The development of natural fibres in engineering applications requires the reliable and accurate assessment of their dimensional characteristics and mechanical properties. Fibre cross-sectional area (CSA) obtained from lateral dimensional measurements should consider the specific cross-sectional shape of natural fibres and its wide lengthwise morphometric variations. In this study, a detailed dimensional analysis was conducted on a selected panel of natural fibres with contrasted morphometric characteristics belonging to various phylogenetic plant species with dissimilar functions in planta. An automated laser scanning technique was used, and geometrical models and filtering data method were developed for calculation of reliable CSAs adapted to each plant fibre species. Results show that CSAs of palm and sisal fibre bundles can be satisfactorily assessed by a circular model with minimal data processing, whereas hemp, flax and nettle fibre bundles require specific data filtering due to partial splicing, and can be better assessed by an elliptic model.

天然纤维在工程应用中的发展需要对其尺寸特征和机械性能的可靠而准确的评估。从横向尺寸测量获得的纤维横截面积（CSA）应考虑天然纤维的特定横截面形状及其宽的纵向形态变化。在这项研究中，一个详细的三维分析的天然纤维，以及属于各个系统发育的植物物种与相异功能对比形态特性的选定的面板上进行在植物中。使用了自动激光扫描技术，并开发了几何模型和过滤数据方法来计算适用于每种植物纤维种类的可靠CSA。结果表明，可以通过圆形模型以最少的数据处理来令人满意地评估棕榈纤维和剑麻纤维束的CSA，而由于部分拼接，大麻，亚麻和荨麻纤维束需要特定的数据过滤，并且可以通过椭圆模型进行更好的评估。