• Tobias Standau
  • Volker AltstädtEmail author


This chapter deals with polypropylene foams and consist out of 3 parts. Firstly—for a better understanding—the basics of foaming are described. This includes the fundamental physical processes of diffusion, nucleation and cell growth. Furthermore, material properties which are relevant for foaming are explained and typical blowing agents (physical and chemical) are introduced. Secondly, the foaming processes for polypropylene are summarized, beginning with the so-called batch foaming which is mostly relevant for scientific research. More industrial relevant processes for foaming PP are foam extrusion, foam injection molding (FIM) and bead foaming. With FIM light-weight parts with good mechanical properties can be produced. This can be achieved with physical and chemical blowing agents and with different methods. Bead foams possess a very low density and can be directly brought into relative complex shapes. Therefore, expanded Polypropylene (EPP) is maybe the most important PP foam at all. Both methods for bead foam production (discontinuous with autoclave and continuous with extrusion process) are described as well as the fusion processe (steam chest molding). The last part of this chapter is designated to the many additives that are used in PP foams (i.e. talc, clay etc.) and their influence on properties like expansion behavior and foam morphology.



For their contribution to this chapter the following people are acknowledged (in alphabetic order): Merve Aksit, Christian Bethke, Dominic Dörr, Katharina Krause, Michaela Mörl, Daniel Raps, Nick Weingart and Chunjing Zhao.


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Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Department of Polymer EngineeringUniversity of BayreuthBayreuthGermany
  2. 2.Neue Materialien Bayreuth GmbHBayreuthGermany

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