When cooling down from the melt phase to room temperature, PEEK shrinks about 3.5%. This means a printed track which 100 mm long typically wants to shrink to 96.5 mm, where applications typically require a geometric error a few tenths of millimeters.
To some extent, a linear expansion of the 3D model in X, Y and Z direction helps to compensate the errors a little bit, but this method typically requires multiple iterations, and it does not resolve local warpage of products. Therefore, it is not sufficient to meet the accuracy requirements for most applications.
The standard routes to overcome this is to print slowly crystallizing materials such as PEKK, to add carbon fibres to reduce shrink, or to cool down the material quickly in the printer and recover crystallinity by an additional thermal treatment. None of these avenues offer the ability to print accurate products with the native properties of pure PEEK.
Bond3D, together with partner AniForm, have developed unique software to calculate local shrink and warpage during printing, and locally compensate the toolpaths of printed tracks in X, Y and Z direction in a way that the final product meets or even exceeds accuracy requirements.
The solution is revolutionary in that in fact a product with a warped shape is printed, which after cooling down to room temperature results in a part which accurately conforms to the intended shape.
Printed tracks are modified in all directions, implying that printed slices are no longer flat.