Abstract: There is disclosed a method for imparting a decorative or printed pattern to the surface of rotationally molded products during their manufacture. In this method, the decorative patterns are formed on a sheet film transfer as a coating of pigments dispersed in a hydrocarbon wax which overlays a release agent, such as a silicone coating on the sheet film. The decorative wax pattern is applied to a preselected area of an inside wall of the rotational molding cavity by positioning the transfer against the surface of the wall and burnishing the pattern onto the interior wall of the mold cavity. Thereafter, the particulate molding resin is charged to the cavity and the product is molded in a conventional procedure, resulting in transfer of the pattern as pigments incorporated into the resin, with most of the wax surfacing and being excluded from the product.

Abstract: There is disclosed a method for the imprinting and decorating rotomolded products. The method comprises the application to the interior surfaces of the mold of a viscous suspension of pigment in a preselected pattern. The suspension is applied to the mold surface in an oil carrier using a vegetable, animal or mineral oil that is inert under the molding conditions and that has a sufficient viscosity at the molding conditions to maintain the film on the mold surfaces. The pattern of the pigment suspension is applied by spraying, brushing, screen printing and the like and, after its application, the conventional rotomolding can be practiced. In this method, the powdered plastic, typically high density polyethylene, in powder form is charged to the mold, the mold is closed and placed in an oven heated to from 500.degree. F. to about 800.degree. F.