How does the temperature of polymer bead influence the kinetics of coalescence in additive manufacturing processes?
Résumé
Abstract The quality of a part made by fused filament fabrication substantially depends on the coalescence level achieved between the polymer beads. This paper describes an innovate approach quantifying the influence of the polymer temperature on the coalescence kinetics between two molten polymer beads. The models presented in the literature were modified to introduce two major thermo‐dependents intrinsic characteristics of the polymer, its surface tension and viscosity. The accuracy of the developed model was confirmed by the good correlation between calculated and experimental data. The influence of the polypropylene temperature has been found substantially different for different polymer grades. The results revealed that the change of viscosity influences the coalescence kinetics much more than the surface tension. The developed model is applicable to study the coalescence of any polymer beads in the range of temperatures between the crystallization and degradation temperatures.