Development of the Numerical Simulation Codes of the Non-isothermal Polymer Processing Containing Melting. Mixing and Kneading Processes That Are Important for the Finished Morphology or Properties of Polymer Products

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The purpose of this research is developing the 2- or 3-dimensional heat transfer and flow analysis programs of non-Newtonian flow with a reaction or viscoelastic flow, which becomes important in a functional polymer material or products developments in polymer processing. The developed simulation programs were applied to various extrusion processes, and the validities were shown by the comparison with experiment data. The main results of this research are summarized as follows ;1. The developed 3-d simulation programs were applied to the melt mixing process in twin screw extruders (TSEs). They show that the experimental data of the pressure and temperature were described comparatively well and prediction of the change of the molecular weight distribution by the reaction in the different kinds of configuration of TSEs was described qualitatively. Moreover, the distributive and dispersive mixings of the 4 kinds of configurations in TSEs were analyzed by the marker tracing procedure with … More the proposed evaluation models. Search of the geometry and the operation conditions of TSEs that attain both the uniform mixture and temperature in a melt mixing region will be possible by these programs.2. The viscoelastic numerical simulation programs show that the reliability of nonlinear viscoelastic models plays important roles on the prediction of the extrudate shape in comparing the practical level's experimental data of the die swell phenomenon in blow molding and a hollow-fiber spinning process, and of the necking phenomenon in a film casting process. Although the useful procedure of controlling the process based on the results from the numerical analysis was proposed, the experimental detail verifications may be required from now on.3. The numerical analysis programs that predict the change of morphology under flow were developed. They show that a remarkably oriented morphology is predicted by the viscoelastic stress in simple shear flow, the particle method is able to describe a deformation and breakup of a droplet and will be possible for describing the unfilled region of TSEs. However, the unsolved problems of the numerically instability, experimental verification in a practical use level, a large amount of calculation cost, and practical modeling of the phenomenon were left behind.As mentioned above, there are some limitations to the developed numerical simulation programs when applying to the practical polymer processing. However, the visualization and analysis of the polymer processing under practical conditions and the proposal of mechanisms that give effective procedures of controlling the process based on the theoretical considerations will be quite useful for an optimization and design of the processing with reducing the conventional experimental trial and error and shortening of material development cost and development period. In future, we would like to advance the applicability of the developed programs in practical level of multiphase flows in polymer processing. Less