Characterization of Polypropylene/Titatium Dioxide Composites used for 3D Printing of Dielectric Functionally Graded Insulators

Dielectric functionally graded insulation (d-FGI) can significantly increase surface flashover voltage without increasing the geometric complexity of insulator. 3D printing technology has been proved to be an effective method for manufacturing d-FGI. The most widely used Fused Deposition Modeling (FDM) technology in 3D printing can use recyclable thermoplastic materials as printing raw materials, which solves the problem that traditional thermoset insulating materials cannot be recycled. In this study, polypropylene (PP), a thermoplastic material with excellent electrical insulation properties, was used as matrix, and high-dielectric titanium dioxide (TiO2) was used as inorganic filler to study dielectric properties and 3D printing feasibility of the composites. The effect of filler content on dielectric properties of the composites (i.e., relative permittivity, dielectric loss, and volume resistivity) is studied. At the same time, the influence of filler content on 3D printing properties of the composites (i.e., melt flow rate) has also been studied, which is critical to the 3D printing accuracy of d-FGI. This research lays an important foundation for the accurate manufacturing of 3D printing for d-FGI.