The results indicate that the difference of fracture toughness between MD and CD increases with a decrease in jet_wire speed ratio,and the main reason is stronger fibre orientation.

• 试验结果表明：减小浆网速比，增强了纤维定向作用，裂缝纵向分布增加，导致纸张中纵横向断裂韧性差异增加。