Analysis and Simulation of Nonwoven Irregularity and Nonhomogeneity

Abstract

This paper presents a study of nonwoven fabric irregularity. The method of two- dimensional random fields has been used to investigate longitudinal, transverse, and area irregularities, and micro- and macro-scale irregularities are determined. The effects of inherent random irregularity and transverse nonhomogeneity are described, and a method for separating these effects is suggested. Computer-aided simulation is used to verify and illustrate algorithms for the nonhomogeneous and irregularity analysis as applied to nonwovens. The influence of an average cross-profile of random field irreg ularities on the coefficient of variation in the transverse direction is determined. A macro-scale irregularity analysis of chemically bonded nonwoven fabrics yields esti mates of the longitudinal, transverse, and area irregularities, the value of the "degree of influence," estimates of two-dimensional correlation functions, and a set of corre lation functions in the longitudinal direction.

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