A novel regime map for twin-screw melt granulation: Unveiling new insights into key operating variables

Abstract

Regime maps are vital in twin-screw granulation, predicting outcomes via dimensionless numbers. This study develops a novel regime map for twin-screw melt granulation, adapting a wet granulation model. Using Design of Experiments, screw speed, screw configuration, temperature, and binder amount were optimized with lactose and PEG 6000. Results show how these variables impact on particle size and flowability. Optimal conditions (20 wt% PEG, 70 °C, 100 rpm) yielded granules with 0.360 mm median size and 6.67 % Carr Index, indicating excellent flow. Increased binder and kneading elements led to larger granules, while higher screw speed enhanced mixing. Elevated temperatures boosted binder melting. The regime map accurately categorized growth, largely in the breakage-dominated region, and was validated across systems, proving its predictive potential.