Natural Dyes
Susana del Val (1), Cristina Zunino(1), Laura Martínez(1), Marisa Martínez(2), Laura Reñones(2), Valeria Bartoloni(2), Sofía Frangie(2)
(1) National Institute of Industrial Technology, Textile Center. (2) National Institute of Industrial Technology, Chemistry Center
ABSTRACT The dyes were extracted, using simple and environment friendly methods, from agroindustrial waste and selected native species. The dyeing properties were evaluated regarding the yield of the process and the colorfastness of the dyed fabrics. Until today more than twenty powder colorants were obtained from vegetal materials with a responsible management of wild natural resources. All of them were used to dye woven fabric made of pure wool without the use of common mordants. Also the colorants were used for printing cotton fabrics.
Introduction Textile materials without colorants cannot be imagined and dyeing has been widely used since ancient times. Ecological and sustainable production methods are very important nowadays. In this work both, the extraction of colorants and the process of dyeing were studied taking into account these aspects. The colorants obtained in the laboratory were then obtained at a pilot plant scale (1:50). The necessary changes in methods were evaluated in the textile laboratory. It was possible to close the complete cycle: available raw material, satisfactory extraction of colorants and good performance in dyeing and printing. For textile dyeing the most promising colorants come from: peanut, onion, walnut, yerba mate and urunday, vegetal species extensively distributed in Argentina. Natural colorants were also used to print cotton with good results.
urunday
walnut
onion
yerba mate
peanut
Results and Conclusions Some results are shown in the following figures.
temperaure in C 70
Dyeing curve
60
50
40
30
20
10
0 1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86
Dyeing curve time in minutes
Dyeing with peanut colorants at different concentrations
Dyeing was carried out in a laboratory equipment (Labomat Mathis) in the following conditions: pH 4.5 (acetic acid)
R.B
temperature
gradient
time
1:10
100 ºC
3 ºC/ min
60 min
Dyeing was tested at different concentrations of colorant, being possible determine that concentrations higher than 3% don`t increase the intensity of color.
Colorfastness grey scale
Colorfastness to washing. ISO 105 C06 A1S
5 4,5
4 3,5
3 2,5
2 1,5
1 0,5
0 transf/ CO
transf/ WO
ch/co lo r
penut walnut o nion urunday yerba mate
Different natural dyes at 3% concentration on wool
According to results of dyeing it is possible to infer that an important number of the colorants obtained are suitable for protean fibers, with good or very good colourfastness to washing. It is important to emphasize that it was possible using a simple process with no mordants.
Paper ID: 147
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