APP – Drying (PET)

PET is hygroscopic : it absorbs moisture from the air. It must therefore be dried prior to extrusion.

1. How to dry the material ?

It is good to dry 2kg of material at once ; you will have enough dry material to experiment with the settings, during the extrusion step. Drying takes time and, if you do not dry enough material to finish your experiment or your spool, you will not have the option to instantly dry more, once extrusion has started.

  • Place 2kg of your PET regrind in the hopper of the Airid
  • Screw the hopper firmly onto the Airid
  • Set the drying temperature on 140°C
  • Set the drying duration on 5h

2. If you have a moisture analyzer

You can set 140°C and 20min in your moisture analyzer.

The target moisture is 0.05%wt.

If, after the drying process, the residual moisture content is higher than this threshold, then maybe the drying settings need to be adjusted.