新型轻木-GFRP夹芯板拉挤成型工艺及其界面性能

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

选用无碱玻璃纤维束、短切纤维毡、不饱和树脂与泡桐木芯材,制备了轻木-玻璃纤维增强塑料(GFRP)夹芯板,对其拉挤工艺进行了研究。研究表明:设定模具加热温度(凝胶区)为160℃、选取的拉挤速率为10cm/min时,可制造得到表观性能良好的泡桐木-GFRP夹芯板。通过双悬臂梁(DCB)试验,在芯材表面开槽和不开槽2种情况下,研究了泡桐木与GFRP面层之间的界面黏结性能,并与真空导入工艺制作的夹芯板的界面黏结性能进行了对比。结果表明:拉挤工艺生产的泡桐木-GFRP夹芯板的界面黏结性能已达到甚至优于真空导入工艺生产的。芯材表面开槽可以有效提高试件的界面能量释放率,且对真空导入工艺制作的试件效果更为明显。在拉挤工艺中,树脂难以有效填充齿槽形成"树脂钉",故不能明显提高界面黏结力。在对界面性能要求不严格时,拉挤工艺中芯材表面可不开槽,以减少生产工序、降低生产难度。

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 10cm/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.