When moisture being absorbed into hygroscopic filaments, the water molecules are attached to the polymer molecule chains of filaments, forming a strong inter-molecular bond. This bond is what makes drying the filament difficult. The desiccant packs coming inside a filament package are not strong enough to break the inter-molecular bond and “pull” the moisture out of the filament. Instead, the desiccant packs help more to prevent water content in a filament from going up other than reducing it. On the other hand, if exposed the desiccant itself will become saturated with moisture and lose its much-needed moisture absorbing capacity. Desiccant packs cannot reduce the water content inside filaments.
What’s required for drying 3D printing filaments is a dryer that heats up a filament completely, breaks the moisture/polymer bonds, and moves the moisture to the filament surface where it can be carried away, leaving the filament dry and ready for high-quality 3D printing.