US Patent 7754133 Rotational molding process and product using separation sheet

A product and method where a multi-colored product is rotationally molded with no or essentially no blending of the colors. A separation sheet is positioned in the mold to separate relatively adjacent portions of the mold cavity that contain differently colored resins. The separation sheet acts as a barrier to prevent the differently colored resins from blending during the molding process. During the molding process, the molten resins may fuse to opposite sides of the separation sheet, or the separation sheet may melt and disperse, all or in part, within the mold while maintaining a distinct color difference between the differently colored portions of the molded product.