Original use of electrical conductivity for void detection due to injection conditions of composite materials

The void defects present in composite parts are due to air entrapped during the injection process. We propose to use electrical conductivity measureme nts of the liquid to detect these defects. The saturation rate of the resin is measured as a function of time. Thanks to several sensors, placed along the mould, we are able to plot the resin front profile evolution versus th e position. This method is a step forward in our knowledge of the parameter range for which no void is observed at the end of the injection. (C) 2001 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.