Colour gamut of natural dyes on cotton yarns

Abstract

Cotton fibres were dyed using various natural dyes alone and in combination to yield six basic shades: blue, yellow, red, black, green and fawn. These dyed fibres were then blended in various proportions along with undyed cotton fibres and spun on a rotor-spinning machine to produce 204 coloured yarns. The fastness properties of the six basic shades were determined. The L*a*b* and L*C*h values of the yarns having 50% dyed fibre and 50% undyed cotton fibre was also determined. The values were plotted to obtain the colour gamut of natural dyes on cotton yarns. Experimental MaterialsPrescoured J-34 cotton fibre was used without any further treatment. The natural dye powders used for the study were obtained from Alps Industries Limited and were used without any further purification. The dyes used were Rhine M (a red dye extracted from the secretion of insect Kerria lacca), Nile (based on natural indigo, from Indigofera tinctoria) and four tannin-based colours: Kango (from Terminalia chebula), Amber M (from Quercus infectoria), Pacific (from Punica granatum) and Thar (from Acacia Catechu).The reactive Procion dyes used were Golden Yellow HE-R, Navy Blue N5RLI, Red HE-7B, Green HE-4BD and Turquoise Blue HE-5G.The light fastness of the yarns was tested on an ATLAS Suntest CPS+ machine having an air-cooled Xenon arc lamp by the AATCC Test Method 16-1993. Wash fastness of the samples was tested according to ISO 2 specifications. Rub fastness of the samples was tested as per the Indian standard based on ISO 105/X:1984. The L*a*b* values and L*C*h values of the samples were measured on the GretagMacbeth Colour-Eye 7000A Spectrophotometer utilising Optiview ProPalette software. Dyeing proceduresDyeings were carried out on the cotton fibres in a H-Krantz-Aachen Maschinen 3 kg sample dyeing machine. The liquor to goods ratio was kept at 20:1. The dyeing procedure (including pretreatments) varied in accordance with the dye used and the colour required. Dyeing to obtain a blue shadeThe fibres were first pretreated with 1% Amber M and 1% Kango and 0.08% ferrous sulphate for 1 h at 90 °C. A 3% shade of Nile was then dyed on the pretreated fibres. 226

Reuse of ash‐tree (Fraxinus excelsior L.) bark as natural dyes for textile dyeing: process conditions and process stability

“…Relevant experimental conditions and average CIELAB values are given in Table 2 (dyeings 7 and 8). Only very small differences in CIELAB coordinates were observed between the dyeing obtained with the first extract (7) and the dyeing with use of the second extract (8). Only a part of the colour-forming material was extracted in the first boiling procedure and a higher amount of colorant could be obtained with use of optimised extraction procedures.…”

“…For technical application of natural dyes, a number of requirements have to be fulfilled. Most problems are derived from technical demands, for example: -adaptation of traditional dyeing processes on modern equipment [8,9]; -supply of dyehouses with the required amount of plant material [10][11][12]; -selection of plant material and processes that yield products with acceptable fastness properties [13][14][15][16][17]; and -standardisation of plant material [13,18].…”

The use of cochineal and Monascus purpureus as dyes for cotton fabric

“…A mordant, usually a metallic salt, can itself be fixed on the fibre and also combines with the dyestuff. A link is formed by the mordant between the fibre and the dye, allowing the fixation of certain dyes that have little to no affinity for cotton fibre .…”

Extraction of natural dyes for textile dyeing from coloured plant wastes released from the food and beverage industry

“…Residues from vegetable and tea processing in the food (13,14) and beverage (15) industry can be extracted to obtain beige (15a, 15c), orange (12c), yellow-brown (12a, 13a, 14a, 14c, 15b) and olive (12b, 13b, 14b) shades with good fastness (Table 5).…”

“…10 The extraction and quantification of anthocyanin dyes and phenolic components has also been studied in detail. 11,12 Gulrajani et al 13 studied the application of tannin-based natural dyes for dyeing of cotton. A number of yellow/red dyes can be extracted from intensively coloured residues from the food and beverage industry, e.g.…”