Analysis of Colorfastness in Metallic Prints Using Absorption Spectroscopy

Abstract

Color is essential for the fashion and art of fabrics, with its retention being a quality measure of great significance for the brand and user. The colorfastness of some metallic fabrics has been established using absorption spectroscopy, by determining the quality and quantity of dye that bled after undergoing wash laundry processes. Two metallic fabrics (X and Y) and washing detergents (liquid and powdered) were used. The fabrics were washed using GyroWash machine set for normal (40°C) and hot (60°C) wash for durations of 60 min and 90 min. There was a repeat for a second wash. The wastewater after each wash (sample) was collected, and the absorption spectra were recorded using a double-beam spectrophotometer. The quality of dyes drained was determined using Peakfit analysis to deconvolute the absorption spectrum to reveal the presence of multiple individual wavelengths, and quantified using their relative intensity values. The identified peaks were between 200 nm and 370 nm, which lie within the UV–Vis absorption band of synthetic dyes referred to as azo dyes. The liquid soap bled more dye under the same washing conditions, with fabric Y demonstrating an inferior ability to retain its dye compared to fabric X. A higher amount of dye was drained during the hot wash, with the amount of dye that bled from both fabrics reducing after the first wash. Euclidean similarity was performed using principal component analysis to identify the spectra close to the detergent solution (reference spectrum) in Euclidean distance sense. Points from the wastewater spectra similar to the reference had shorter absolute distances, indicating less bleeding, while more dissimilar points registered longer distance, indicating more bleeding. This absorption spectroscopy technique is scientific and objective compared to the conventional subjective gray scale method. It will help textile manufacturers develop standardized testing protocols to assess the colorfastness of metallic printed fabrics, ensuring that products meet quality standards before they reach the market.