Improving the Tensile Strength of 3D-printed Polymer Parts Using the Fused Deposition Modeling by Hot Pressing and Optimizing the Process Parameters

In 3D printing technologies, producing polymer parts with desirable mechanical properties is crucial. The fused deposition modeling (FDM) technique is one of the most common 3D printing processes for manufacturing polymeric parts. However, due to the weak interlayer bonding of the printed parts and consequently inferior mechanical properties, enhancing interlayer bonding is necessary. This study investigated the combination of 3D printing parameters (printing angle) and post-processing via hot pressing (temperature and pressing force). Additionally, the simultaneous optimization of these parameters was conducted to achieve the highest tensile strength in parts made of polylactic acid (PLA). To this end, an experimental design was conducted using the response surface methodology (RSM), and changes in tensile properties concerning the studied parameters were evaluated. The results indicated an interaction between the studied parameters. The optimal values for the raster angle, pressing temperature, and pressure were 90 degrees, 70 degrees Celsius, and 25 N, respectively. Under these conditions, the highest tensile strength of 33 MPa was achieved, showing an approximately 22% increase compared to the initial sample.