Thanks to Eibos for sending over their Polyphemus Filament Dryer to test out!

Introduction

3D printing filament absorbs moisture from the air over time. This means that your print quality can vary depending on how long ago the filament was opened. Potential problems caused by wet filament can include poor layer adhesion, stringing, and lackluster surface finish.

I wanted to know how much of a difference drying the filament would make, so I tested the Eibos Polyphemus Filament Dryer using my material strength test rig.

Assembly

The Polyphemus Filament Dryer comes in a few pieces that need to be assembled.

The main body is made of a clear plastic that allows you to see the filament inside.

There is a vent on the top of the dryer case to allow airflow from the drying unit, which is located in the base. This vent is meant to be closed when the dryer is not running, to allow filament to be stored in the dryer. The vent is opened when the dryer is running to allow the moisture to escape.

The base is the only active component of the dryer. It has a fan and a heater to dry the air inside the dryer as well as the temperature sensor, display and controls. This means that if you want to dry a larger spool, you can easily swap out the top part of the dryer for a larger one, or use the: Eibos 3KG Extension.

Even 5KG spools fit on the Polyphemus base, but you'll need a larger top to cover the spool.

Experiments

To test out the Polyphemus Filament Dryer, I printed test coupons out of three different types of filament which included 2 different types of ABS and one PLA.

All three filaments were opened from their new packaging at the same time, about a year ago, and stored together in the same bin with desiccants.

I then printed coupons out of each material, 4 before drying and 4 after drying for the recommended amount of time.

Looking at the tensile strength results, performance improved 0.8% on average for the dried filaments. While this difference is small, I store my filament responsibly. I suspect that if the filament had more opportunity to absorb water, or were a more hygroscopic material, the difference would be more pronounced.