Abstract: The present invention is directed to an improvement for a fill valve (22) for an aerosol container (10, 30) to provide better sealing capability. The fill valve is made using a flashless injection molding process in which both the mold cavity and molding material are heated to elevated temperatures to significantly improve cross-linking which occurs during the molding process. A backside (22a) of the fill valve now has a recessed portion (56) to facilitate ejection of the valve from a mold so leak paths are not created due to the forces applied to the valve during its extraction from the mold. The recessed portion reduces the amount of material required to make the fill valve and makes the fill valve flexible to aid in providing a good seal against leakage of a propellant from the container after filling.

Abstract: A method of waste-less molding of rubber is disclosed. The method includes, in a first step, providing unvulcanized rubber that forms rubber of a predetermined tensile strength when vulcanized. In a second step, a mold having an injection port and a mold cavity is provided. The injection port and mold cavity are in fluid communication for forming a rubber part within the mold cavity and a sprue connected thereto extending into the injection port. In a third step, the injection port is configured to have a first point of a first cross-sectional area and a second point of a second cross-sectional area wherein the ratio of the first cross-sectional area to the second cross sectional area with regard to the tensile strength of the rubber causes the sprue to fail at the first point prior to failing at the second point when sufficient tensile stress is applied to the part.

Abstract: The present invention is directed to an improvement for a fill valve (22) for an aerosol container (10, 30) to provide better sealing capability. The fill valve is made using a flashless injection molding process in which both the mold cavity and molding material are heated to elevated temperatures to significantly improve cross-linking which occurs during the molding process. A backside (22a) of the fill valve now has a recessed portion (56) to facilitate ejection of the valve from a mold so leak paths are not created due to the forces applied to the valve during its extraction from the mold. The recessed portion reduces the amount of material required to make the fill valve and makes the fill valve flexible to aid in providing a good seal against leakage of a propellant from the container after filling.