Geocells are polymeric confinement systems widely used in foundations, pavements, retaining walls, embankments and slopes. Most of the existing studies on the performance of geocell reinforced soils use either commercial geocells or handmade geocells fabricated from geogrids, geonets or geotextiles. However, these studies often struggle to accurately quantify the reinforcing mechanisms of geocells due to disparities in geometric scaling and prefixed material properties. In this regard, 3D printing technology holds significant value, as it enables the fabrication of geocells in all possible dimensions, textures and mechanical properties. In the current study, honeycomb shaped geocells were fabricated using ultrasonic welding of 3D printed polypropylene sheets. This research investigates the interface shear strength of various interfaces within the 3D printed geocells, such as the sand-geocell (top and bottom) interface and the sand-polypropylene sheet (side) interface. For comparison, direct shear tests on sand alone were also performed. The results indicate that the sand-geocell interface exhibits higher shear strength than sand alone, while the sand-sheet interface shows lower strength compared to sand. Additionally, the sand-geocell interface shows an interface adhesion of 10.4 kPa. PIV analysis of the sand-geocell interface reveals that the 3D printed geocells follow the general shearing behaviour seen in sand-geosynthetic interfaces, effectively mimicking the shear behaviour of prototype geocells.