【作者】 杨旭红；

【导师】 李栋高；

【作者基本信息】 苏州大学 ， 纺织工程， 2003， 博士

【摘要】 非织造材料是基于既古老又具有崭新加工工艺的非织造技术的一种纤维材料，它最大的优点是可以按最终产品的使用性能，科学地设计加工技术、工艺路线，最充分有效地利用资源，生产出满足最终用途要求的产品。它在工业、农业、城市建设、医药卫生、衣用家用纺织品等领域都具有越来越广泛的用途，可以用作各种过滤材料、气体或微粒的吸附材料、土工材料、隔热隔音材料、电器绝缘材料、农产品的培养基等，同时也可作为一种基质材料，用于和其他物体构成复合材料。而无论是作为单一材料还是复合材料，其功能都与纤维集合体的多孔结构密切相关，如孔隙的形状、数量、大小分布等。而孔隙的结构又与纤维的粗细、数量、卷曲程度、取向程度以及纤维集合体的成形方式等有关，因此若能找到可直观方便地描述这种非织造纤维材料的结构参数，进而找出这些结构参数与制造方法、产品性能之间的有机联系，则无论对其生产还是用途都具有十分重要的理论指导意义。但由于这类材料结构的复杂性和随机性，长期以来，运用传统几何学一直未能有一个统一有效的刻划方法来表征其结构特征。随着非织造纤维材料的应用价值进一步被认识和应用领域的进一步扩大，其结构特征的定量表述现已成为一个急待解决的问题。 分形几何为研究非规则几何对象提供了一种新的思想和有力的工具。因此，本文首先借助分形理论并结合计算机图象分析技术对实际纤维网进行了结构研究，发现非织造纤维网的孔隙大小分布具有明显的分形特征，并计算出了孔隙分形维数，用以表达孔隙大小分布的规律。同时结合反映孔隙形状的紧密度和粗糙度等参数，以及反映纤维状态的纤维取向分布函数来比较全面地表征非织造材料不规则性的形态结构。 然后在对常用纤维卷曲形态的分形特征进行分析的基础上，通过Visual Basic语言编程，利用随机分形曲线模拟了纤维的卷曲形态，进而模拟了由卷曲纤维构造成的各种类型的非织造纤维网。 在此基础上，利用编制好的参数化程序，通过改变纤维的直径、卷曲程度、取向分布、纤维网定量等参数，产生了大量的模拟纤维网图象，并提取了其结构 非织造材料(纤维网)形态结构的表征与分形模拟提要特征参数，从而研究了生产加工中纤维直径、卷曲、纤维取向分布、纤维网定量等对非织造纤维网孔隙结构的影响。 通过对实际非织造纤维网的直观图象分析研究，本文发现其孔隙分形维数与纤维网的透通性能之间存在一定的关系:而利用模拟纤维网进行研究的结果表明，纤维直径、卷曲、纤维取向分布、纤维网定量等对纤维网的孔隙分形维数有明显的影响，同时后三者对孔隙形状也有较大影响。由此说明，对非织造纤维网的形态结构进行表征和模拟，可以为在更深层次上揭示非织造纤维网的生产、结构与使用性能之间的关系提供理论基础。更多还原

【Abstract】 Nonwovens are fiber materials which are based on nonwoven technologies. Nonwoven technology embodies both quite old and the very new processing techniques. From a fairly modest beginning with only a limited variety of raw materials, processes, and end uses, the nonwoven industry has reached a state of enormous diversity. Their most advantages are that the processing technologies and forming methods for the products can be designed scientifically according to their end-use. So that the resources can be used most adequately and the satisfactory products be obtained. The applications of nonwovens in industry, agriculture, civil construction, sanitary, home-use and so on, are wider and wider. They can be used as various kinds of filters, adsorbents, geotextiles, insulation materials of heat, sound and electricity, culture medium of farm produces, etc.. Meanwhile, they also can be used as fundus for composite materials. Whether they are used as single or composite materials, their properties are related to their porosity structures, such as pore shape, pore size, pore quantity and pore size distribution and so on. And the porosity structures are related to fiber diameter, fiber crimp, fiber orientation, fiber quantity and the forming method of the fiber aggregations. Therefore, it is important for both manufactory and end-use to obtain the parameters which can be used to express the structure of nonwovens conveniently, and furthermore to find out the relationships between structures parameters and produce methods and properties of products. But for the complexity and randomness of nonwovens structures, it is difficult to express their structures effectively using classical geometry. With the enlargement of their applications, it is urgent to find a way to express their structures quantitatively. Fractal geometry give us a new idea and a powerful tools to study on irregularity ofgeometric objects. Therefore, we studied on the morphologic structures of real nonwovens using fractal geometry combined with computer image processing technology first. The result shows that the pore size distribution in nonwovens is fractal, and the rule of pore size distribution can be expressed by fractal dimension. Fractal dimension, combined with compactness and roughness which are related to pore shape, and fiber orientation function, is found to be capable of express the irregular morphologic structures of nonwovens in the round.Then, on the basis of studying on fractal character of crimped morphology of routine fibers, we simulated the crimped fibers using fractal curve through programming with Visual Basic Language. Furthermore, we simulated various kinds of nonwovens made up of crimped fibers.Finally, a large series of simulated nonwovens were generated through changing the fiber diameter, fiber crimp, fiber orientation and fiber quantity in the program, so as to study the effect of those fiber parameters mentioned above on fractal dimension of pore size distribution and pore shape.The study on real nonwovens indicates that the fractal dimension of pore size distribution is related to nonwovens permeability; and the results from simulated nonwovens show that fiber diameter, fiber crimp, fiber orientation and web density influence the fractal dimension of pore size distribution prominently, and the latter three also influence the pore shape obviously. Accordingly, we know that to express and simulate the morphologic structures of nonwovens will provide the theoretics foundation for revealing the relationships between manufacture, structure and properties of nonwovens in a deep level.更多还原