Evaluation of thermal properties of PEEK samples made by MEX

The work studies the Polyether ether ketone (PEEK) specimens realized with the material extrusion (MEX) process, evaluating thermal material properties for potential application for polymer heat exchangers. The research investigates the influence of infill density on the thermal properties of PEEK components. A specific instrument measured PEEK specimens' thermal conductivity, thermal diffusivity, and specific heat. The procedure initially required a two-point calibration with references in the investigated ranges, followed by measurement with variable-filled specimens from sparse (20% infill) to full (100% infill). The results indicate that a decrease in the infill value causes a positive reduction in the thermal conductivity and specific heat. In contrast, the diffusivity remains stable with the infill variation.