Optimization of Adhesively Joined Laser-Sintered Parts

As additive manufacturing technologies are advancing in quality and economic feasibility, joining and assembly is becoming increasingly important for industrial users. In this study, the performance of four adhesives for polyamide 12 specimens is analyzed. Testing of bonding relevant factors, such as the surface energy of the solid substrates, is conducted. Tensile shear tests of plain polyamide 12 specimens glued together, show an early adhesive failure of the joint. To increase the polar bonding forces and the surface energy of the solid substrate, pretreatments such as atmospheric plasma, chemical, corona and flame treatment are applied. An increase up to 81% of the original binding strength can be achieved with flame treatment. As an alternative to increase the bonding strength of the joints, the effects of design changes of the bonding area are looked at. The research shows that micro tubes on the surface of a substrate can increase the bonding strength up to 49%. A summary of the impact of all pretreatments and design changes is given and the suitability of each application is assessed.