PEEK leaves the factory with a moisture content of less than 0.25 wt.%. We nevertheless recommend additional drying in order to obtain qualitatively high-grade extrudates. A drying cabinet is good for base powders. We recommend special drying periods for film applications. The maximum residual moisture is recommended to be < 0.02 weight-% for base powders and granules.
The most standard screw machines are suitable for PEEK processing provided that they can operate reliably at the required processing temperatures.
For screws and barrels, we recommend sufficiently corrosion- and abrasion resistant steels and bimetals. If conventionally nitrided parts are used, make sure that the VESTAKEEP
PEEK melt does not cool on the surface and solidify on the nitride layer. The adhesion can be so strong that cracks will form and the nitride layer can peel off from the steel core.
In the brochure VESTAKEEP
PEEK – Polyether Ether Ketone Compounds you will find comprehensive recommendations for processing by extrusion.