Microwave Curing of Glass-Epoxy Composites Using Silica Based Moulds

Abstract

Abstract

For polymer composite product manufacture, curing of the fibre reinforced polymers (FRP) is a critical step in achieving desired mechanical properties. The conventional cure processes involve thermal curing in hot air ovens and autoclaves where the cure process is time and energy intensive. In this context, microwave curing is one of the most promising processing methods since it results in  substantially reducing cure cycle time, energy requirements and operational costs due to its volumetric mode of heating. In the present work, 2 mm thick glass-epoxy composite laminates have been cured using a conveyorised microwave system. The epoxy matrix is LY5052/ HY5052 resin system. Since the use of metal moulds inside a microwave system could lead to arcing, hot spots and damage to microwave sources, two different, ceramic moulds based on fused silica were fabricated in-house and employed for microwave curing. One was a microwave transparent fused silica mould and the other a microwave absorbing dielectric mould.  The temperature uniformity of the moulds was assessed using an IR pyrometer and IR camera.  Cure completion of microwave cured laminates was ascertained by Tg measurement and mechanical property determination, which were compared with thermally cured counterparts in order to evaluate the efficacy of the moulds for rapid, uniform and energy-efficient microwave processing.

Keywords:  Microwave curing, glass-epoxy, mould, silica, dielectric

Cite this Article

Microwave Curing of Glass-Epoxy Composites Using Silica Based Moulds. Sandhya Rao, Chiranjeevi M C. Journal of Polymer & Composites. 2015, 3(2): 52–57p.