An air bag cover
assembly comprises a flexible plastic air bag door closing an air bag deployment opening in a hard plastic
retainer. A door outer edge abuts and is mechanically locked to an inner edge of the opening. The
interlock comprises a protrusion in the door outer edge, which mates with a complementary recess in the inner edge of the opening. The
interlock blocks outward and inward air bag door movement. The door and
retainer are made of plastics, which generally do not adhere easily to one another.
Silicone may be sprayed on the door outer edge to further reduce adhesion or where plastics, which generally adhere to one another, are used. Preferably, the exterior and interior surfaces of the door and
retainer lie flush with one another. The door includes a flexible hinge
flange that extends from an interior door surface and attaches the door to the vehicle structure. The hinge
flange allows the door to swing outward upon air bag deployment while retaining the door to the vehicle structure. A steel door insert may be included to add rigidity, strength or dimensional stability to the door. The
assembly is constructed by molding molten retainer material in a mold cavity that contains the door so that the retainer material flows around the door to form the mechanical
interlock.