An injection-molding process and an apparatus for making a multi-component hollow article, and the article made thereby. The process comprises molding, from a first plastic material, a hollow body having a wall with at least one vent therethrough and at least one flap molded in an area adjacent to the vent. The flap is molded in a first position in which the vent is open. The flap is hingedly movable from the first position to a second position in which the vent is closed by the flap. After the flap is folded into the second position, the hollow body, including the folded flap, is at least partially overmolded with a second plastic material, wherein the second material is essentially precluded from leaking into the hollow body through the vent. The apparatus comprises a first mold bar for molding a hollow body, a second mold bar for overmolding the hollow body with a second plastic material, and a closing tool for moving, and optionally retaining, the flap in the second position. The resulting article has no second material inside its hollow body.