Natural dyes from agricultural waste in dust form. Photo: INTI.
Although natural dyes for textiles are widely spread in the green world (with a production house in Chicago and many DIY tutorials around), the Argentine National Institute for Industrial Technology (INTI) is taking an interesting alternative approach: they're experimenting with the extraction of pigments from agricultural waste and its conservation in dust form. They've already tested 20 different materials, and are very excited about peanut shells. Learn more inside.According to the INTI website, the experiments are being carried away by the Chemical Department of the Institute, which observed the global trend of going back to natural dyes and wanted to make pigments more widely available, also reusing existing materials from the agriculture and agroindustrial sector.
Natural dyes are currently extracted by boiling vegetable products in water, but the institute thinks that extracting and conserving pigments in dust form can strengthen their availability through seasons and adverse climate conditions, while also having a better performance with textiles. Of course, the recycling of waste is a plus.
They've already extracted colors from 20 different waste types, including rests of eucalyptus, aguaribay trees, sunflower seed shells, parsley, olive, laurel, and lemon trees, among others. But the ones that worked the best have been peanut shells, nuts pericarps, guayacan trees, carob tree liquids, romerillo, ash tree, yerba mate, onion, mistol, colliguay and palo pinche.
A sample of textiles dyed with different concentrations of peanut shell pigment. Photo: INTI.
Unlike textiles dyed with the boiling water method, they've found that those colored with the extracted dust are more resistant to washing and use. However, they are very sensitive to light, like all natural colorants.
Particularly, they're excited about peanut shell pigments, which they say have similar characteristics to synthetic dyes and which are widely available since Argentina is one of the world's top exporters of peanut (who knew).
In the future, they will also evaluate the application of these colorants in other areas besides fashion, like food, cosmetics, paint, paper and rubber.
For more information on the studies, contact the Institute through the people in charge, whose e-mails are listed at the organism website.