CNTs monitoring sensors for resin infusion optimization

The quality of composites manufactured by means of resin infusion depends to a significant extent on expertise of operators. In order to improve both the reliability and performance of infusion, careful monitoring of the process is required. To this end, macroscopic filaments made of multi-walled carbon nanotubes (MWCNTs) were integrated into the fabrics of different materials and used to monitor the fluid front advance during vacuum-assisted resin infusion (VARI) experiments. In particular, the electrical resistance change MWCNT fiber was continuously recorded while the resin was impregnating the fabrics. Although the method does not require complex equipment, its practical implementation is far from trivial, since several external variables can significantly affect the electrical measurements. In this work, fluid pressure in the laminate, temperature, fabric compaction, and electrical contacts between the carbon nanotube (CNT) yarns and acquisition system were analyzed. It is concluded that temperature and the quality of contacts (CNT filament electrode soldering) can have a striking effect on the electrical output and must be carefully controlled. study used the hysteresis curve in the electrical resistance change appearing in different vacuum pressure cycles and fabrics to determine the position of the resin front.

Automated summary

The quality of composites manufactured by resin infusion depends on operator expertise, which can be improved through careful monitoring of the process. In this study, macroscopic filaments made of multi-walled carbon nanotubes were integrated into different fabric materials to monitor fluid front advance during vacuum-assisted resin infusion. The electrical resistance change of the filaments was continuously recorded, but temperature and quality of electrical contacts were found to significantly affect the measurements.