Meaning
Tooling efficiency metrics express the ratio of net usable part volume produced by a multi-cavity injection mold relative to total melt volume delivered per machine stroke. Maximizing volumetric cavity yield reduces material waste associated with sprue systems and runner channels in multi-cavity tooling. High yield percentages indicate that nearly all polymer displaced by the injection screw forms saleable component geometry.
This metric marks the practical boundary between high-efficiency hot runner molds and cold runner systems that generate high regrind volumes.
Mold Efficiency
Hot runner valve gate technology eliminates cold runner scrap, bringing volumetric cavity yield close to theoretical upper limits. Cold runner molds require regrind granulators to reprocess runner trees, introducing contamination risks and thermal history degradation into future production lots. Calculating cavity yield helps tooling engineers justify higher initial capital investment for hot runner systems against long-term resin savings.
Production Offset
Imbalanced runner layouts cause uneven filling rates across outer and inner mold cavities. Cavity volume discrepancies force operators to overpack full cavities while underfilling distant cavities, lowering net acceptable part yields per shot.
Tooling Yield
Wear on cavity shut-off surfaces generates flash that consumes excess melt volume without contributing to part functionality. Regular mold maintenance and precise parting line venting protect effective volumetric cavity yield over extended production campaigns. Monitoring total resin consumption against finished part weight verifies tooling performance across high-volume production schedules.
