How to Dry Wet 3D Printer Filament - Simple and Easy Ways

All FDM 3D printing filaments are plastic polymers and love to absorb moisture, which can damage them if not stored properly. The drier the filament, the better the print quality. Therefore, ensuring dry material before printing is crucial. This blog provides a complete guide on how to dry your wet 3D printer filament, offering recommend drying temps and times for different types of filament.

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The Importance of Dry 3D Printing Filament

Stringy 3D object printed with wet filament

(Left: 3D print without stringing; Right: 3D print with stringing)

3D printer filaments such as PLA, nylon, ABS, and others are all hygroscopic, meaning they have a strong tendency to absorb moisture. Nylon, ABS, and PVA are even more prone to moisture absorption than PLA and PETG. However, it's crucial to keep all of them dry before printing because moisture can damage their mechanical performance.

Once a filament absorb moisture that is used for 3D printing, it tends to expand and become brittle, affecting print accuracy and quality. It's ideal to keep your filament as dry as possible to achieve high-quality 3D prints. If, unfortunately, your printing material has become damp due to improper storage, it's not irreparable; there are some simple and safe methods below available to dry them out.

How to Check If Your Filament is Wet

Check the diameter of 3D printer filament

Due to the hygroscopic nature of materials, certain signs indicate wet filament, requiring immediate drying before starting your printing. Checking the filament for changes in color and brittleness is a quick and easy method. Additionally, observing print quality for imperfections or reduced bed adhesion could indicate potential issues with the material. Inspecting printer components like the nozzle and extruder can also help determine if your filament requires drying.

Specific indicators that tell your 3D printer filament may need drying:

  • Poor print quality: This occurs when your printer is under-extruding wet filament, resulting in printing defects such as heavy stringing, bad overhangs, and sagged bridges.
  • Poor performance: When the material contains moisture, it becomes brittle and soft, losing its original rigidity. Additionally, the colors of wet filament easily fade, lacking their initial shine and vibrancy.
  • Clogged nozzle: Contaminated material with impurities and moisture inside can block the nozzle, leading to bubbling, popping sounds, and the release of water vapor during extrusion.

Some tools can also assist in checking if your filament is wet. Use a moisture meter to detect the humidity of the filament and hidden moisture. Additionally, use calipers to measure the diameter of your filament; a significant deviation from the initial diameter means it has absorbed moisture and expanded.

Best Ways to Dry Your 3D Printer Filament

1. Oven

A kitchen oven can dry wet filament, which is an easily accessible household appliance. However, precise temperature control is necessary, typically requiring the oven to be set at its lowest temperature. It's common for the internal temp to be slightly higher than the set temp after preheating, so use a thermometer to ensure it matches your target temp.

Next, place the filament on a pan into the oven, avoiding proximity to heating elements as this can ruin the entire spool of filament. Finally, use an external thermometer to constantly monitor if the oven is maintaining a steady temp to prevent overheating and melting your filament.

Pros Cons
  • Easily accessible in the kitchen.
  • No additional expenses on dryer equipment.
  • Requires temperature monitoring.
  • Uneven temperature distribution.
  • 2. Food Dehydrator

    If you want to improve the safety and stability while drying filament, consider a food dehydrator. It is designed for drying fruits, vegetables, and meats by slowly removing excess moisture at low temperatures, usually lower than an oven. What's more, the round shape of the dehydrator fits very well to a spool of filament, but its capacity is small. It probably drys only one or two spools at a time. To reduce the budget for drying filament, buying second-hand food dehydrators is inexpensive.

    Pros Cons
  • Safer and more stable compared to an oven.
  • Affordable and easy to access.
  • Limited capacity.
  • Longer drying time.
  • 3. Filament Dryer

    A filament dry box is specifically designed for 3D printing filament rather than cakes or food. It is professional yet easy to operate, equipped with a built-in timer and a digital display, and this greatly enhances drying efficiency. Some filament drying boxes can even feed your printer while drying, saving drying time. The main disadvantage is the cost; a single-spool dryer box typically ranges from $40 to $50, while those holding two spools can cost as much as $100 to $200.

    Pros Cons
  • Professional and easy to use.
  • Safely and effectively dries filament.
  • Expensive cost.
  • Limited capacity.
  • How Long to Dry 3D Printing Filament

    It generally takes about 4-6 hours to dry your wet filament. High moisture material such as Nylon and ABS, might require even longer drying times. For heat-resistant filaments like ABS, Nylon, and ASA, the drying temp can be slightly higher than for other materials. Here are suggested drying times and temp ranges for common 3D printing materials. Adjust drying times based on the material's moisture rate, the type of dryer used, and the drying temp.

    Material Drying Temps Drying Time
    PLA 40-45°C 4-6 hours
    PETG 60-65°C 4-6 hours
    ABS 70-80°C 4-6 hours
    Nylon 75-85°C 4-6 hours
    ASA 80-85°C 4-6 hours

    Prevention for Wet Filament

    Vacuum package to keep filament dry

    (Anycubic 1.75mm 3D printer filament)

    Properly storing your filament ensures it remains dry at all times, effectively preventing moisture and dust damage. No need to dry your filament every time you begin printing when using well-protected materials. If your workshop environment is somewhat humid, or if you can't use up an opened spool of filament within a month, it's advisable to store it in plastic storage bags or boxes with good sealing properties. What's more, combining the storage method with desiccants and hygrometers can further enhance the drying effect. Regularly check the humidity of stored filament, and inspect for signs of increased brittleness or changes in diameter by measuring it with calipers to detect any swelling due to moisture absorption.

    Anycubic, a reliable brand, offers affordable 3D printers and high-quality filaments for 3D printing. They provide 1.75mm filament suitable for 3D printers with a 4mm nozzle, which is a standard size for most printers. It ensures a diameter tolerance of ±0.02mm for their 1.75mm filament, effectively preventing nozzle clogs and maintaining printing accuracy. The store offers a variety of filaments, including Basic PLA, PLA+, PETG, ASA filament, and more.

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