Method for the production of sealing elements on plastics articles. Said method includes the step of producing a film of silicone rubber on the sealing surface of the article. Advantageously, this film is formed by co-moulding or co-extrusion with the plastics article itself. The thickness of the said film may vary from a few tenths of a millimeter to a few millimeters. In the case of cylindrical elements, such as the pistons of the delivery cocks of ice cream machines, this film preferably covers only the side wall or the sealing part of the side wall of the cylindrical element, while in the case of flat elements, this film covers only the sealing surface of this element.