Additive Manufacturing (AM) interest has been growing for the last years due to the capabilities brought by technological evolutions. Nowadays, AM processes offer the possibility to use a huge variety of materials to simply and rapidly create 3D parts, with specific geometries difficult or impossible to obtain with conventional processes [1]. In the same way than for conventional polymer processing technologies, appropriate material grades and associated processing parameters have to be chosen appropriately [2]. Commonly, the adequate process parameters are adjusted thanks to a parametric study, which consumes times and materials. In this work, a novel approach based on the understanding of three main physico-chemical phenomenon occurring during the manufacture of 3D parts (diffusion of polymer chains, coalescence between adjacent rasters and polymer crystallization) was developed and applied to compare several grades of PolyPropylene (PP). Process conditions were simulated thanks to rheological and calorimetric experiments to study the influence of the manufacturing chamber temperature on the kinetics of these three phenomena. The comparison of the three kinetics revealed that for the majority of the tested PP grades, the manufacturing chamber should be heated at a temperature higher than 80°C to favor the polymer chains diffusion and coalescence between adjacent rasters before the polymer crystallization, which is an absolute condition to realize quality 3D parts. [1] M. Attaran, Bus. Horiz.,60, pp. 677-688, 2017. [2] O. A. Mohamed et al. Adv. Manuf., 3, pp. 42–53, 2015.