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Shear processing maps: a new design guide for melt processors

Robertson, Ben; Robinson, Ian M.; Stocks, D.; Thompson, Richard L.

Shear processing maps: a new design guide for melt processors Thumbnail


Ben Robertson

Ian M. Robinson

D. Stocks


A method for predicting the optimal conditions for polymer extrusion, which relies only on gramscale laboratory experiments for two commercial polystyrene samples with two molecular weights is demonstrated by oscillatory rheology. These enable a shear viscosity map vs. temperature and shear rate to be constructed, together with the positions for the major molecular timescales. Alternative methods for characterising rheology, including melt flow index and capillary rheology measurements were also employed, but these do not give the same level of understanding of flow behaviour. The capillary tests generates die swell and this complex behaviour can be seen to collapse onto a single line regardless of temperature when plotted using the Rouse–Weissenberg number. The full shear viscosity map, together with the polymer timescales serves as a design tool to predict processing behaviour for melt processors. The work represents and builds on major academic-industry collaborative research programmes.


Robertson, B., Robinson, I. M., Stocks, D., & Thompson, R. L. (2022). Shear processing maps: a new design guide for melt processors. Plastics, Rubber and Composites, 51(5), 217-239.

Journal Article Type Article
Acceptance Date May 7, 2020
Online Publication Date Jul 27, 2020
Publication Date 2022
Deposit Date Aug 3, 2020
Publicly Available Date Aug 5, 2020
Journal Plastics, Rubber and Composites
Print ISSN 1465-8011
Electronic ISSN 1743-2898
Publisher Taylor and Francis Group
Peer Reviewed Peer Reviewed
Volume 51
Issue 5
Pages 217-239


Published Journal Article (Advance online version) (6 Mb)

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Copyright Statement
Advance online version © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted<br /> use, distribution, and reproduction in any medium, provided the original work is properly cited.

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