Multilayer window lift rail, and apparatus and method for making the same

A multilayer window guiderail, comprising:

• a rail portion having an outer edge positioned between a rail surface and an opposing rear surface, the rail portion being further defined by a core having an exterior surface covered with an integrally formed rail cover layer disposed on the exterior surface of the core, wherein the core is a first filled polymer material and the rail cover layer includes a second unfilled polymer material and wherein the first filled polymer material has a first coefficient of friction (μ1) and the second unfilled polymer material has a second coefficient of friction (μ2), and wherein μ1>μ2, wherein the core comprising the first filled polymer material and the rail cover layer comprising the second unfilled polymer material are integrally formed to each other in an injection molding die, with a first injection nozzle and a second injection nozzle, the first injection nozzle configured for injection of the second unfilled polymer material, the second injection nozzle configured for injection of the first filled polymer material, and
• wherein the first injection nozzle has a first lateral spacing from a surface of the injection molding die defining the outer edge of the rail portion and the second injection nozzle has a second lateral spacing from said surface of the injection molding die defining the outer edge, and wherein the first lateral spacing is less than or equal to the second lateral spacing.