Method of and apparatus for molding multi-layer polymer plastic articles having inner, outer and interior or core layers, with control of relative volumetric flow rates of the inner and outer layers enabling relative shifting of the position of the core layer and control of the relative thickness of the inner and outer layers in the molded articles

摘要

A novel technique for molding multi-layer polymer plastic articles having inner, outer and interior or core layers by controlling relative volumetric flow rates of the inner and outer layers to enable relative shifting of the position of the core, and also the relative thickness of the inner and outer layers in the molded articles; and with leading, and, where desired, trailing ends of the interior layer flow into the mold cavity substantially positioned on the zero gradient of the velocity profile of the flowing polymer streams.