Influence of drying temperature and graphite concentration on the performance of graphite-based conductive ink

Abstract

This paper examines how drying temperature influences the electrical and mechanical properties of graphite-based conductive ink. Special emphasis was placed on electrical conductivity and abrasion resistance. The ink formulations were prepared using graphite powder with a particle size below 20 μm as the conductive component, while a commercially available water-based printing ink served as the binder. To evaluate the influence of filler loading on the formation of conductive networks, graphite was incorporated at concentrations of 30 wt.% and 40 wt.%. To ensure a uniform coating layer, the inks were applied onto a smooth polymer-coated paper substrate using a glass rod. The printed samples were dried for 15 minutes at four different temperatures (60 °C, 80 °C, 100 °C, and 120 °C). Electrical performance was assessed via surface resistance measurements, while abrasion resistance was used to assess the durability and adhesion of the conductive layers. Based on the measurements, it was found that both drying temperature and graphite concentration significantly influence the performance of the coatings. Improved electrical conductivity was observed at higher graphite content, while drying at moderate temperatures promoted better particle contact and a more stable conductive network. However, excessively high drying temperatures led to reduced mechanical stability, likely due to binder degradation. In our experiment, particular attention was given to maintaining constant homogenization, application with a glass rod and drying time. This paper contributes to a better understanding of the role of processing parameters in graphite-based conductive inks and supports the optimisation of formulations and drying conditions for functional printed materials.