Numerical and experimental analysis of a flame-retardant polymer material after extrusion through the printing nozzle of fused filament fabrication system.

Research focuses on developing a novel flame-retardant filament utilizing acrylonitrile–butadiene–styrene (ABS) and ammonium polyphosphate (APP) by the numerical approach using finite element analysis (FEM)-based software, COMSOL Multiphysics to overcome nozzle clogging and establish optimal three-dimensional (3D)-printing parameters. The developed FEM model enabled the numerical testing of differently shaped nozzles and proven the benefit of using a low-convergence angle (60°) nozzle because of the greater magnitude of pressure drop at nozzle tip compared with that of a high-convergence angle (120°) nozzle, a slightly better temperature distribution at the nozzle region, and smoother flow of the melted filament. Experimental tests results demonstrated the feasibility of using fused filament fabrication 3D printing to apply on ABS composite directly, and the printed samples retain their properties. An improvement in the burning test showed a V₀ rating, thermal stability 13% at 800 °C, and the heat release rate of ∼390 W/g compared with neat ABS (∼501 W/g). [ABSTRACT FROM AUTHOR]