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Frontiers of Mechanical Engineering

, Volume 13, Issue 1, pp 96–106 | Cite as

Microcellular injection molding process for producing lightweight thermoplastic polyurethane with customizable properties

  • Thomas Ellingham
  • Hrishikesh Kharbas
  • Mihai Manitiu
  • Guenter Scholz
  • Lih-Sheng Turng
Research Article
  • 81 Downloads
Part of the following topical collections:
  1. Near-net Shaping Technology

Abstract

A three-stage molding process involving microcellular injection molding with core retraction and an “out-of-mold” expansion was developed to manufacture thermoplastic polyurethane into lightweight foams of varying local densities, microstructures, and mechanical properties in the same microcellular injection molded part. Two stages of cavity expansion through sequential core retractions and a third expansion in a separate mold at an elevated temperature were carried out. The densities varied from 0.25 to 0.42 g/cm3 (77% to 62% weight reduction). The mechanical properties varied as well. Cyclic compressive strengths and hysteresis loss ratios, together with the microstructures, were characterized and reported.

Keywords

thermoplastic polyurethane microcellular injection molding cavity expansion compressive strength hysteresis loss ratio 

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Notes

Acknowledgements

The authors would like to acknowledge the support of the Kuo K. and Cindy F. Wang Professorship, the Vilas Distinguished Achievement Professorship, the Wisconsin Distinguished Graduate Fellowship, the 3M Fellowship, and the Wisconsin Institute for Discovery.

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Copyright information

© Higher Education Press and Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Thomas Ellingham
    • 1
    • 2
  • Hrishikesh Kharbas
    • 1
    • 2
  • Mihai Manitiu
    • 3
  • Guenter Scholz
    • 3
  • Lih-Sheng Turng
    • 1
    • 2
  1. 1.Department of Mechanical EngineeringUniversity of Wisconsin-MadisonMadisonUSA
  2. 2.Wisconsin Institute for DiscoveryUniversity of Wisconsin-MadisonMadisonUSA
  3. 3.BASF CorporationWyandotteUSA

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