Solid conveying in vane extruder for polymer processing: Effects on pressure establishment

Abstract

The pressure establishment in the solid conveying section of a vane extruder was theoretically and experimentally studied in the present article. Based on the structural and conveying characteristics of the vane extruder, a four‐plate model was developed. The effects of the device geometry (eccentricity ε and discharge port β), the polymer properties (different materials), and the operating conditions (temperature and rotating speed) on the pressure were also studied using a visual experimental device. The results showed that the experimental data were highly consistent with the theoretical data, which indicated that the theoretical model was sensible. Considering the optimization design of the device and its processing parameters, the eccentricity ε and the discharge port β of the discharge baffle should be appropriately selected, and the setting temperature of the feeding section should be set to a low value. The rotating speed of the rotor had no significant influence on the pressure establishment. In addition, the thermo‐mechanical history of the vane extruder was shorter than that of the conventional screw extruder. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers

Poly(lactic acid)/polypropylene and compatibilized poly(lactic acid)/polypropylene blends prepared by a vane extruder: analysis of the mechanical properties, morphology and thermal behavior

“…Polymer materials are fed into the chamber when the volume is large, then ground and compacted. Subsequently, the polymer materials melt and are discharged from the die, completing a plasticizing and positive displacement conveying process based on elongational rheology in a short thermo-mechanical history [31] .…”

Total Strain of Newtonian Fluids in a Vane Extruder

“…Moreover, to reduce the discharge fluctuation, the locations of the vanes are changed by an angle of 45 degrees in two adjacent VPCU. [14] The materials in the vane extruder suffer an elongation stress that is much larger than the shearing stress in the extrusion process. Therefore, it is more beneficial to the dispersive mixing of polymer melts.…”

“…One of the current authors [11] designed a novel equipment and method which is completely different from the conventional screw extruders and produces elongational deformation in polymer processing, the vane extruder, which is constituted by a number of vane plasticizing and conveying units (VPCU). At present, a number of reports [12][13][14][15][16] have been dedicated to the study of the resulting elongational flow. Furthermore, Qu et al [17,18] have proved that a vane extruder can cause a material to undergo large elongational deformation and has better efficiency of disperse mixing by numerous experiments.…”

Solids conveying in the solids compaction zone of vane extruder

“…Figure 1 shows the structure schematic diagram of the vane extruder, which is composed of a rotor, stators, vanes, and baffles. And the vane extruder is separated by the baffle into several VPCUs (vane plasticating and conveying units) in the axial direction of the rotor, more details about this equipment were given by Qu et al [12]. Figure 2 shows the cross-sectional diagram of the solids compaction zone in the first VPCU of the vane extruder, and one chamber filled with polymer particles is chosen to explore the solids conveying mechanism in compaction process.…”