摘要:
Improved, high Specific Mechanical Energy extrusion systems (20) are provided including a single or twin extruder (22) and an upstream preconditioner (24). The extruder (22) includes an elongated barrel (26) with at least one elongated, axially flighted, rotatable screw assembly (58) therein. The barrel (26) includes a mid-barrel variable restriction valve assembly (32), and the screw assembly (58) has a disrupting/homogenizing screw section (66) therein upstream of the valve assembly (32). The screw section (66) includes a plurality of alternating pitch screw parts (82-92). Preferably, the barrel (26) also has an atmospheric vent (36) downstream of the valve assembly (32).
摘要:
Described is a method for dissolving PPTA or copolymers thereof in sulfuric acid using a twin screw extruder having transporting, mixing, and kneading elements with an entering zone, an intermediate zone, a mixing zone, a negative transport zone, a degassing zone, and a pressure build-up zone. The method includes transporting PPTA or copolymer thereof into the entering zone at a transport capacity low enough as to prevent sulfuric acid entering the entering zone; introducing sulfuric acid in the intermediate zone; essentially fully filling the mixing zone to allow sufficient time to mix and dissolve PPTA or copolymer thereof in the sulfuric acid to obtain a PPTA or copolymer-sulfuric acid solution; creating after the mixing zone a negative transport zone to obtain a product lock between the mixing zone and the degassing zone; creating a thin film of the PPTA or copolymer-sulfuric acid solution in the degassing zone to degas the solution; and entering the solution into the output pressure build-up zone to partially fill this zone and to leave the twin screw extruder.
摘要:
A screw extruder comprises an extruder body (4) with a bore (4H), and a screw (5) rotatably disposed in the bore (4H). The screw (5) comprises a screw shaft (7) and two screw flights (8 and 9) disposed in the form of a double helix. The screw flight (9) is substantially continuous, but the screw flight (8) is provided with large interruptions (11) within which a plurality of additional flight pieces (13) are disposed to change the number of passages repeatedly. Mixing/kneading pins (15) protruding into the bore (4H) can be provided. Preferably, the paths (17) for the mixing/kneading pins (15) are positioned within the interruptions (11) and on the upstream side and downstream side of the additional flight pieces (13).
摘要:
A screw 12 for an extruder 10 rotatably supported on the cylinder of the extruder and carrying roll-heated rubber material supplied from a hopper port 13s provided at the rear part of the cylinder 11, wherein the height of the portion of the flight portion 12z of the screw 12 located below the hopper port 13s is set lower than the height of the flight portion 12a on the downstream side of the screw 12, whereby the pulsation of extruded matter can be reduced while maintaining a high discharge rate.
摘要:
An apparatus for manufacturing moldings by which clear colors and patterns can be brought out without a remarkable lowering of strength. Immediately before delivery to a metal mold, outer resin material positioned on the main cylinder inner wall side is put in the molten state, and inner resin material positioned on the main screw side is controlled to be from the softening temperature to the melting temperature both inclusive to be extrusion-molded as they are. The inner wall of the main cylinder is expanded where the outer resin material is received to help the outer resin material be thrown in smoothly.
摘要:
A thermoplastic extrusion assembly having a melt region wherein a plurality of material pellets are melted and mixed by a mixing assembly with a foaming agent, in the case of a thermoplastic foam extrusion assembly, introduced via an agent addition assembly. The thermoplastic extrusion assembly further includes a heat extraction region structured to extract excess heat from the mixture of melted material pellets such that the mixture achieves an extrudable temperature. The heat extraction region includes an elongate barrel having at least one inlet and at least one outlet, the inlet being structured to receive the extrusion mixture therethrough for passage into the barrel wherein a heat extraction structure cooperatively disposed with the barrel draws heat therefrom. An extrusion screw is disposed in the barrel and includes at least one screw flight structured to rotate within the barrel and urge the extrusion mixture towards the outlet of the barrel where a die is disposed in order to form the finished product. Moreover, the screw flight includes at least one circulation channel having an asymmetrical, at least partially inwardly tapered inlet area defined therein and structured to receive quantities of the extrusion mixture therethrough upon rotation of the extrusion screw, thereby circulating the extrusion mixture towards the barrel for more effective and uniform cooling of the extrusion mixture prior to passage through the die.
摘要:
A process and an apparatus for recycling resin scrap including a thermosetting resin paint film and a thermoplastic resin substrate as its major components, wherein the resin scrap is supplied into a passage of a cylinder, melted, and delivered by screw arrays from an upstream side to a downstream side of the passage of the cylinder, and hydrolyzed by a hydrolyzing agent while forming a highly packed region with a resistor. The resistor restricts the resin scrap to flow from the upstream side to the downstream side in a short period of time, and forms the highly packed region where a contact efficiency is enhanced between the resin scrap and the hydrolyzing agent.
摘要:
Each of two screw bodies includes a feed screw and a kneading screw. The feed screw is formed of a wide-flight 1-lobe intermeshing screw designed so that the ratio W.sub.0 /D of the flight width W.sub.0 thereof to the screw diameter D ranges from 0.2 to 0.4. The kneading screw includes a plurality of double tipped kneading discs designed so that the ratio W/D of the width W thereof in the axial direction of the screw bodies to the screw diameter D ranges from 0.3 to 1.0, and displaced from one another in the circumferential direction of the kneading screw, the angle by which any two adjacent kneading discs being displaced range such that at least a backflow of an extrusion material can be prevented.
摘要:
A machine for processing solid and viscous plastic materials includes a screw element having a shearing flight and a scraping flight. Upon rotation of the screw, the shearing flight shears the plastic material and the scraping flight guides the material to the shearing flight. Preferably, the screw includes a plurality of threads which extend from one end of the screw to the other, and which include a plurality of shearing and scraping flights.
摘要:
The extrusion screw for thermoplastic material comprises a helical thread, having a trapezoidal profile with a flat crest and inclined flanks, the pitch and the width or the root of which remains constant, while the inside diameter of the screw increases from the entry of the screw in the direction of the exit.