How to Dry PLA Filament: A Complete Guide

PLA (Polylactic Acid) filament is one of the most popular materials used in 3D printing due to its ease of use, affordability, and biodegradable nature. However, like many other 3D printing filaments, PLA is hygroscopic, meaning it absorbs moisture from the air. Wet PLA filament can cause poor print quality, nozzle clogs, and inconsistent extrusion. Drying PLA properly can restore its original printing performance. This guide will explain why PLA filament absorbs moisture, how to identify wet filament, and various methods to dry it effectively.

Why Does PLA Filament Absorb Moisture?

PLA filament is made from cornstarch or sugarcane, making it naturally biodegradable and slightly porous. Because of its chemical structure, PLA easily attracts water molecules from the air. Over time, exposure to humidity can lead to water absorption, which affects its printing quality.

Signs That Your PLA Filament Needs Drying

Before drying your filament, you need to confirm whether it has absorbed moisture. Here are some common signs of wet PLA filament:

1. Popping and Bubbling Sounds

• If you hear crackling or popping sounds during printing, it means the filament has moisture trapped inside. When heated, the water inside the filament turns into steam, causing these noises.

2. Stringing and Oozing

• Wet PLA tends to create excessive stringing and oozing between prints because the moisture in the filament disrupts smooth extrusion.

3. Inconsistent Extrusion

• If your 3D prints appear uneven, have gaps, or show under-extrusion, it could be due to moisture interfering with the melting process.

4. Rough or Brittle Prints

• Moist PLA often results in weak prints that break easily or have rough textures instead of smooth surfaces.

How to Dry PLA Filament

Now that you know how to identify wet PLA filament, let’s explore different ways to dry it effectively.

1. Using a Filament Dryer

A filament dryer is one of the best ways to remove moisture from PLA filament. These devices are specifically designed to heat the filament at a controlled temperature and maintain a dry environment.

Steps:

1. Load the wet filament into the dryer.
2. Set the temperature to 40-45°C (104-113°F) for PLA.
3. Let it dry for 4-6 hours.
4. Use immediately or store in a dry box.

2. Using an Oven

A standard kitchen oven can also be used to dry PLA filament, but it requires careful temperature control to avoid melting the plastic.

Steps:

1. Preheat the oven to 40-45°C (104-113°F).
2. Place the filament spool on an oven-safe surface.
3. Let it dry for 3-6 hours.
4. Remove and store properly.

Tips:

• Use an oven thermometer to ensure accurate temperature.
• Never exceed 50°C (122°F), as PLA can soften and deform.

3. Using a Food Dehydrator

A food dehydrator works similarly to a filament dryer and can be a great alternative for drying PLA.

Steps:

1. Set the temperature to 40-45°C (104-113°F).
2. Place the filament inside the dehydrator.
3. Let it dry for 4-6 hours.
4. Store in an airtight container after drying.

4. Using Silica Gel in a Storage Box

If you don’t have an oven or dehydrator, silica gel packets can help absorb moisture over time.

Steps:

1. Place the filament spool in an airtight container.
2. Add silica gel packs inside the container.
3. Leave it for 24-48 hours.
4. Check and replace silica gel packs as needed.

5. Using a Heat Lamp

A heat lamp can help dry PLA filament gradually, but it requires patience.

Steps:

1. Hang the filament spool near the heat lamp.
2. Keep it under gentle heat for 6-12 hours.
3. Store properly after drying.

Best Practices for Storing PLA Filament

Once you’ve dried your PLA filament, it’s essential to store it properly to prevent it from absorbing moisture again.

1. Use Airtight Storage Containers

• Store filament in a sealed plastic container or vacuum-sealed bag with silica gel packs.

2. Use a Dry Box

• A filament dry box with a built-in heating element keeps the filament dry while in use.

3. Keep in a Low-Humidity Environment

• Store filament in a cool, dry place away from direct sunlight and high humidity.

FAQs

1. How long does it take to dry PLA filament?

• Drying time varies based on the method used. Generally, 4-6 hours in a filament dryer or oven is sufficient.

2. Can I use a microwave to dry PLA filament?

• No, microwaving filament can cause it to melt unevenly and may damage both the filament and microwave.

3. Can I dry PLA filament multiple times?

• Yes, PLA can be dried multiple times, but excessive heating may degrade its quality over time.

4. What happens if I don’t dry my PLA filament?

• Wet PLA leads to poor print quality, including stringing, under-extrusion, and weak prints.

5. How can I prevent PLA filament from absorbing moisture?

• Always store it in an airtight container with silica gel when not in use.

Conclusion

Drying PLA filament is essential for maintaining high-quality 3D prints. Moisture can significantly impact print quality, causing issues like bubbling, stringing, and weak prints. Fortunately, methods such as using a filament dryer, oven, food dehydrator, or silica gel can effectively remove moisture. Proper storage, such as airtight containers and dry boxes, can help keep PLA filament in good condition for longer. By following these guidelines, you can ensure consistent and high-quality prints with PLA filament.