Adaptive slicing and speed- and time-dependent consolidation mechanisms in fused deposition modeling

Fused deposition modeling involves line-by-line and layer-by-layer deposition of a semisolid polymer, and the material consolidation mechanisms eventually result in a composite of the polymer substrate with interspersed inter-road voids. Considering the potential capability of the process for direct digital production of end-use parts with materials of engineering significance, methods such as adaptive slicing were attempted targeting better part qualities together with improved production times. While adaptive slicing was attributed with several useful qualities, a careful consideration reveals that most of these attempts were mere mathematical approaches, with very little or no theoretical and experimental evaluation of the actual effects. Theoretical models predicting the mechanism of inter-road bonding through solid-state sintering existed for a while, and with the advent of advances made in understanding the inter-road coalescence and mechanism of material consolidation, it is necessary to revisit adaptive slicing and establish the true attributes. This article attempts this through mathematical and experimental evaluation, considering in particular, the time- and speed-dependent variation of the inter-road coalescence.