Abstract: In this paper， an opposite type of bi-color stacking injection mold was designed for a bi-color grille mask of a certain car. The bi-color mold was composed of two pairs of sub-mold， which were installed back to back. The moving part of the two sub-moulds was fixed on the central-rotating platform. A flip mold structure was adopted for the mold. A transparent part was injection molded for the first color， and then the black part was molded for the second color. This avoids the problem of inclined-top trace lines on the surface A of the transparent part. To ensure that the transparent part was located on the side of the cavity and avoid the plastic part falling off during the rotating process， a rotating-fixing mechanism was designed to clamp the transparent part. Aiming at solving the problem of buckle of black part， a slider mechanism and an inclined-top core-pulling mechanism were designed to accomplish the demolding of the buckle area. The bi-color mold can run stably and reliably according to practical verification to meet the requirement for production.

Key words: grille mask, opposite type, bi-color stacking mould, flip mould, rotating-fixing mechanism