| Due to their advantages in application, screw extruders have taken a quite big market in polymer industries. Triangular-arranged triple-screw extruder is another originality of extrusion machine; whose unique extrusion characteristics and running mechanism make it hasing great advantage in such ways as polymer blending, improving performance and high concentrated color batch. Triple-screw extrusive industrial equipment is a new technology coming out in recent years. Although its extrusive characteristics such as energy-consuming, disgregation, exhausting and so on have been tested very well, the flow pattern, blending and mixing mechanisms and the shearing effect of polymer melt in triple-screw are waiting for our in-depth researches.With the upgrade of the computer calculation and the development of finite element package, numerical simulation has become a very important method for in-depth study of the three-dimensional flow in screw extruders. In order to get further understanding of the flow pattern and blending mechanism of the polymer in extruders, following studies are carried out using the finite element package POLYFLOW, as described in this paper.(1) A modal was built with the technology parameters of industrial machine to simulate numerically the three-dimensional isothermal flow in the kneading blocks of triangular-arranged intermeshing co-rotating triple-screw. The overlaping grid method was used to optimize the quality of gridding. Particle tracking analysis (PTA) was used to study the flow fields in intermeshing co-rotating triple screw extruder. The flow pattern and the blending mechanism of polymer were also been studied and the fields of velocity, pressure, shear rate and viscosity for non-Newtonian polymer melts were solved.(2)In order to evaluate the ability of dispersing and blending of triple screw extruder, POLYSTAT was used and the concepts such as accumulated max-shear rate distribution and its probability of distribution of density were introduced to analyze and compare the flow pattern, the residence time distribution and the max-shear rate distribution of polymer. According to description of tracks of tracing particles with different starting points, the multipass exchange of the material in the space of triple-screw extruder was expressed visually.(3)The laminar flow shear theory was used in this paper to calculate the viscous shearing heat and the result of this calculation was contrasted that of twin-screw extruders. Combining the testing data of the practical experiment, the correctness of the method and result were discussed. The calculation of viscous shear heat has some instructive meaning to the rational adjust of the technological temperature and controlled time in screw extruders in order to realize our popurse of energy economizing during the whole extrusive process.
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