加捻对芳香族聚酰胺纤维拉伸性能的影响

本文对加捻芳香族聚酰胺纤维的拉伸性能进行了①定长加捻后拉伸;②定张力加捻后拉伸和③定长加捻后再退捻随后拉伸等三方面的测试.结果表明,芳香族聚酰胺纤维的强度及断裂伸长随捻度的增加而下降.对纤维断裂端进行了扫描电镜观察.加捻芳香族聚酰胺纤维断裂形态照片显示了纤维沿轴向分裂为微纤的现象,证明了微纤间横向联系的薄弱.加捻作用更削弱了这种联系,从而使纤维强度下降.本文对芳纶纤维在加工过程中应严格控制加捻提供了依据.

THE TENSILE PROPERTIES OF TWISTED ARAMID FIBRES

The tensile properties of twisted aramid fibres have been measured under three experimental procedures, (1) twist at constant length, followed by extension, (2)twist at constant tension,followed by extension, (3)twisting and untwisting at constant length prior to extension. The tests show that the strength and breaking extension of aramid fibres decrease with twisting. The morphology of the broken ends of the fibres were examined by SEM. The SEM view of a twisted Kevlar Filament broken shows the very pronounced splitting. It indicates that highly oriented aramid fibres have high axial strength but low transverse link, so that it might be expected that the presence of fibre twist would have a major influence on the tensile properties of these fibres. This paper suggests that fibre twist should be well controlled during its processing.