Method of forming a molded plastic part

A method of forming an elongate plastic part in a molding operation in which the part is formed by filling an elongated closed mold cavity having a size and configuration conforming to a size and configuration of the elongated plastic part with a plastic material characterized in that the plastic material is extruded to form a moving plastic ribbon and the plastic ribbon is moved into one end of the elongated closed mold cavity to fill the mold cavity, and wherein a cross-sectional area of the extruded plastic ribbon approximates a cross-sectional area of the mold cavity along substantially its entire length so as to maintain a substantially laminar flow of the extruded ribbon of plastic material into the mold cavity until the mold cavity is filled, and wherein the elongated plastic part is formed in the elongated, closed mold cavity.

A method of forming an elongated plastic part including plastic material molded over a substrate characterized in that the substrate is placed in an open mold, the mold is closed to form a closed mold cavity surrounding the substrate with the mold cavity corresponding to a size and configuration of the part being formed and defining a molding space around the substrate, which molding space has a cross-sectional area, a ribbon of plastic material is extruded having a cross-sectional area approximately equal to the cross-sectional area of the molding space and the extruded ribbon of plastic material is fed into the closed mold cavity so as to fill the mold cavity space around the substrate and thus form the elongated plastic part of the plastic material molded over the substrate in the closed mold cavity, and wherein a substantially laminar flow of the plastic material is maintained during the feeding of the extruded ribbon into the closed mold cavity due to the approximately equal cross-sectional areas of the extruded ribbon and the molding space of the mold cavity.

A method of forming an elongated plastic part having a striped surface presenting a texture that contrasts with a texture of a remainder of the part, characterized in that a substrate is formed having a surface including the striped surface, the substrate is placed in an open, elongated mold, the mold is closed to define a closed mold cavity proximate the substrate surface except the striped surface, and plastic material which is formed as an extruded ribbon is moved into the closed mold cavity through a runner in the mold to fill the mold cavity and form a plastic covering over the substrate surface except the striped surface and thus to form the elongated plastic part having the striped surface, wherein cross-sectional areas of the extruded ribbon, the runner, and the mold cavity along substantially its entire length area all approximately equal so that the extruded ribbon of the plastic material moves into and fills the closed mold cavity while a substantially laminar flow of the plastic material is maintained throughout the method of forming the elongated plastic part.