低密度芳纶纸蜂窝制备及力学性能

Preparation and Mechanical Properties of Low Density Aramid Paper Honeycomb

采用国产X612N-1.5mil规格的芳纶纸制造了低密度(29,22.4kg/m^3)蜂窝芯材,研究了国产X612N型芳纶纸的定量与白蜂窝(未浸渍)密度的关系,蜂窝压缩强度与酚醛树脂增量的关系,浸胶次数对蜂窝密度均匀性及压缩强度的影响,且测试低密度蜂窝在三种条件下(25,135,70℃及湿度70%)的力学性能。结果表明:白蜂窝密度与芳纶纸定量成正比关系,比列系数为1.14(孔格边长:1.83mm)和0.68(孔格边长:2.75mm);压缩强度与酚醛树脂增量成正比关系,比列系数为0.082。浸胶2次有利于控制密度的均匀性和压缩强度,浸胶1次的蜂窝密度离散系数(CV)为7%,浸胶2次的蜂窝密度CV为2.4%,压缩强度可提高38.3%~26.5%。经过湿热老化环境处理30天后,蜂窝的非稳态压缩强度、L及W向剪切强度和模量降低幅度小于10%,高温(135℃)条件下,两种规格芳纶纸蜂窝的非稳态压缩强度的降低较大,降低幅度为21%~28%,L和W向剪切强度和弹性模量降低幅度为4%~20%。

The domestic X612N–1.5 mil aramid paper was used to prepare the low density(29 kg/m^3,22.4 kg/m^3)honeycomb core materials.The relationship between the basis weight of domestic X612N aramid paper and the density of white honeycomb(un-dipped),the relationship between honeycomb compression strength and phenolic resin increment,and the effect of dipping times on core density uniformity and compressive strength were studied and low density honeycomb’s mechanical properties under three conditions(25℃,135℃,70℃and 70%)were tested.The results show that the density of white honeycomb is proportional to the basis weight of aramid paper,the ratio coefficient is 1.14(cell side length:1.83 mm)and 0.68(cell side length:2.75 mm).The compressive strength is proportional to the increment of phenolic resin,the ratio coefficient is 0.082.Dipping two times could control the uniformity of density.The coefficient of variation(CV)of core dipping one time is 7%,the CV of core the dipping twotimes is 2.4%,and the compressive strength can be increased from 38.3%to 26.5%.After 30 days of treatment in a damp heat aging environment,the unsteady compressive strength,L and W shear strength and modulus of the honeycomb decreased by less than 10%.Under high temperature(135℃),the aramid paper honeycombs of two specifications were unstable.The compression strength of the state is greatly reduced,the reduction range is 21%to 28%,and the shear strength and modulus of the L and W are reduced by 4%to 20%.