Proper storage and care of filaments is crucial to avoid moisture damage and ensure consistently high print quality. Filaments can be affected by moisture from the air, leading to issues such as blistering, irregular extrusion, and brittle print results. To prevent these problems, it is important to follow appropriate storage methods and care tips.

Why moisture is a problem for filaments

Many common 3D printing filaments, especially PLA, ABS, PETG, TPU, and Nylon, are hygroscopic, meaning they absorb moisture from the air. When the filament absorbs moisture, it can cause the following problems during printing:

  • Blistering: When heating moist filament, steam bubbles form that affect print quality.
  • Brittle Filaments: Moisture can make the filament brittle, leading to breaks during printing or feeding.
  • Poor adhesion and surface quality: Trapped moisture can prevent the first layer from adhering well and cause unsightly surfaces.

To avoid these problems, it is important to store and maintain filaments properly.

Recommended storage methods for different filaments

1. Using dry boxes

A dry box is one of the most effective methods to keep filaments dry. These boxes are airtight and usually contain silica gel desiccant to absorb moisture from the air. Many dry boxes are even heated to dry the filament directly from the box during printing.

  • Advantages: Protects filaments long-term from moisture, offers a heated option for particularly hygroscopic filaments.
  • Recommended filaments: All filament types, especially nylon, TPU, PETG, and PVA.

2. Vacuum bags with desiccant

A cost-effective method for storing filaments is using resealable vacuum bags along with desiccant bags (e.g., silica gel). These bags remove oxygen from the air and thus reduce the moisture that contacts the filament.

  • Vacuum bags: Place the filament spools together with a desiccant bag inside the vacuum bag and remove the air.

  • Desiccant: Silica gel absorbs residual moisture in the bag and keeps the filament dry.

  • Advantages: Affordable, easy to use, ideal for filaments not used daily.

  • Recommended filaments: PLA, ABS, PETG, Nylon, TPU.

3. Airtight containers with desiccant

An airtight container equipped with desiccant can also serve as filament storage. This method is ideal for those seeking a simple and flexible solution.

  • Containers: Use airtight containers large enough to store multiple spools. These containers keep humidity low as long as you regularly replace the desiccant.

  • Desiccant: Silica gel or calcium chloride desiccant in bags or open containers that absorb humidity.

  • Advantages: Reusable, inexpensive, ideal for storing multiple spools.

  • Recommended filaments: PLA, ABS, PETG, TPU, Nylon.

4. Dry rooms or cabinets

In professional environments where many different filament types are used, a dry room or a dry cabinet can be a solution. These rooms or cabinets are kept at low humidity by special dehumidifiers.

  • Advantages: Ideal for large-volume filament storage and professional use.
  • Recommended filaments: All filament types, especially for very hygroscopic materials like Nylon or PVA.

5. Drying boxes with heating

For very hygroscopic materials or filaments that have already absorbed moisture, a heated drying box can help. These boxes actively dry the filament while it is used in the printer.

  • Advantages: Perfect for materials like Nylon or TPU, which often attract moisture.
  • Recommended filaments: Nylon, PETG, PVA, TPU.

Tips for caring for and handling filaments

1. Keep filament dry

  • Replace desiccant regularly: If you use desiccant, make sure to replace or regenerate it regularly. Silica gel can be reactivated by heating it in the oven.
  • Avoid direct sunlight: Never store filaments in sunlight, as UV radiation and heat can damage the filament.
  • Use moisture indicators: Some drying boxes or containers are equipped with moisture indicators that show the moisture level inside the container. This helps you decide when the desiccant needs to be replaced.

2. Regularly dry filaments

Even if you store your filaments properly, they can still absorb moisture. Therefore, you should regularly dry your filaments, especially before large or sensitive print projects.

  • Oven method: Place the filament spool in the oven at a low temperature for a few hours (about 40-50°C for PLA, 60-80°C for Nylon). Make sure the temperature is not too high to avoid melting the filament.
  • Dry box: A heated dry box can actively dry the filament during printing.

3. Store different filament types separately

Different filament types react differently to moisture, and some require special care.

  • PLA: Hygroscopic but relatively easy to store. An airtight container with desiccant is usually sufficient.
  • ABS: Less prone to moisture absorption than PLA, but should still be stored dry and protected from light.
  • PETG: Highly hygroscopic, should always be stored in a dry box or airtight bags.
  • TPU: Particularly sensitive to moisture, always store in a dry box or vacuum packaging.
  • Nylon: Extremely hygroscopic, requires special storage conditions such as a heated dry box or vacuum bags.

4. Recycle used filaments

If you have filaments that have become unusable due to moisture or poor storage, recycle them properly. Some recycling services accept used or damaged filaments and convert them into new materials.

Conclusion

Proper storage and care of filaments is crucial to avoid moisture damage and ensure consistently high print quality. Use dry boxes, vacuum bags, or airtight containers combined with desiccants to protect your filaments from moisture. Especially for hygroscopic filaments like Nylon, PETG, or TPU, you should use heated dry boxes. These measures ensure that your filaments always remain in the best condition and you achieve optimal print results.