Nonuniform Triangular Screw Geometry Enables Distributed Pressure Generation and Improves Process Performance in Industrial Single‐Screw Pet Food Extrusion

This study evaluates a nonuniform triangular screw geometry for pressure distribution and process performance in an industrial single‐screw pet food extruder. Periodic nonuniform channel‐area reductions are hypothesized to induce localized pressure gradients that accumulate axially, enabling distributed pressure generation. Twelve triangular Chronit T‐500 segments replaced the conventional double‐flight mixing screw, eliminating the need for an external back‐pressure valve (BPV). Validation used 1936 records from 6 months of continuous production, analyzed with a quasi‐experimental sequential design. Versus BPV, the triangular screw increased capacity 5.8% ( d = 1.48), reduced die pressure 53.6% ( d = −6.70), increased specific mechanical energy 4.5% ( d = 1.53), and reduced deviation from target bulk density 51%. Variability decreased in five of six indicators. Welch's ANOVA with 95% confidence intervals was used; the effect persisted at production‐lot level. Results are consistent with progressive pressure accumulation through geometrically induced flow restriction, positioning screw geometry as a primary design variable.