A new method to automatically determine parting line in injection mold design

A new method was proposed to automatically determine parting line for molded part which includes undercut features and free form surfaces in the product model. The brief procedure included: 1) simplifying the product model by recognizing the undercut features and transforming the product solid model into the discrete surface model using the finite element method; 2) determining visibility of mesh based on an angle between normal vector of mesh and parting direction, and decomposing complex surface into single surfaces; 3) merging transitional surfaces into visible/invisible surface group based on merge rules and determining parting line by searching the largest edge loop of these two surface groups. Results from demonstration cases show that parting line can be easily determined using this method and efficiency of injection mold design is greatly improved.