Does PETG Filament Need to Be Dried

PETG (polyethylene terephthalate glycol-modified) has become a widely used filament in 3D printing due to its strength, durability, and ease of printing compared to other materials. A common question among 3D printing enthusiasts is whether PETG needs to be dried prior to use.

The short answer is that dried PETG can produce better print quality, but drying is not an absolute requirement. PETG is hygroscopic, meaning it absorbs moisture from the air over time. This can lead to stringing, reduced layer adhesion, and weaker prints if excessive moisture is present. However, PETG is not as severely affected by moisture as materials like Nylon, so drying is more of an optional step.

Many manufacturers recommend drying PETG at around 50–60°C for 4-8 hours prior to printing. This helps remove any ambient moisture absorbed by the filament during storage and shipment. Drying results in reduced cracking and popping sounds during printing, along with a smoother extrusion process. The optimal moisture content for PETG is around 0.02%.

However, for most casual printing applications, acceptable results can still be achieved without pre-drying PETG. Storage in an air-tight container with desiccant packets helps maintain lower moisture levels. Drying may be most beneficial for large, high-resolution PETG prints where quality is paramount. The effects of moisture are less noticeable on smaller, simpler prints.

Factors that can influence the need for PETG drying include ambient temperature and humidity in the storage environment, the age of the filament, and the precision required for the print. New PETG straight from a vacuum-sealed package likely requires little to no drying at all. But filament left out for months in a humid environment may develop moisture levels that impair print quality.

In summary, drying PETG prior to printing is recommended but not strictly necessary in most cases. While drying can optimize PETG’s print performance, acceptable outcomes can still be achieved with non-dried filament. PETG’s moisture tolerance makes drying more optional compared to other 3D printing materials.

FAQs

Here are some examples of frequently asked questions and answers about drying PETG filament for 3D printing:

Q: Does PETG filament need to be dried at all before printing?

A: Drying PETG is recommended for optimal print quality, but is not absolutely required. Many find acceptable results printing PETG straight from the bag without drying.

Q: What problems can occur if PETG is not dried properly?

A: Insufficient drying can lead to issues like stringing, poor layer adhesion, weaker prints, and discoloration. However, effects are usually minor if ambient conditions are not extremely humid.

Q: How should I properly dry PETG filament?

A: Dry PETG at 50–60°C for 4-8 hours before printing. Use a filament dryer or oven if available. Lower temperatures and longer times can also work.

Q: How can I tell if my PETG filament needs drying?

A: Signs like cracking sounds during extrusion, stringing, rough layers, or filament snapping indicate excessive moisture in PETG. Try drying the filament to see if it improves.

Q: Do I need to keep drying PETG over and over before printing?

A: Generally just drying spools once prior to initial use is sufficient. Only re-dry if the filament is subjected to very humid conditions for extended periods.

Q: Is dried PETG filament safe to print after being exposed to air again?

A: It’s best to print dried PETG soon after removing it from the dryer to limit the re-absorption of moisture. But PETG can tolerate some air exposure without major quality issues.

Q: Can I dry used PETG filament to revive print quality?

A: Yes. Re-drying used PETG that has absorbed moisture from extensive printing or storage can help restore print quality.

Q: Is drying absolutely necessary for printing high-quality PETG parts?

A: Proper drying is recommended for maximum precision, especially for large, intricate PETG prints. But for simpler prints, drying is not always mandatory.