Quantitative analysis of pore shape in spunbonded nonwovens

To study the characteristics of the pore shape in spunbonded nonwovens,five kinds of spunbonded polypropylene nonwovens were produced using different mesh belt frequency. The pore shape was characterized by 8 indexes such as breadth / length ratio. These indexes were measured by employing digital image processing technology. The reducing dimension calculation was applied to the above indexes using principal component analysis. Thus two principal components which reflect the pore flat degree and boundary roughness were extracted,respectively. Therefore it not only eliminates the interdependence among original indexes,but also simplifies the study. The influence of the mesh belt frequency on the pore shape was analyzed and the results show that with the increasing of the mesh belt frequency,the pore shape tend to become flatter,and the boundary roughness value first declines and then rises. The research results can provide a certain reference to understand the intrinsic mechanism of the influence of the pore shape on the filtration performance and the mechanical property of nonwovens.