Food-waste dyes bring colour to mycelium leather by Sages and Osmose
CategoriesSustainable News

Food-waste dyes bring colour to mycelium leather by Sages and Osmose

Two British materials companies, Sages and Osmose, have collaborated to dye sheets of mycelium with natural food waste, mimicking the appearance of tanned leather and suggesting a colourful future for the biomaterial.

Osmose is a company making a leather alternative from mycelium – the fibrous underground root network of mushrooms – while Sages makes natural dyes from food waste such as avocado pits, blueberries, red cabbages and onion skins, which are normally applied to textiles.

The two believe they’ve achieved a world first with their collaboration, combining two emerging areas of sustainable material development to colour mycelium without resorting to petroleum-based synthetic dyes, thereby keeping the product non-toxic and able to biodegrade safely in soil.

A small square piece of leather-like material, in a mottled hue of caramel brown A small square piece of leather-like material, in a mottled hue of caramel brown
Sages and Osmose have developed a natural dying process for mycelium leather

“There are lots of different types of vegan leather alternatives to traditional leather but the majority of them use either synthetic colourations or they use plasticisers, so they’re non-biodegradable,” said Sages CEO Emily Taylor.

“We wanted to explore an option where we could have a fully biodegradable leather that has also been coloured in a biodegradable and sustainable manner,” she continued.

Companies that prioritise biodegradability have offered mycelium in its natural shades of white and brown or black, which Osmose CEO Aurelie Fontan says is much easier to achieve naturally.

“I think the challenge for mycelium leather was that the offering just wasn’t there in terms of aesthetic,” she said. “When you’re presenting for brands and you’re like ‘we can only do brown’, it’s a little bit boring for them.”

Photo of swatches of mycelium dyed in different shades of tan, pale violet and mulberryPhoto of swatches of mycelium dyed in different shades of tan, pale violet and mulberry
The companies experimented with different food wastes in the dyeing process

“The colour sector is somewhere where you can develop your USP, essentially, which is why working with Sages is so interesting,” Fontan added.

Osmose and Sages have created tan-coloured mycelium sheets using avocado waste, which Sages sources from an importer and guacamole factory in Milton Keynes, where tens of tonnes of leftover pits and skins are produced each week.

It was a new area for both companies, as the food waste dye takes differently to mycelium leather than it does to the usually cellulose-based textiles that Sages has worked with.

The duo collaborated with materials science researchers at the UK’s Cranfield University on the project, for which the researchers focused on how to transfer and fix the dye to the material using “green chemistry” – an area of chemistry that aims to cut out hazardous substances.

In this case, the researchers sought to replace the formic acid and fluorinated acids that are often used in tanning to dissolve the polymers of the leather so it can be infused with dye. Instead, the team developed a method, which they say is significantly less toxic.

After working with Cranfield University, Sages and Osmose expanded the experiment and trialled other waste streams such as blueberries and onion skins to see what colours they could get, producing mycelium swatches in shades of violet and bordeaux.

Taylor and Fontan say they are trying to develop a process for mycelium that is akin to leather tanning, where both colour and durability properties are added in one or two steps. Their equivalent, they say, would be to dye and waterproof the material at the same time.

Close-up of vegan mycelium sheet showing its similarity to the texture of tanned leatherClose-up of vegan mycelium sheet showing its similarity to the texture of tanned leather
The tan colour was created by using waste avocado pits and skins

Osmose’s focus now is on developing a waterproof coating for their mycelium that, like the dye, is bio-based, non-toxic and able to biodegrade safely in soil. This is notoriously a challenge for plant-based leather alternatives, which almost always rely on a protective synthetic coating.

“It’s really hard to design a solution that fits all materials, which is basically what everyone is struggling with,” said Fontan. “Someone might have pineapple leather and they have their own coating but it doesn’t mean it’s going to work on mushroom and so on.”

Unlike some companies, however, Osmose says it does not want to bring a product with a non-biodegradable coating to market.

“If you’re doing a composite, it will not biodegrade at the end of life, which is compromising all the good work that you’ve been doing before that step,” Fontan said.

Mycelium is one of the most popular emerging leather alternatives. It has already appeared in luxury goods such as a bag by Hermes, clothing by Stella McCartney and trainers by Adidas.

Reference

CornWall gives discarded corn cobs new life as interior tiles
CategoriesSustainable News

CornWall gives discarded corn cobs new life as interior tiles

Materials companies Circular Matters and StoneCycling have used corn cobs – one of the world’s most plentiful agricultural waste materials – to make interior cladding that is biodegradable and almost entirely bio-based.

Available in the form of tiles and sheets, CornWall is intended as a more sustainable alternative to ceramic interior wall tiles or plastic laminate.

The material is derived from more than 99 per cent renewable, biological sources, is created at low temperatures using mainly solar power and emits less carbon dioxide in its production than was captured by the corn as it grew, the manufacturers claim.

Photo of seven colours of CornWall tile in flatlay, ranging from a warm beige to a a muted reddish brown and a dark greenish grey. The tiles are arranged beside a bare corn cob, a full corn cob and a small bowl of shredded biomassPhoto of seven colours of CornWall tile in flatlay, ranging from a warm beige to a a muted reddish brown and a dark greenish grey. The tiles are arranged beside a bare corn cob, a full corn cob and a small bowl of shredded biomass
CornWall is an interior cladding material that is 99 per cent bio-based

To give the products a long lifespan, Circular Matters and StoneCycling have produced the tiles with a mechanical fixing system, so they can be demounted and reused or given back to the company for cleaning and recycling.

The technology behind CornWall was invented by Circular Matters – a start-up spun out of a lab at Belgium’s KU Leuven University, where founder Pieter Dondeyne and his team found a way to process plants to enhance their natural biopolymers and create durable materials.

The team then partnered with Dutch company StoneCycling to channel their technology into a product.

Photo of a person, close-up on their hands, holding a small pile of bare corn cobs, their kernels removedPhoto of a person, close-up on their hands, holding a small pile of bare corn cobs, their kernels removed
Corn cobs make up most of the composition of the tiles

StoneCycling co-founder Ward Massa told Dezeen that the focus on corn came because it is one of the most grown crops on the planet and its waste is abundant.

“What happens when you grow corn for human consumption is when it’s ready to harvest, you take off the corn and the corn cob is a leftover material because it doesn’t hold any nutritious value,” he said.

“Usually, that means that these corn cobs remain on the field and rot away, or they are burned as biomass to generate energy,” he continued. “In both cases, you release the carbon that was stored in those fibres – it rots away and it gets released, or you burn it and it gets released.”

With CornWall, the carbon is locked away until the tiles reach the end of their life and are left to decompose.

The production process begins with the discarded cobs being collected, dried and shredded into biomass.

This material is then mixed with other agricultural waste, binders and pigments and pressed into a plate material at a relatively low heat of 120 to 150 degrees. As a final step, the tiles are given a thin coating for water resistance.

All of the ingredients are derived from biomass apart from the pigment, which accounts for the 0.5 per cent of the product that is not bio-based – a very low percentage in a field where even products containing small amounts of materials of organic origin are sometimes labelled as bio-based.

Photo of a person at a distance standing in a huge warehouse of bare corn cobs piled high into hillsPhoto of a person at a distance standing in a huge warehouse of bare corn cobs piled high into hills
The agricultural waste material was chosen because of its abundance

According to Massa, the companies were able to keep the product pure by focusing on interior wall applications only.

“If you want to create a product that can also be used on the exterior or as a flooring or in the shower, then you have to start adding chemicals to bind it, to make it more water resistant and stuff like that,” he said.

“We chose to start with this application because it’s relatively easy and the binder and the product is nothing else than the natural polymers that are already part of this biomass. Because of adding heat and pressure, these polymers are activated and bind together.”

Photo of four objects in flatlay — a full corn cob on the left, followed by a bare corn cob, then a small tray of shredded biomass, then a CornWall tilePhoto of four objects in flatlay — a full corn cob on the left, followed by a bare corn cob, then a small tray of shredded biomass, then a CornWall tile
The corn cobs are dried and shredded before being pressed into tiles

CornWall is also biodegradable according to official standards, with Massa saying it could be buried in a field and disintegrate in a couple of months.

The only thing that would remain is the water-resistant coating, which is not biodegradable but makes up less than 0,001 per cent of the total product meaning it does not affect its biodegradability overall, according to Massa.

“Unfortunately there are no 100 per cent biodegradable coatings on the market yet,” he said. “We’re working with our suppliers on this but it’ll take more time.”

Instead, the intent is to keep the product in use for as long as possible.

The companies wants to target retail and hospitality chains that frequently open and close locations – Starbucks is an example Massa gives – and work with them to make sure the tiles stay in a closed loop of material reuse.

He also believes CornWall offers good options for these kinds of businesses in the design stage, as it can be ordered in custom colours and embossed patterns to complement their branding.

Photo of seven colours of CornWall tile in flatlay, ranging from a warm beige to a a muted reddish brown and a dark greenish grey. The tiles are arranged beside a bare corn cob, a full corn cob and a small bowl of shredded biomassPhoto of seven colours of CornWall tile in flatlay, ranging from a warm beige to a a muted reddish brown and a dark greenish grey. The tiles are arranged beside a bare corn cob, a full corn cob and a small bowl of shredded biomass
The tiles are available in a base range of six colours

“As far as we are concerned, this will become the new retail material,” said Massa. “Especially in those places in retail where they now use materials that are either glued or take a lot more energy to make or create a lot of waste when the shops are being renovated or demolished.”

“Production can also be done regionally because you don’t need a very complicated factory for it.”

CornWall is currently available in a base range of six colours and two sizes, developed in collaboration with Dutch design practice Studio Nina van Bart. Massa says additional textures will soon be added to the line.

CornWall is the fourth product from StoneCycling. The first was the WasteBasedBrick, which is made from 60 per cent waste and was used by Dutch architects Nina Aalbers and Ferry in ‘t Veld of Architectuur Maken to build their own house in Rotterdam.

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