Polymer melts, analysis

Spatially Correlated Dynamics in a Simulated Glass-Forming Polymer Melt Analysis of Clustering Phenomena. 

Mitsoulis, E. (2005) Multilayer film coextmsion of polymer melts analysis of industrial lines with the finite element method. J. Polym. Eng., 25, 393-410. 

The flow process in an injection mould is complicated by the fact that the mould cavity walls are below the freezing point of the polymer melt. In these circumstances the technologist is generally more concerned with the ability to fill the cavity rather than with the magnitude of the melt viscosity. In one analysis made of the injection moulding situation, Barrie showed that it was possible to calculate a mouldability index (p.) for a melt which was a function of the flow parameters K and the thermal diffusivity and the relevant processing temperatures (melt temperature and mould temperature) but which was independent of the geometry of the cavity and the flow pattern within the cavity. 

The EMT analysis indicated that the stress relaxes in proportion to the number of bonds removed. The initial linear decrease of E/Eq with is intuitively appealing and is the basis for many linear constitutive theories of polymers. An example is the Doi-Edwards theory of viscoelasticity of linear polymer melts [49] in which... 

Analysis of polymer melt flow High pressure... 

However, for the high strain rates appropriate for the analysis of typical extrusion and injection moulding situations it is often found that the simple Power Law is perfectly adequate. Thus equations (5.22), (5.23) and (5.27) are important for most design situations relating to polymer melt flow. 

When the polymer melt emerges from a die with a rectangular section there will be swelling in both the width (T) and thickness (H) directions. By a similar analysis to that given above expressions may be derived for the swelling in... 

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