Abstract: Aspects of the disclosure are directed to methods and apparatus involving the extrusion of polymers or other materials. As may be implemented in accordance with various embodiments, a polymer is delivered into an inlet of a nozzle structure having the inlet and an outlet. The polymer is viscously heated and melted by rotating the nozzle structure about an axis extending through the inlet and the outlet, therein facilitating extrusion of the melted polymer through the nozzle structure outlet. A polymer supply may deliver the polymer into the nozzle structure inlet, and a coupler may facilitation rotation of the nozzle structure. A driver may further operate to control rotation of the nozzle structure relative to the coupler, for instance by generating a rotational output that causes rotation of the nozzle structure.

Abstract: A method for simulating a fiber orientation in an injection-molded part made of a fiber-reinforced plastic. An orientation of the fibers in the injection-molded part to be manufactured that is present after the injection molding is determined via a macroscopic simulation of the injection molding. The macroscopic simulation of the injection molding takes place using macroscopic physical parameters of the fiber-reinforced plastic. In the macroscopic simulation, a temporal development of the fiber orientation tensor is determined via a combination of two macroscopic models. A first temporal development of the fiber orientation tensor is determined via a first macroscopic model based on shear flows. A second temporal development of the fiber orientation tensor is determined via a second macroscopic model based on elongation flows. The method is applied in a method for designing an injection-molded part made of a fiber-reinforced plastic.

Abstract: Aspects of the disclosure are directed to methods and apparatus involving the extrusion of polymers or other materials. As may be implemented in accordance with various embodiments, a polymer is delivered into an inlet of a nozzle structure having the inlet and an outlet. The polymer is viscously heated and melted by rotating the nozzle structure about an axis extending through the inlet and the outlet, therein facilitating extrusion of the melted polymer through the nozzle structure outlet. A polymer supply may deliver the polymer into the nozzle structure inlet, and a coupler may facilitation rotation of the nozzle structure. A driver may further operate to control rotation of the nozzle structure relative to the coupler, for instance by generating a rotational output that causes rotation of the nozzle structure.

Abstract: In a method and apparatus for micropelletization of a polymeric material, a melt thread of the polymeric material is formed by an extruder. A flowing gas is directed to the melt thread to form Rayleigh disturbances in the melt thread and break up the melt thread into discrete microdroplets. The discrete microdroplets are then solidified to form micropellets.

Abstract: In a method and apparatus for micropelletization of a polymeric material, a melt thread of the polymeric material is formed by an extruder. A flowing gas is directed to the melt thread to form Rayleigh disturbances in the melt thread and break up the melt thread into discrete microdroplets. The discrete microdroplets are then solidified to form micropellets.

Abstract: A screw extruder (10) having a barrel (18) which has a bore (26) defining an inner surface (44) and one or more extruder screws (28), positioned within the bore (26). The extruder screw or screws (28) include a central shaft (34) and one or more screw flights (30). The extruder screw or screws (28) farther including one or more dispersive mixing elements (204), (234), (308), (406), (508), (558), which interact with the inner surface of the barrel (44) to form one or more progressively narrowing passages (46) through which material is forced into multiple regions of high elongational and shear stress (480, (120), (214), (310), (410), (510), (564).A second preferred embodiment is a screw extruder (10) having a barrel (18) having a bore (26) defining an inner surface (44) and one or more extruder screws (600), (701), positioned within the bore (26).

Abstract: A static mixer head that provides not only distributive mixing, but also dispersive mixing. Distributive mixing is accomplished by providing a series of baffles along the length of the mixing tube, each baffle being angled relative to the previous baffle. Dispersive mixing is accomplished by utilizing baffles that define a converging pathway for the mixing materials. The converging pathway promotes elongation and corresponding dispersion of the mixing materials. In one embodiment, the baffles are teardrop-shaped, and are arranged so that multiple baffles are generally parallel and adjacent to one another. Preferably, the baffles are oriented such that the mixing materials flow from the small tail portion of the baffles toward the larger head portion of the baffles, thereby encountering a gradual compressive force and corresponding elongation.