Abstract: A device and method for molding a plastic component, comprising a slide movable in a translational movement between a position in which the slide is open and a position in which the slide is closed, the slide comprising a cold runner opening into the molding cavity and the device comprising an ejection member for ejecting plastic sprue formed in the cold runner. The ejection member comprises at least two parts, the first part being borne by the mobile part and the second part being borne by the slide, the slide being movable between a position in which the two parts of the ejection member are offset and a position in which the two parts of the ejection member are more or less aligned so that they can collaborate with one another. The molding cavity comprises a region intended to form a rib or a tab of the plastic component, the cold runner opening into this region.