Whiteness assessment of FWA-treated nylon fabrics - A different approach

Abstract

<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">The spectral reflectance data of 110 nylon fabric samples treated with five different fluorescent whitening agents (FWAs) at twenty-two different levels (0.1-3%) were recorded on DATACOLOR instrument. The whiteness of the samples, expressed by single numeral using Ganz formula, varied from 150 to 250 Ciba-Geigy units. A whiteness formula containing CIELAB colour coordinates is proposed. The proposed formula has been tested for five different FWAs and four different sources having varied spectral power distribution in UV region. The difference in whiteness assessed by Ganz and proposed formulae ranges from 15 to 25 units. These variations are of the same magnitude as minimum perceptible whiteness by human eye. The application of proposed formula does not require any calibration or complicated computations as needed for Ganz formula but at the same time gives reasonably good results.</span>