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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