One-Dimensional Melting Model

The film at the start of the melting process has an initial thickness estimated from Eq. 6.13. As the solids continue to melt, the film thickness at the barrel solid bed interface increases slightly and decreases the dissipation because the local shear rate decreased. Since the dissipation decreases, the melting rate also decreases. This theory requires the solution of only two coupled differential equations  

In this simulation the model assumption is that the melt film is transported into the pores of the bed. Thus the melt film is relatively thin even for this mechanism due to the reducing depth of the channel. The model as developed does not account for any conductive heat transfer into the solid particles from the liquid infiltrate. For most extrusions, the center of the solid bed may be porous while the edges exposed to the melt film are not. The sealed edges prevent the melt from infiltrating the solid bed and the melting process occurs via conventional melting. Conventional melting was observed for the case with the measured bulk density data in Fig. 4.1. 

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