Comparison of steady-state and transient thermal conductivity testing methods using different industrial rubber compounds

Roman Christopher Kerschbaumer, Sebastian Stieger, Mario Gschwandl, Thomas Hutterer, Michael Fasching, Bernhard Lechner, Lisa Meinhart, Julia Hildenbrandt, Bernd Schrittesser, Peter Filipp Fuchs, Gerald Berger-Weber, Walter Friesenbichler

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    12 Citations (Scopus)


    Reliable material data, especially of the thermal conductivity as a function of temperature, are crucial for the
    virtual optimization of the rubber injection molding process. Due to the low thermal conductivity of rubber
    compounds, typically in the range from 0.15 to 0.4 W m 1K 1, and the fact that the molding of the rubber part
    takes place in a heated mold via an energy-based crosslinking reaction, the total cycle time is in the range of
    minutes. Consequently, there is a vast potential for optimization of this lengthy production cycle. To determine
    the thermal conductivity of seven different rubber compounds, a stationary (Guarded Heat Flow Meter (GHF)),
    and three transient methods (Plane-Source (TPS), Line-Source (TLS), and Laser Flash Analysis (LFA)) were
    employed. Ancillary, the anisotropic TPS- and the LFA-method require the material parameters specific heat
    capacity as well as density. The TPS method also offers the possibility to perform an isotropic and an anisotropic
    measurement of the thermal conductivity. In general, filled rubber systems do not exhibit an isotropic material
    behavior. Due to filler orientation or diffusion of volatile substances to the surface, the values of the thermal
    conductivity obtained from TPS-method differ significantly from those of GHF or LFA. The TLS-measured
    thermal conductivity coincide with the GHF results; however, TLS is limited to rubber compounds containing
    no cross-linking system, and it is sensitive to emitted volatile substances. To conclude, both the GHF- and the
    LFA-method provide comparable results for all seven tested rubber compounds.
    Original languageEnglish
    Article number106121
    Pages (from-to)1-8
    Number of pages8
    JournalPolymer Testing
    Issue numberDecember
    Publication statusE-pub ahead of print - 26 Sept 2019

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