Scientists from Iowa State University (ISU) recently unveiled a natural alternative to synthetic clothing pigment. This natural alternative is sourced from brewed coffee grounds.

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The research team, spearheaded by ISU Assistant Professor Chunhui Xiang and graduate student Changhyun “Lyon” Nam, found a possible alternative via repurposed coffee grounds. Rather than adding to landfill density and single-use waste, brewed coffee grounds can instead be transformed into another high-value resource.

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Brewed coffee grounds are feasible because 100 million Americans drink coffee daily, meaning there is an adequate supply of coffee grounds that can be upcycled and diverted away from landfills. Shades of brown can be extracted from the coffee grounds, then bound to various textiles and fabrics.

Of course, there remain the quandaries of fading and of replicating consistent hues. While the use of pigment fixative helps to bind the color to the fabric and reduce fading, producing consistent hues that can match a template proves to be more complex. More research is required before repurposed coffee grounds can be ready for mass-production of pigments. 

“One disadvantage is that it’s hard to measure the quantity needed to get the same color,” Xiang explained. “There may be a difference in the type of beans, or maybe the coffee was brewed twice. Creating an exact match is a challenge, especially for manufacturers.”

However, Xiang asserted that hue consistency can be overcome by changing consumer attitudes. If consumers are able to reframe their interests so that they accept the uniqueness of colors rather than demand their consistency, then repurposed coffee grounds, as a sustainable source, can be a worthwhile commercial venture.

Historically, textile hues were originally sourced from plants and minerals.  But industrialization forced the textile sector to turn to synthetics, because laboratories could produce them at cheaper cost. Over time, these synthetics have become less and less environmentally friendly. Because the textile industry utilizes upward of 2 million tons of chemicals for its synthetic pigments, there has been a growing movement in today’s society to find more sustainable sources, such as repurposed coffee grounds.

+ Taylor and Francis Online


Image via Couleur