Conclusion
The numerical simulation method of the Hele–Shaw flow in TSE results in
a comparative resin pressure, resin temperature, and degree of fill with
the experimental data examined in a ϕ26 mm self-wiping TSE. The proposed
method enabled us to determine the global calculation of the degree of
fill from the feed to exit of the TSE, which enables us to consider the
design, operation, and maintenance of TSE from the viewpoint of the
degree of fill.
However, there are several limitations to the proposed calculation
method. Our method is limited to the application of the self-wiping
co-rotating screws; further, the flow through the intermeshing region is
neglected. Thus, the proposed method cannot be used for a
counter-rotating TSE. The method is limited to purely viscous
non-Newtonian fluids. Higher molecular weight molten polymers with a
viscoelastic effect, e.g., significant normal stress difference, may
cause a different resin distribution than that in the current
calculation results. Therefore, in a future study, we plan to study of
the relationship between the normal stress difference and the resin
distribution. Even though these limitations exist, we believe that the
proposed method paves the way for the calculation of resin distribution
of entire screws in TSEs. Knowing the resin distribution for the
full-flight screw elements is useful for estimating the surface area of
mass transfer in the devolitilization process of TSEs. The overall
calculation of the resin distribution, which enables us to know the
details of the distribution of the strain rates and shear stress, is
applicable to the estimation of the glass fiber attrition from the feed
port to the head in a TSE. Our study provides a means of calculation and
experimental results for both devolitilization as well as fiber
attrition that can be applied in further studies.
Acknowledgments
A part of this study was financially supported by The Die and Mould
Technology Promotion Foundation, Japan, and the Tokyo Metropolitan Small
and Medium Enterprise Support Center. We would like to thank Editage
(www.editage.jp) for English language editing.
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