The Study On Model Of Homogeneous Solution In Supercritical Microcellular Injection Molding

As a result of the superiority of product and craft, the microcellular plastics obtained the world researchers' attention. The polymer melt/supercritical fluid homogeneous phase solution's rheological property have important influence to product quality and parameters of injection molding process. Therefore it has been the key point in the microcellular injection molding research.This article has mainly studied the change of the polymer melt's viscosity after the supercritical fluid was joined. Analysis the empirical datum to find the temperature and shear rate's influence to viscosity as well as analysis the reason. Analysis the model which uses for the simulation software pore formation analysis module, found the viscosity model in simulation software when uses definition material. Fits the parameter of the Cross-WLF viscosity model through to empirical data, and compared the revision Cross-WLF viscosity model with Cross-WLF viscosity model in the description of polymer melt/supercritical fluid homogeneous phase solution's viscosity. Finally simulate the microcellular foam processing of a thin plate part under different mold temperature, melt temperature and injection speed. And get these three factors'influence to the product's quality. The main work is as follows:First, analyze the mathematical models which were used in molding simulation software's tradition injection molding module and the pore injection molding module.determined which viscosity mode was used in each analysis module. Through the numerical analysis discovered that:What pore injection molding simulation software (Moldflow mucell module) used is the revision Cross-WLF viscosity model (model 1), although can describe the supercritical fluid/polymer melt homogeneous phase solution viscosity, but is unable to reflect influence that the temperature and the shear rate caused; Regarding the pore injection molding simulation from the definition material performance's polymer, discovered there is no difference between the definition material's viscosity model and which is used in the traditional solid injection molding, is unable to reflect influence SCF caused.Second, In experimental result's foundation, has consummated revision viscosity model (model 2) based on viscosity change in the mold die space, this model may describe the temperature and the shear rate's influence to the viscosity, and has compared the model 2 and the model 1.Third, uses two kinds of models to carry on the simulation analysis, and contrastively analysis air bubble size, as well as mold temperature's influence on air bubble size. Through to compare the analysis result based on two kinds of viscosity model with the empirical result we can know which viscosity model is better.Finally, carried on the simulation the simulation of a thin plate under variable mold temperature, melt temperature and flow rate. Contrastively analysis the influence on processes quality when this three parameter varied.