Use of Thermally Sprayed Heating Elements on Free-Form Geometries for Use in Plastic Injection Moulds

Thermally sprayed heating coatings have demonstrated initial success in reducing warpage in components manufactured via plastic injection moulding. These coatings allow highly dynamic and near-surface temperature control within the mould, positively impacting the manufacturability of plastic injection-moulded parts. However, previous studies have only focused on flat geometries. This study aims to develop strategies for coating free-form surfaces and assess their effectiveness as heating elements. Atmospheric plasma spraying was used to apply heating coatings to samples with various radii. Different coating strategies were evaluated, and their effects on the coating quality were analysed. The performance of these coated samples was then compared to that of previously known flat heating coatings through a series of heating tests. The results indicate that it is feasible to apply heating coatings to samples with radii, and successful heating tests were conducted using these samples. The quality of the coating system was similarly affected. The ability to apply heating coatings to more complex component geometries marks a significant step towards integrating this technology into industrial plastic injection moulding processes.