Effect of laser micro-texturing MJF 3D printed polymers on surface properties and mechanical strength of adhesive joints

The effect of laser micro-texturing of the surface of PA12 polyamide samples manufactured using the Multi Jet Fusion (MJF) additive method in terms of their surface properties and mechanical strength of adhesive joints was presented in the article. The study identifies a correlation between the surface structure of printed samples and laser processing parameters that enhance adhesion mechanisms during bonding. The results demonstrate that an optimized surface topography enables the creation of durable, high-strength adhesive joints. A grid-type texture with groove depths in the range of 150-200 μm allows for a nearly 50% increase in the surface free energy (SFE) of the prints. It was shown that laser micro-processing allows for obtaining adhesive joints with high shear strength, exceeding 40 MPa, which is more than twice as much as compared to the reference joints in the as-printed state. • Laser micro-texturing of MJF 3D prints boosts adhesion strength in PA12 polyamide adhesive joints. • Grid texture allows for good surface development and increases surface free energy by nearly 50%. • Complete surface melting lowers SFE and peel strength, optimal texture should be in the range of depth 150-200 μm. • Laser-treated samples achieve over 40 MPa shear strength. • Laser micro-texturing enables obtaining durable and strong adhesive joints in elements printed using 3D technology.