Drying process overview
Frequently asked questions
Which 3D printing filaments should be dried?
ABS, PMMA, PA (Nylon), PC, PET, PETG, POM, TPU, advanced filaments like CF filled PA or flexible filaments should be dried before printing. We also recommend to feed preconditioned PLA or PP filaments, because it can improve the reliability of the printing process.
What does determine the ability of a 3D printing filament to absorb moisture?
It depends on the polarity of the main polymeric component, i.e. its chemical nature.
Why do the undried filaments print so bad?
The main negative effect of excessive moisture during processing of polymers is hydrolysis, i.e. the chemical breakdown of polymer macromolecules due to reaction with water at high temperatures.
What impact does moisture have on 3D printing process?
In the context of 3D printing high moisture content in the filament can give rise to the following 3D printing defects:
- foaming, bubble formation, opaque appearance. At the polymer processing temperatures the water will evaporate, expand, and form bubbles in the polymer melt, which will result in bad surface properties and deteriorate the optical properties of the final parts;
- more oozing and more strings. Water reduces the viscosity of the polymer melts, so they become more liquid;
- pronounced warping. The prints from undried material usually show worse dimensional stability, and become more prone to warping;
- bad interlayer adhesion, compromised mechanical properties. Due to the hydrolysis, the long macromolecule chains are split into shorter ones. This leads to the compromised mechanical properties of the solid parts, which can lead to the delamination during printing or even failure of 3D printed parts in service;
- colour changes. Hydrolysis products often lead to the colour changes of the polymer.
What impact does drying have on the quality of 3D printed parts?
The main advantage of using dryers is that it will reduce the number of moisture-induced 3D printing defects. We have also observed that the parts printed with dried materials sometimes exhibit more accurate dimensions than the parts printed with undried material (see Figure below). So if the dimensional stability of your 3D printed parts is important, we strongly advise you to use a filament dryer. In general, the use of dryers increases the overall 3D printing success rate, and makes the 3D printing process more stable, thus, even enabling a continuous 3D printing.