Pultrusion process and interface performance of new light wood GFRP sandwich panels

Alkali-free glass fiber bundle, chopped fiber, unsaturated resin and paulownia wood were selected to prepare light wood-glass fiber reinforced plastic (GFRP) sandwich panels. And the pultrusion process was investigated. Research shows paulownia wood-GFRP sandwich panels with good apparent performance can be prepared by suitable temperature of mould heating area (gel area) and pultrusion rate which are 160 ℃ and 10 cm/min, respectively. Compared with panels maded by vacuum infusion process, as for the sandwich panels with or without groove on surface of wood core, the interface bonding property between paulownia wood and GFRP panels was investigated by double cantilever beam (DCB) test. The results show that pultruded paulownia wood-GFRP sandwich panels are up to ones of vacumm process in interfacial bonding properties. The measure of groove on surface of core can effectively increase the energy release rate. And its effect is more obvious for panels made by vacumm infusion process. The resin is difficult to fill groove adequately to form resin nails in pultrusion process, and the groove can not improve the interfacial adhesion efficiently. So ungrooved core can reduce the production process and production difficulty when the interface performance requirements are not strict.