A self-cleaning extruding apparatus with two co-rotating screws and the method thereof are provided here. Said apparatus is comprised of a screw mechanism, a barrel (1), a feeding port (10), a venting port (11), and a discharge port (12). Said screw mechanism is comprised of the first screw with one tip (3) and the second screw with two tips (4). There is a baffle in the channel of the first screw and the baffle's height is lower than that of the screw flight. The baffle will cause hyperbolic perturbation in the shape of a ‘figure 8’ flow pattern above the top of the baffle. The first and second screws rotate at the same speed and touch each other at all times, thereby achieving a self-cleaning function.

The baffle will generate chaotic mixing in the screw channel caused by the hyperbolic perturbation. Topological chaos is also introduced into the screw channel by the mechanism ‘one part divided into two parts, then two parts converging into one part, and then one part divided into two parts once more’. Each of the screws in the present invention uses an asymmetrical flow channel geometrical shape, such that a periodic action like ‘compression—expansion—further compression—expansion further’ works. The above three enhancement mechanisms work together to efficiently accelerate melting and mixing.

A screw element (100) for an extrusion machine is provided. The screw element (100) includes a first section (200) and a second section. The first section (200 has a first core (212) with a plurality of facets (214) connected to each other along splines (216). The facets (214) and splines (216) extend longitudinally along the screw element (100). The facets (214) and splines (216) can be helically-shaped. The first core (212) increases in diameter in a continuous manner along the direction of flow of material. The first and second sections (200, 300) include one or more helically-shaped flights (218,219) wrapped around the longitudinal axis of the screw element (100).

An extruder, such as a double-screw extruder includes a double cylinder and a double-lead screw arranged therein with a drive train for the screw. The drive train has a coupling with the screw. The extruder includes a sensor for recording a moment load having torque and/or bending moment and for generating electronic data from the recorded moment load. A controller is provided in operative connection to a drive for the drive train and the sensor is in data connection with the controller. The controller is adapted to evaluate the data on the recorded moment load and to trigger a protective action if a threshold value set in the controller is exceeded. The evaluation includes a bending moment calculation. A plastic molding plant produces a film with the extruder along with a nozzle unit and a cooling and wind-up unit or a compounding plant. A method for operating such a plant for manufacturing a film includes the extruder.

The invention relates to an apparatus for the pretreatment and subsequent conveying or plastification of plastics, with a container with a mixing and/or comminution implement that is rotatable around an axis of rotation, wherein, in a side wall, an aperture is formed, through which the plastics material can be removed, a multiscrew conveyor being provided, with at least two screws rotating in a housing, wherein the imaginary continuation of the longitudinal axis of the conveyor in a direction opposite to the direction of conveying passes the axis of rotation, where, on the outflow side, there is an offset distance between the longitudinal axis of the screw closest to the container and the radius that is parallel to the longitudinal axis, and in that the two screws closest to the intake aperture are counter-rotating relative to one another.

The invention relates to a process for extruding plastic compositions. The process in particular relates to the conveying, kneading and/or mixing of plastic compositions, in particular of polymer melts and mixtures of polymer melts, above all thermoplastics and elastomers, particularly preferably polycarbonate and polycarbonate blends, also with the incorporation of other substances such as for example solids, liquids, gases or other polymers or other polymer blends.

The invention relates to a mixing device for a twin-screw extruder, in particular a twin-screw extruder rotating in the opposite direction, comprising a first screw and a second screw, for mixing a melt flow in a screw antechamber, wherein the first screw has an extension in the form of a mixing screw tip connected to the first screw in a fixed manner, and a first melt channel, into which the first screw feeds, is arranged in a flow-connected manner via an elongated slot with a second melt channel, into which the second screw feeds.

Provided is a thermoplastic elastomer composition capable of producing a molded article having a good appearance such as surface smoothness and excellent bondability to another member, the thermoplastic elastomer composition comprising: an ethylene-based polymer (A); and a propylene-based polymer (B), wherein a melt viscosity of the thermoplastic elastomer composition measured at a temperature of 220° C. and a shear rate of 12 sec.sup.−1 is 2,500 Pa.Math.sec or less; the thermoplastic elastomer composition has a sea-island structure; and an island portion has a volume average particle diameter of 2.1 μm or more and a particle diameter dispersion D of 7.0 or less.

Provided is a thermoplastic elastomer composition capable of producing a molded article having a good appearance such as surface smoothness and excellent bondability to another member, the thermoplastic elastomer composition comprising: an ethylene-based polymer (A); and a propylene-based polymer (B), wherein a melt viscosity of the thermoplastic elastomer composition measured at a temperature of 220° C. and a shear rate of 12 sec.sup.−1 is 2,500 Pa.Math.sec or less; the thermoplastic elastomer composition has a sea-island structure; and an island portion has a volume average particle diameter of 2.1 μm or more and a particle diameter dispersion D of 7.0 or less.

Screws for a carbonizing machine for carbonizing organic material into useful char product.

Screws for a carbonizing machine for carbonizing organic material into useful char product.