THE STRENGTH OF CHEMICALLY BONDED NONWOVEN FABRICS AS A FUNCTION OF THE IONIC CHARGES OF BINDERS AND FIBERS

This study compared the tensile strength of chemically bonded nonwoven fabrics as a function of ionic charges of fibers and fiber finishes and of binders and binder emulsifiers. The binders were applied at normal (20%) and low (5%) concentrations; the low binder level was used to avoid possible masking of ionic interactions. In all, 70 different nonwoven fabrics were prepared for tensile measurements.;These findings are consistent with the knowledge that ionic charges buried in the polymer backbone such as in the fiber and in the binder, would be inaccessible because of distance and lack of mobility. Conversely, these findings are also consistent with ionic interactions found with the fiber finishes and the binder emulsifiers; these are small molecules with mobility.;The means and standard deviations of the tensile data were examined by analysis of variance. The tensiles varied significantly (.05) among the nonwoven fabrics. Multiple comparisons using Scheffe's tests showed which binders differed significantly (.05) from each other. On the basis of rank ordering the results of Scheffe's tests, it appeared that greater tensile strength resulted from ionic interaction between the binders and fiber finishes as well as between the binder emulsifiers and fiber finishes. There was no indication of ionic interaction between the binder and fiber or binder emulsifier and fiber.