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.