A novel deposition strategy to reduce porosity and enhance density in material extrusion production

One of the main issues of Material Extrusion (MEX) production is represented by the porosity of the printed structures. This is strictly related to the deposition strategy which affects the dimensions and the continuity of the porous pattern in the inner part of the components. Having control of the porous patterns allows not only to obtain parts with fewer imperfections but also to improve the mechanical characteristics of the components. In this article, a new deposition strategy is presented which, instead of depositing equal layers, alternates deposition by distinguishing between even and odd positions of the filaments in the layer. Considering the section of the components, the new strategy can reduce the porosity by disrupting its pattern. This results in obtaining a greater number of porosities characterized by a smaller extent, and in a disintegration of the porous pattern, revealing numerous closed porosities. In general, the developed strategy allows the increment of the apparent density.