Experimental Study on the Effective Thermal Conductivity of 3D‐Printed PLA Annular Thermal Insulators With Different Infill Parameters

ABSTRACT 3D‐printed parts have the potential to be used as low‐temperature thermal insulators in different applications where custom geometries and aesthetics are required. The present paper describes the experimental process for measuring the effective thermal conductivity of different 2D infill patterns and infill densities in 3D‐printed annular thermal insulators made from PLA, placed around a heated cylindrical electrical resistance. The temperature differences between inner and outer radii are measured with thermocouples in five points across the semi‐circumference in order to capture the anisotropic behavior of convection within infill voids, which depends on the direction of gravity. Heat flux across the insulator is determined by measuring the electrical power input, and the apparent thermal conductivity is calculated based on the temperature differences. Common infill patterns are tested, with infill densities of 30%, 35%, and 43%.