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How Long Does It Take To Dry PETG Filament?

3D printing filaments such as PETG often absorb moisture, dampening the effectiveness of the material for a hitch-free printing session. Most 3D printing professionals and hobbyists often have to dry the filaments before use if they get wet. If you’re one of them, you may wonder how long it will take to dry PETG filament.

It takes one to six hours to dry PETG filament. The exact duration depends on the wetness of the filament and your selected drying method. Mildly wet filament dried in an oven can dry out in less time, while very wet filament in a food dehydrator can take five to six hours to dry out.

The rest of this article will cover all you need to know about drying PETG filaments when they get wet. I’ll also cover all you need to know about making sure the filaments don’t get wet in the future.

Why It Takes Long To Dry PETG Filament

Though six hours may seem like a long time, it takes this long to dry PETG filament because it is a hygroscopic material. Hygroscopic materials have spongy layers that soak up and retain moisture. 

The layers become very wet if the material is exposed to moisture-rich air long enough. Because moisture doesn’t escape from hygroscopic materials as quickly as it does from flat non-hygroscopic materials or surfaces, drying PETG filament takes several hours.

What Are the Differences Between Dry and Wet PETG Filament?

The main differences between dry and wet PETG filaments are the quality of the finished product. Dry PETG will produce glossy and consistent final prints, while wet PETG products appear more brittle.

Wet PETG filaments also produce textured 3D prints instead of satin finishes because of the air bubbles found in the filament. 

Furthermore, increased filament humidity causes stringing around the edges and corners of the print. This results in the surface quality of your prints becoming severely inhibited and causes the smooth parts in your design to look rough in the final output.

Characteristics of Wet PETG Filament

It is not always easy to use the eyeball test to know whether your PETG filament is wet or not. Here are some top characteristics of wet PETG filaments you should watch out for:

  • Excessive stringing while printing.
  • Production of uneven extrusion lines.
  • Reduced tensile strength in final 3D prints.
  • Filament oozing during the extrusion process.
  • Cracking or popping sounds during the printing process.

When you notice any of these signs, it’s a good indication that you’re working with wet PETG filament. Fortunately, drying the rest of the filament will allow you to complete a high-quality print without any damage.

How To Dry PETG Filament

There are several options available for you to consider when it comes to choosing ways to dry PETG filament. Here are some options you can consider:

Oven Drying

One of the easiest ways to dry out PETG Filament is by using a regular home oven

For the best results, you should set your oven’s drying temperature at 65-70°C (149-158°F) and run it for around 4-6 hours to completely dry out the filament. 

Make sure to clean out the oven before drying your filament. Grease and food caked-on food particles around the oven may interact with the filament, which makes a clean oven essential for this option.

Using a Designated Filament Dryer

Some manufacturers have produced filament dryer boxes that allow users to dry filament spools. Products like the SUNLU 3D Printer Filament Dryer (available on Amazon.com) can dry your filament at temperatures between 95 and 130°F (35-55°C)This dryer can work for hours at a time, up to 24 hours at a stretch if necessary.

These systems typically come with a digital display that allows easy temperature control. Additionally, some of them also allow drying more than a single filament spool simultaneously. If you set the temperature to the lowest range, you can store filament spools you need for a project overnight without worrying about them getting wet before you’re ready to start or resume a project.

Food Dehydrator

Many 3D printing enthusiasts buy food dehydrators as a designated dryer for their PETG filaments. With the temperature set at 70°C (158°F), you can expect wet filament to dry out in less than 6 hours.  

There are many food dehydrator options in the market if you want one. The COSORI Premium Dehydrator from Amazon.com is a good option to go with. It can dry your filament at 95-165°F (35-73°C), and the design allows you to dry up to 5kg (11 lbs) of filament roll simultaneously.

How To Keep Your PETG Filament Dry

While there are many approaches to drying wet PETG filament, you can save yourself the drying time by storing the filament properly to prevent moisture absorption. Here are some top tips you can work with to ensure your filament is ready to go at all times:

  • Store your filament in a low humidity room. The ideal room should be airy but without the risk of moisture accumulation (through windows or doors). You may also install dehumidifiers in the room to keep the moisture content in the air down to the barest minimum.
  • Store the filament in airtight bags. Ziploc bags laced with desiccants can help keep your filament dry. Buy a few units and ensure all your filament spools are carefully stored away in them.
  • Store filament in dry boxes. These boxes are as effective as Ziploc bags and are much easier to work with. 

Ideally, you should place your filaments in airtight boxes or bags and then store them away in a low humidity environment (one that preferably includes a dehumidifier). Your chosen room should also have a humidistat so you can keep an eye on moisture levels in the room.

Final Thoughts

Working with wet PETG is a sure way to end up with a low-quality 3D print. Fortunately, it doesn’t take too long to dry PETG filament. In most cases, putting the filament spool in the oven, food dehydrator, or a specialized filament dryer for 4-6 hours is enough to remove all humidity and return the filament to the perfect shape for your 3D printing projects.

When you’ve dried the filament spool, it’s important to ensure it stays dry if you’re working on an ongoing project. You can achieve this by storing dry filament in a low humidity environment at all times.