3D printing is an amazing technology that allows anyone to create complex objects right in their own home. However, one of the biggest challenges with 3D printing is dealing with filament that has absorbed moisture. Wet filament can cause a variety of print quality issues from stringing and popping to weak layer adhesion. This is why having a filament dryer is absolutely essential for flawless 3D prints.
In this guide, we’ll cover everything you need to know about picking the right filament dryer, from different types of dryers to key features and top recommendations. With the best filament dryer for your needs, you’ll be able to revive even the most moist filament and get perfect first layer adhesion and strength on every print.
Why You Need a Filament Dryer
Most 3D printing filaments like ABS, PLA, PETG, and Nylon are hygroscopic, meaning they absorb moisture from the air over time. This is especially true if you live in a humid climate. When filament absorbs too much moisture it becomes brittle and stringy, which leads to a variety of print quality issues:
- Poor layer adhesion
- Weak parts
- Strings and blobs
- Bubbles and popping sounds during printing
- Discoloration
- Warping
Even brand new sealed filament usually contains some moisture, so drying before printing is always a good idea to get the best results.
Filament that is exposed to air when you have an open spool sitting on your printer will absorb ambient humidity. PLA can absorb up to 1% of its weight in moisture, which doesn’t sound like much but is enough to cause major print problems.
That’s why a filament dryer is an essential tool if you want to get smooth, strong 3D printed parts consistently.
How a Filament Dryer Works
A filament dryer removes moisture from filament using gentle heat and circulating air. The filament is slowly heated to temperatures between 35°C and 65°C depending on the material. Warm, dry air is circulated around the filament to gradually remove absorbed moisture.
Most dryers have a bin or spool holder that holds your filament, along with a control box. The control box houses the heating element, fan, electronic control board, and displays your settings.
Quality dryers use PID temperature control for precise and even heating. A perforated or mesh bin allows airflow around each part of the filament. The low heat and steady airflow removes moisture from the filament without damaging it.
Drying for just a few hours before printing can restore old filament and improve the print quality of fresh filament as well.
Benefits of a Filament Dryer
Here are some of the benefits you’ll get from owning a filament dryer:
- Revive old filament – Restore filament that has absorbed moisture so it prints like new again. Save money instead of throwing away spools.
- Improve print strength – Drying filament results in better layer adhesion and stronger printed parts.
- Prevent warping – Wet filament warps more easily as it absorbs moisture and deforms during printing.
- Reduce stringing – Moisture creates surface bubbles that lead to oozing and strings between print moves.
- Get consistent prints – Dry filament means consistency between prints instead of intermittent quality issues.
- Higher print success – Cut down on failed prints from delamination, clogs, and other moisture-related issues.
- Better first layers – The first layer adheres perfectly to the print bed when filament is dry.
- Change materials easily – Dry different materials like PLA, PETG, TPU without swapping spool holders.
- Protect investment in filament – Stop plastic filament from degrading over time after being opened.
Clearly, a filament dryer is not just a luxury accessory. It’s a wise investment that pays for itself through better print quality, less wasted filament, and higher 3D printing success.
Types of Filament Dryers
There are a few different designs of filament dryers to choose from:
Passive dry boxes – An insulated box with dessicant that simply keeps filament dry. Good for storing unopened filament.
Heated dry boxes – Uses gentle heat and airflow to actively dry filament. The filament sits on an external spool.
Spool holder dryers – Contains an internal holder or spindle to mount the filament spool directly inside.
Filament cleaner systems – Combines drying with additional filament cleaning features.
The most popular options are heated dry boxes and spool holder dryers. Here’s an overview of the differences:
Heated Dry Box
- Holds loose filament or reels in a mesh basket
- Filament sits externally on a spool holder
- Entry and exit ports for filament to printer
- Typically small desktop size
Spool Holder Dryer
- Enclosed chamber with integrated spool mounts
- Entire filament spool fits inside
- Door for loading spools directly in the chamber
- Larger size than dry boxes
Heated dry boxes take up less space, while integrated spool dryers completely contain the filament. Dry boxes can only hold smaller spools while spool dryers have adjustable mounts for different sizes.
Key Filament Dryer Features
Here are the most important features to look for in a quality filament dryer:
- Temperature control – PID controllers maintain precise temperatures in a range from 30°C to 70°C.
- Filament capacity – The weight capacity or spool size the dryer can accommodate.
- Air circulation – A fan and vents or mesh walls promote even drying.
- Monitoring – Displays show time elapsed, temperature, and other drying stats.
- Footprint – The external size or footprint required for the dryer.
- Filament compatibility – Materials the dryer can safely dry like PLA, ABS, Nylon, PETG, etc.
- Additional features – Special modes for different materials or filament cleaning abilities.
- Portability – For taking your dryer to remote printing locations.
- Reliability – A track record of dependable performance from a reputable brand.
Look for a dryer that fits your budget while having the features and capacity you need. Even basic heated dry boxes work remarkably well for PLA and other materials.
How To Dry Filament
Drying filament is very easy with the right machine. Just follow these simple steps:
- Set your desired temperature based on the filament material. For example, 60°C for PLA or 70°C for PETG.
- Load the filament into the mesh bin or onto the spool holders. Make sure filament is not tightly coiled or bunched up.
- Turn on the machine and allow it to preheat fully, which takes 10-20 minutes.
- Let the filament dry for 2 to 6 hours. Longer drying times are better for very wet filament.
- The filament is ready to print when the drying cycle finishes!
Be sure to let the filament cool down before removing it from the dryer. Then you can go right into printing with perfectly dry filament.
How Long To Dry Filament
The time required to dry filament depends on:
- Filament material – ABS dries faster than Nylon, for example.
- Level of moisture – Drying takes longer if the filament is very wet.
- Temperature – Higher temps speed up drying.
- Amount of filament – Smaller batches dry faster.
Here are some general guidelines for drying times at 60°C to 70°C:
- PLA – 2 to 4 hours
- ABS – 3 to 6 hours
- Nylon – 4 to 8 hours
- PETG – 3 to 5 hours
Test prints let you check if the filament is fully dry yet. You’ll get the best results from drying overnight or for at least 5-6 hours.
Best Filament Dryers
Now let’s look at some of the top-rated filament dryers that will save you time, money, and failed prints.
Polymaker PolyBox
Polymaker is a leading filament brand that makes the exceptional PolyBox dryer optimized for their materials. It uses a high-precision PID heater and PID cooling system for accurate temperature control.
The PolyBox can hold up to 3 kg of material in the stainless steel mesh basket. It displays real-time temperature and time elapsed on the OLED screen. The compact size takes up minimal space next to your printer. It’s also portable and even battery powered for travel use.
This is one of the most popular filament dryers for its reliability, performance, and smart features focused on Polymaker’s own filaments.
PrintDry Filament Dryer Pro Series
The PrintDry Pro dryer has an integrated spool holder that fits spools up to 3 kg inside the drying chamber. It uses a perforated aluminum spool holder and stainless steel housing for even 360° drying.
You get precise PID temperature control from 30°C to 80°C for any material. The digital display shows temperature, time, and alerts. It has storage for spare spools and a see-through door to monitor drying progress.
This is an excellent choice for a larger enclosed dryer that handles full size spools with ease. Plus it comes from a company focused just on filament drying solutions.
FlashForge Filament Dryer
Here is a more affordable filament dryer option from popular 3D printer manufacturer FlashForge. It has a PTC heating element and three temperature presets: 50°C, 60°C, and 70°C.
The drying bin holds up to 700g of filament and uses a stainless steel mesh design for airflow. It has an integrated cable holder and inlet guide tube for feeding filament to your printer. The compact desktop size takes up minimal space.
For just $99, this dryer gives you reliable low temperature drying performance in a tiny package. It’s a great budget pick.
Flodry Filament Dryer
The Flodry filament dryer uses an innovative downdraft drying approach. Filament hangs vertically from the top while dry air is blown down over the filament. This vertical airflow design provides very fast and even drying.
It accommodates spools up to 5kg with adjustable holders. You get precise temperature control from 30°C to 70°C for any material. The easy slide-out shelf simplifies loading and unloading filament.
This downdraft design dries filament extremely efficiently in a compact footprint. It’s one of the fastest dryers available.
Keenovo Technology Dryer
Keenovo makes industrial-grade heating equipment including this high-end filament dryer. It uses an all-metal construction with stainless steel, anodized aluminum, and a steel spool holder.
The PID temperature controller ranges from room temperature up to 80°C. It displays real-time graphs of temperature and humidity. The spool rack fits spools up to 3 kg. You get incredibly even and precise drying performance.
While pricey, this filament dryer is built to last with extreme accuracy and reliability. It’s a workhorse for high volume printing.
DIY Filament Drying
You can also dry filament without buying a machine using DIY methods. Here are a few options:
- Food dehydrator – Remove trays and let filament hang inside, heated to 40°C to 50°C.
- Oven – Use lowest setting around 50°C with door propped open.
- Storage container – With dessicant beads and rolls of filament.
- Sunlight – Lay filament out in direct sunlight.
Keep in mind DIY drying lacks fine temperature control and carries risks. Ovens can overheat and damage filament, for example.
A proper filament dryer with regulated gentle heat is safest for your filament. It will also save you a ton of time and effort.
Maintaining Your Filament Dryer
Like any appliance, filament dryers need some periodic maintenance to keep working their best:
- Clean heating elements and fans of dust buildup.
- Check door seals for any air leaks.
- Make sure temperature sensors are accurately calibrated.
- Replace dessicant beads if your dryer uses them.
- Apply lubricant to spool holder bearings or other moving parts.
- Test power cords and electronics for damage.
- Clean exterior and interior with isopropyl alcohol.
Refer to your instruction manual for the maintenance recommendations specific to your dryer model. With proper care your dryer should deliver years of service.
Get Better 3D Prints With a Filament Dryer
A dedicated filament dryer is by far the most convenient and effective way to prevent moisture-related print quality issues. They save you time, wasted filament, and failed prints using engineered drying technology.
Carefully choose a high quality dryer designed for your specific needs. Popular options like Polymaker’s PolyBox and PrintDry Filament Dryers provide commercial grade drying performance at reasonable prices. Even basic models still dramatically improve drying compared to DIY methods.
Now that you know how filament dryers work and the best options available, you can improve your print quality overnight. Say goodbye to hydroscopic filament and start printing perfect models every time with an efficient filament dryer.
