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How a tea stain turned into a fashion opportunity


Waste from our Ceytea factory in Sri Lanka is being transformed into a suite of natural fabric dyes that are providing the fashion industry with greener alternatives

T-shirts in a field

Agarapathana, in the heart of the hills of Sri Lanka, is the base for Ceytea, Unilever’s instant tea factory. The site’s 153-strong workforce produces 2,500 metric tons of ready-to-drink tea powder for our Lipton iced tea business each year.

Every day the factory generated five tons of waste tea sludge. Ceytea’s factory manager, Anusha Kotalawala and her team were working to find ways to reduce this and its environmental impact.

Their solution was originally a problem on their ‘to-do’ lists. “The waste tea sludge was staining our factory uniforms,” says Anusha.

“The idea that this could be an opportunity came to light when we were approached by Professor Vinitha Thadhani, a senior research scientist and inventor from SLINTECH, Sri Lanka’s leading Nano-Tech Institute,” explains Anusha. “She was undertaking research in natural dyes and we literally came up in a Google search.

“We started to think, could the tea stains on our uniforms actually be an opportunity to develop a fabric dye from our own tea?” she says.

Testing the idea

“We knew that to create a natural plant dye, the supply chain, cost and, most importantly, reproducibility, had to be developed and tested,” Anusha explains. “Not all plant dyes give a dye that holds fast to light and washing.” That meant SLINTECH and Ceytea also required a partner from the textile industry – and this was garment-dyeing and wash firm Dynawash.

The three enterprises partnered up to move the idea forward. “We supplied the base ingredient, SLINTEC carried out the R&D, and Dynawash worked on the fabric dyeing and commercialisation, all with the help of funding from the Export Development Board of Sri Lanka,” says Anusha.

It took nearly three years of research and one year of research and development for SLINTEC to come up with a process that created an effective dye that met industry standards. And that’s pretty fast in R&D terms.

What helped, says SLINTEC’s senior research scientist, Professor Thadhani, was “the uniformity of the raw material, and that it came in a ready-to-use soluble powder or liquid concentrate just like synthetic dyes”.

It’s amazing how far we have come, the tea sludge used to get all over our clothes. Today, all of our uniforms are created from fabric that has been dyed with natural dye made from our own tea. Ceytea factory manager Anusha Kotalawala

From waste to wardrobe

Today, as well as producing instant tea powder, the Ceytea factory manufactures the base ingredient for a suite of natural fabric dyes. The brand name for the dyes is T-Hues, a lovely reference to where they came from.

The process sees the tea waste segregated, filtered and spray-dried to create the base for tea dye in powder form. This can then be transformed into a range of 15 natural colours to suit textile manufacturers’ needs.

As a sector the fashion industry could account for more than 8% of global climate impacts and textile production plays a big part in that.

“There is a big push from global brands to make the apparel supply chain sustainable under the ZDHC initiative: a collaboration of major fashion brands, value chain affiliates and associations driving global implementation of safer chemical management practices,” acknowledges Dynawash’s CEO, Shahid Sangani.

Colouring a garment using a non-toxic, biodegradable and eco-friendly natural dye such as T-Hues cuts water consumption and dyeing time, and could reduce the carbon footprint from dyeing a cotton crew neck t-shirt by three-quarters and a nylon T-shirt by one-third.

“It’s amazing how far we have come,” adds Anusha. “The tea sludge used to get all over our clothes. Today, all of our uniforms are created from fabric that has been dyed with natural dye made from our own tea.”

And workwear is just the start. The T-hues team are in the process of presenting ranges of naturally dyed scarves, shawls, hoodies and t-shirts to big retailers, including the UK’s Marks & Spencer.

“We’re very proud to have developed a sustainable natural dye from our tea waste,” says Anusha. “It not only has great social and economic benefits for Sri Lanka but also it helps us take another step forward in making sustainable living commonplace.”

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