Adhesive bonding of similar/dissimilar three-dimensional printed parts (ABS/PLA) considering joint design, surface treatments, and adhesive types

Three-dimensional printing (3D), a vital technological pillar of industry 4.0 suffers from an important bed size limitation, wherein it cannot print any part larger than its bed size. Unfortunately, research in this domain has not kept pace with the other limitations hindering the acceptability of fused deposition modeling (FDM)-3D printers. This paper investigates the adhesive joining of dissimilar 3D-printed parts made from usually preferred materials (Acrylonitrile Butadiene Styrene (ABS), Polylactic Acid (PLA)) having different geometric joint designs (lap, scarf, stepped) employing diverse adhesives (epoxy, cyanoacrylate, polyurathane-based) subjected to different surface treatments (sanding, vapor, plasma). The aim is two-fold: to enhance the joint strength making adhesive bonding a suitable solution for complex structural application, as well as to overcome the bed size limitation of commercially available 3D printers. The individual and combined effect of the parameters, prediction, and validation for tensile strength were realized by statistical tools (DOE and ANOVA). The results revealed the significance of the process parameters in the following order: material type, joint configuration, adhesive types, and surface pre-treatments. The preferred material turned out to be ABS + ABS, with stepped configuration, subjected to plasma treatment and bonded with Loctite adhesives giving a strong improvement in terms of performance. Finally, the model summary with R2 value of 95.6% implied that the experimentation was successful and could be easily reproduced on an industrial scale helping to attain high strength-less weight components even with smaller FDM-3D printers.