An extruder screw for plasticizing at least one plastic or plastic mixture, including a melting zone, a shaft zone and a mixing zone arranged between the melting zone and the shaft zone, wherein a conveying flight is formed in the melting zone and in the shaft zone, which extends helically along a longitudinal axis of the screw, wherein a conveying flight of the melting zone ends at an end of the melting zone towards the mixing zone and a conveying flight of the shaft zone begins at an end towards the mixing zone. A flight depth of the melting zone continuously decreases along the longitudinal axis of the screw to the mixing zone. Further, an extrusion device having the extruder screw and to a method for plasticizing at least one plastic or plastic mixture.

An extruder has a barrel extending from a feed inlet end to an extruder outlet end. The barrel has an inner surface, an outer surface, and a wall thickness between the inner and outer surfaces. The extruder also has at least one heating member positioned provided on the barrel; a screw drive motor drivingly connected to a rotatably mounted screw positioned within the barrel, whereby the screw is rotatable at various revolutions per minute (RPM); and a controller is operably connected to the screw drive motor to adjust the RPM of the screw based upon a temperature of material passing through and/or being extruded from the barrel. Methods for operating an extruder filling a mold are also provided.

In an extrusion molding apparatus according to an embodiment, a control unit configured to perform feedback control for a rotation speed of a pump so as to bring a pressure measured by a pressure sensor closer to a target pressure determines a current state and a reward for an action selected in the past based on a difference between the measured pressure and the target pressure, updates a control condition, which is a combination of a state and an action, based on the reward, selects an optimum action corresponding to the current state under the updated control condition, and controls the rotation speed of the pump based on the optimum action.

A mixing and extrusion machine (10) for the manufacture of rubber mixtures includes a mixer with a converging conical twin-screw (12) with a fixed frame (14) that supports sleeves (16). Two screws (18), being mounted at an angle, are mounted in the mixer (12) in such a way as to move in translational movement between an opening (22) arranged upstream and an outlet (25) arranged downstream of the sleeves. The screws are mounted in the sleeves with removable doors including sliding shutters (40) installed relative to the outlet (25). The sliding shutters move linearly between a closed position, in which the sliding shutters prevent the mixer from discharging the mixture, and an open position, in which the sliding shutters prevent discharge of the mixture through the sides of two counter-rotating rollers (32) of a roller nose type system located just downstream of the outlet.

A mixing and extrusion machine (10) has a converging conical twin-screw mixer (12) with a fixed frame (14) that supports sleeves (16) in which two screws (18) are mounted at an angle between an opening (22) arranged upstream of the sleeves, where an introduction hopper (24) of the machine (10) feeds the screws, and an outlet (25) arranged downstream of the sleeves, where the mixer discharges the mixture at the end of a mixing cycle. At least one mobile sleeve (34) is disposed towards the outlet, each mobile sleeve with a support surface (34a) of a predetermined surface area (34a) according to an elasticity of the mixture, and each mobile sleeve having one or more mobile elements that move by a linear movement with respect to the outlet in order to adjust a predetermined space between the sleeves and the screws.

An extruder for polymeric materials, includes: a hollow extrusion cylinder, having an inlet for receiving pellets of polymeric material, and an outlet for expelling molten polymeric material; an extruder screw connected to a motor to rotate inside the extrusion cylinder and to move the polymeric material from the inlet to the outlet; heaters coupled to the extrusion cylinder; a sensor system configured to measure values of a recipe parameter and of a monitoring parameter; a processing unit, programmed to store a target value for the recipe parameter and to perform a feedback control to bring the recipe parameter to the target value and to keep it at the target value.

A method of manufacturing a polymer film includes melting a resin, extruding the melted resin through a die to produce a polymer film, shaping the polymer film, cooling the polymer film, capturing an image of a test pattern through the polymer film, calculating a modulation transfer function value from the image, and adjusting a process parameter of the melting, the extruding, the shaping, or the cooling based on the calculated modulation transfer function value.

A method of manufacturing a polymer film includes melting a resin, extruding the melted resin through a die to produce a polymer film, shaping the polymer film, cooling the polymer film, capturing an image of a test pattern through the polymer film, calculating a modulation transfer function value from the image, and adjusting a process parameter of the melting, the extruding, the shaping, or the cooling based on the calculated modulation transfer function value.

An extruder configured to extrude a solid raw material containing moisture includes a barrel, a hopper coupled to one side of the barrel, a discharge port, a screw, vent disposed between the hopper and the discharge port to discharge vapor generated within the barrel; and a heater mounted on the barrel to heat the raw material. Raw material introduced into the barrel through the hopper is heated by the heater while being transferred within the barrel through the screw. A kneading zone, in which raw materials transferred by the screw threads are compressed, is formed on the screw. Since the raw material is melted within the barrel, a heating temperature of the heater and an axial rotation speed of the screw are controlled so that a sealing membrane that shields an inner transverse section of the barrel is formed from the liquid raw material in the kneading zone.

Disclosed herein are three-dimensional porous tubular scaffolds for cardiovascular, periphery vascular, nerve conduit, intestines, bile conduct, urinary tract, and bone repair/reconstruction applications, and methods and apparatus for making the same.