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The process for insert molding polycarbonate-based films includes waterbased inks, equipment for registering films in the mold, and a highheat polycarbonate printing ink.
Traditional methods for decorating injection-molded parts include painting, screen printing, pad printing, and hot stamping. Recently, however, alternate decoration methods have been developed that require fewer processing steps and environmental controls. These methods include in-mold foils, insert molding using polycarbonate film, and sublimation heat transfers. Insert molding processes for polycarbonate films include water-based inks, forming methods and equipment for registering films in the mold, and a high-heat polycarbonate printing ink. These materials and processes provide increased design flexibility, recycling, and lower total costs than traditional decorating methods.
CONVENTIONAL DECORATING
One of the more traditional methods of decorating molded parts is pad printing. It uses an engraved metal or photopolymer plate which is doctorbladed with a printing ink.
For the engraved image, brass or bronze is usually used for long production runs, while photopolymer plates are used for shorter runs. The method works for decorating parts with irregular shapes and surfaces. However, one of the primary disadvantages is that the printed image, similar to a painted surface, wears and abrades.
Adhesive-backed nameplates are another method of decorating molded parts. The pressure-sensitive nameplate or label is affixed to the molded part by removing the release liner on the back of the part and physically placing the nameplate on the molded assembly.
Painting the molded assembly with the desired background color and printing the graphic legend directly on the molded surface using screenprinting techniques can also be used to decorate molded parts. But, because screen printing inks are forms of paints, they are subject to the same wear and abrasion concerns as painted surfaces.
NEW DECORATION METHODS
Several new methods of decorating molded parts are in the works. Designers are looking for new methods to make their products stand out. Also, they want methods that increase productivity and design freedom, and can be recycled.
Two technologies that could achieve these goals are in-mold decoration and insert-mold decoration. Though these terms are often used interchangeably, they are distinctly different methods with their own strengths and limitations.
In-mold decoration places a preprinted carrier, typically a thin polyester film, in an injection mold before resin shoots into...