Morphology Development And Performance Study Of The Polymer In The Single Shaft Vane Extruder

During real polymer processing, it is dynamic factor, but not only thermodynamic factor, that has more direct effection on polymer structure. Single vane extruding machine is a new type of polymer processing device, which is invented by Qu Jinping , Professor of South China University of Technology. Its processing course is just the same as that of screw, firstly, polymer has been melted by heat, secondly, covered by external force field, it has been transforming, flowing and mixing, and then, been given some certain shapes. The difference between them is the types of external force fields, which would cause material properties of micro and microscopic different.By using method of static quenching sampling, the author picks HDPE as the main material, take samples along the srew of vane extruding machine, according to the order of extruding process, then, has investigated the HDPE melting and mixing performance that from inlet to discharging die in the vane extruding machine. The specific research process shows as follows: 1) choose HDPE/color masterbatch as carrier, extrude it at different rotational speeds and die pressures, take samples after quenching, analyze melting and mixing performance of HDPE in single vane extruding machine, in micro-scale. 2) choose PS/HDPE, extrude it at 75r/min, take samples after quenching, analyze melting and mixing performance of HDPE/PS in single vane extruding machine, in microscopic-scale. Tesing samples that been taken from circumterential and axial directions in different vane units, we understand the material morphology varieties in extruding process.The results indicate that: There is no solid conveying section in the vane extruder, from the first vane unit, material has been melting, and has been through intensive extruding deformation. At the condition that the rotation speed is lower than 75r/min, the length of melting section would be longer and melting speed would be faster, while at the condition that the rotation speed is higher than 75r/min, the length of melting section would be the same as before; the pressure of die has little influence on material.In the vane extruding machine, with the increasing of vane units amount, dimensions of dispersion phase HDPE/PS blend has continuously refined, interphase void has continuously diminished, however, bond force has continuously reinforced, it is vane units that has obvious extention effect, especially at the end of compression zone. In the vane unit, Dispersion phase has been through a process that from spheroidicity to cylinder ,and then to silk ,at last to liguid-drop.Vane unit has forced refining effect on the materials, which speed up its melting and dispersion.