Automated ejectability analysis and parting surface generation for mold tool design

This report describes a CAD approach for automated ejectability analysis and parting surface generation for mold tool design. This design automation is incorporated into a Rapid Tool Manufacturing system which integrates stereolithography (SLA) and thermal spraying into a CAD/CAM environment for manufacturing tooling like injection molds. Design models are first evaluated for part ejectability given the desired draw direction and constrained to be manufactured in a two part mold. This information helps the designer to create manufacturable designs. The parting line and parting surface models are then created subject to geometric and process constraints. The union of part design and parting surface models forms impressions of the mold cavities. Cavity patterns are then quickly built with SLA and the molds are fabricated by spraying metal onto SLA patterns.