In the context of 3D printing using filament materials, it is essential to consider the sensitivity of the polymer material to moisture. Some filaments can be hygroscopic, absorbing moisture from the environment, and this can greatly affect the printing process and the characteristics of the material itself. Here are some important things to consider:


  • RELEASE OF WATER VAPOR, FUMES, AND SOUNDS: During extrusion at elevated temperatures, water trapped in the material's granules can vaporize rapidly, resulting in the release of water vapor, fumes, and sounds. In some cases, smoke may be visible, affecting the quality of the print.
  • MICROBUBBLES OR IMPERFECTIONS IN THE PRINT: Trapped moisture can cause microbubbles to form in the molten material during extrusion, resulting in imperfections on the surface of the printed object.
  • EXCESS FILAMENT BETWEEN PARTS (STRINGING): Moisture can affect the viscosity of the molten material, causing filaments to form between different parts of the printed object. This phenomenon, known as "stringing," may require post-press finishing operations.

FILAMENT DRYING: To address these issues, it is crucial to dry hygroscopic filaments thoroughly before printing. This process removes moisture trapped in the material's granules, ensuring that the filament is optimal for the printing process. Using vacuum dryers or ovens at specific temperatures may be necessary to get rid of excess moisture.

MATERIAL SELECTION: It is important to note that some filaments, such as PVA and PET-G, are known to be hygroscopic and require special precautions during use. Conversely, materials such as polypropylene (PP) may not require prior drying.

In summary, managing moisture is crucial when using filaments for 3D printing, and drying the material thoroughly will help ensure quality prints.