bit of extra drying won't hurt filament in most cases, and doing so lets you skip the annoying step of measuring moisture content.

How To Dry 3D Printer Filament?

Drying filament is a straightforward process. The hardest part is remaining patient during the drying time. That said, here are three ways we recommend drying your 3D printer filament.

1. Use a Filament Dryer

The first filament drying method is to use a specialized dryer. These user-friendly devices are inexpensive and can often dry more than one roll at a time. When choosing one, look for:

• Sufficient capacity to place your filament spools.

• Adjustable temperature and humidity settings.

• Practical functions like a built-in hygrometer and automatic shutoff.

• A price that fits your budget.

To dry your filament with a filament dryer, use this procedure:

1. Place your roll(s) of filament into the dryer.

2. Close and latch the lid.

3. Set the drying time, temperature, and humidity using the built-in controls.

4. Start the dryer, and wait until it completes its drying cycle. (Repeat steps 1-4 if needed)

5. Move the cooled and dried filament into airtight bags or containers. You may also use a small amount of desiccant to help maintain moisture levels.

2. Oven Drying

Filament dryers are our number one drying recommendation, but if you don't have access to one or don't want to purchase one, then you can use your household oven at a low temperature instead, just be sure to know how to dry filament in oven properly.

Choosing The Appropriate Temperature

Be careful when selecting an oven temperature for filament drying. Otherwise, you could melt your spool. All filaments have a glass transition temperature, or the temperature at which the filament changes from a solid into a liquid. You must stay below this threshold, otherwise your filament won't dry-it'll become a big messy blob. You can usually find this glass transition temperature on the filament manufacturer's website.

Filament that has a higher glass transition temperature-polycarbonate, for example-may not share a transition temperature with the spool it is wound on. Many manufacturers use spools made from ABS plastic, which can melt at higher temperatures. In those instances, you may need to remove the filament from the spool, abandon oven drying, or transfer the filament to a spool that can handle higher heat.

Recommended Oven Drying T emperatures

Below are a few suggested temperatures for oven-drying different filament types, so you can easily figure out what is the best temperature to dry filaments for each material.

• PLA/PLA+: 45 °C

• ABS/ASA: 75-80 °C

• PETG: 65 °C

• Nylon: 75-80 °C

• Flexible TPU: 50-60 °C

• Polycarbonate (PC): 120 °C

Next, let's learn how to dry 3D printer filaments using your oven.

1. Preheat the oven to the appropriate temperature.

2. Place the filament on a baking sheet.

3. Place the baking sheet in the oven and bake for 4-6 hours.

4. Remove the filament and allow it to cool.

5. Place cooled and dried filament into an airtight container or filament bag with desiccant before storing.

3. Food Dehydrator

If you own a food dehydrator, you can use it as a makeshift filament dryer. You'll need to clean it out before and after, and you'll want to remove any trays or grates that are used for food preparation.

Note: Mixing industrial plastics with food preparation equipment isn't always the best idea. If you're going to be drying a large amount of filament, we recommend spending the money on a dedicated filament dryer.

How to Dry Filament With a Food Dehydrator:

1. Remove any food-related items and clean out the dehydrator.

2. Place the filament spool(s) inside the machine.

3. Set the dehydrator's temperature to the lowest temperature setting using the filament chart above.

4. Allow the filament to dry for 4-6 hours. (nylon and polycarbonate may take up to 12 hours)

5. Remove the spool and allow it to cool.

6. Place cooled and dried filament into an airtight container or filament bag with a some desiccant for storing.

Proper Filament Storage

Besides drying wet filament for 3D printing, you'll also need to store it properly to prevent it from taking on moisture again. Here are a few ways to store filament so that it stays dry and is ready for your next project:

• Use an airtight container and keep it away from potential sources of humidity, such as leaky sinks and damp basements.

• Filament dry boxes or dedicated filament storage bags work well. You can even save the bags your filament comes in and reuse them if they are airtight.

• Place desiccant or absorbent moisture beads into your filament storage container.

As long as you dry and store your filament according to this guide and use a reliable 3D printer, your 3D prints should come out looking great. Additionally, if you're interested in upgrading your current 3D printer, we'd like to provide two recommendations:

AnkerMake M5 3D Printer

• The first 3D printer we'd like to recommend is the AnkerMake M5 3D Printer. It's a high-performance 3D printer with fantastic versatility. It supports a wide range of 1.75 mm filaments, including PLA, PETG/PET, ABS, TPU, PLA-CF, and PETG-CF, and offers flexibility for diverse printing projects. Equipped with an integrated AI camera and time-lapse video feature, M5 allows real-time monitoring and recording of the printing process. Plus, with impressive 0.1 mm precision, it provides exceptional print quality and detail. 

AnkerMake M5C 3D Printer

• Our AnkerMake M5C 3D Printer is another option. It's tailored for users with demanding requirements for both print quality and speed. It boasts high-speed printing capabilities up to 500 mm/s, which enables rapid project completion. Moreover, it offers a remarkable 0.1 mm precision and supports a wide range of materials, including PLA, PETG/PET, ABS, TPU, PLA-CF, PETG-CF, PA and PA-CF. Finally, M5C provides the convenience of remote control through the AnkerMake app, including one-click pause and stop functions, to enhance your efficiency. We know you'll love the outstanding detail and quality M5C gives your prints.

Some Safety Tips For Drying 3D Printing Filament

Since the filament drying process requires relatively high temperatures, it can create harmful gases or present a fire hazard. Therefore, when drying 3D printing filament, it's best to adhere to the following safety precautions:

• Monitor filament dryer temperatures to prevent filament from melting.

• Dry the filament in a place with adequate ventilation to prevent the accumulation of harmful gases.

• Keep the filament away from open flames.

• Periodically check in on the drying process for signs of danger.

• Allow your filament to cool completely before you store it.

Conclusion

Drying filament is an important part of the 3D printing process. With the right techniques and tools, you can create high-quality 3D prints. In drying filament for 3D printing, there are many methods available. Filament dryers, ovens, and food dehydrators are all proven methods that have brought a lot of success. But, proper filament storage and a focus on safety are also essential.

FAQ

How long does it take PLA to dry in the dryer?

The drying time of PLA filament depends on its moisture content. However, 4-6 hours is a good starting place. It's difficult to over-dry filament using the methods we've suggested, so don't be afraid to err on the side of more drying time rather than less.

You should note that most PLA filament remains print-stable even if exposed to open air for months. But, if your print quality is declining, drying your filament is a great first step to identifying the problem.

Does drying filament damage it?

Properly drying 3D printing filament will not cause damage. However, if the drying temperature is too high or the drying time is too long, the filament may become deformed or brittle.

These guidelines can help when you're drying your filament:

• Do not attempt to dry your filament past its melting point.

• Most filaments will only need 4-6 hours of dry time.

• After drying, seal filament in an airtight container and store properly.