Determination of Pore Size Distribution in Fibrous Webs and its Impact on Absorbency, 1996 Nonwovens Conference Proceedings

L. F. Fryer & B.S. Gupta

North Carolina State University

Porous materials are used in a wide variety of products, including filters, barrier fabrics, dressings, and absorbent goods. The performance properties of these structures depend upon. among other characteristics, the pore size distribution and its stability during use. Although papers exist in the literature on characterization of pore structures of fabrics, details are often missing which make reproduction of the method most difficult. Numerous problems are encountered which must be overcome. Described in this paper are the details of a method that can be used to determine (1) the distribution of pore sizes in a material, (2) the changes in pore properties with cycling and (3) the impact of pore structure on absorbency. The device used can be interfaced with a computer and programmed to function automatically. Experimental work performed included characterization of pore structures in carded webs, needled and unneedled, of three cotton fibers, differing in micronaire values and mechanical properties, and a modified rayon fiber of multilobal cross-section. Preliminary results obtained show that the pore characteristics of a web are influenced by both the properties of the fiber and the nature of the processing used. Examination of the absorption/desorption cycling curves provided information about performance of absorbent products not obtainable from the simple deman-wettability tests, often used in characterizing the behavior of absorbent products.