In the wide world of agricultural waste lie many long and strong fibres that can be spun into textile yarns. Driven by demand for fabrics that have a cotton-like hand feel and by the plastic-free movement, pineapple, banana and even straw-derived materials are weaving their way into our wardrobes. Denim is an obvious candidate for these relatively coarse raw materials.

They come in many forms. Banana stem fibres can measure up to four metres, those of kapok seeds are considered too short to spin into yarn, the cellulose in wheat or rice straw is only a few millimetres long, but could, with adequate processing, become a viable raw material for a new class of biofibres. Some of these, abacá and jute, not to mention hemp and palm, have been used to make ropes, matting and roofing for centuries. The inherent strength of these fibres has made them a valuable resource for many indigenous communities. Their transformation into materials suitable for modern-day garment manufacturing and laundering may be a challenge but might also have the potential to offer a larger array of natural fibres for the denim industry.

In 2018, Swiss eco-brand Qwstion introduced Bananatex, a material derived from banana stems, into its collection of bags and accessories. The result of diligent research by company founders Hannes Schönegger and Christian Kägi, it is made from a wild banana plant, Musa textilis, also known as abacá, that grows in the Philippines and whose fruit is inedible.

“This genus produces a very strong fibre that can measure up to four metres in length, but it is fairly coarse and thick,” says CEO Hannes Schönegger. To make a fabric from these rustic fibres, the company applies a paper-making technique, known in Japan as washi washi. The sheets of paper are cut into fine filaments that are twisted into a yarn and can then be woven or knitted into a textile. The individual fibrils are 2 mm long, he adds, and this is what gives the fibre its resilience, high tear strength and abrasion resistance, perfect for backpacks. It does, however, tend to wrinkle, he notes.

Qwstion saw great potential in this new, yet old, textile and decided to make it available to others. “We were quite naïve,” says Mr Schönegger. “We received hundreds, even thousands of requests, and this took too many resources away from Qwstion.” To address demand, Bananatex was spun off into a stand-alone company to develop new applications and markets. One of these new markets could be denim, which is in the works and the first samples could be finalised this summer. “Denim is a logical step forward for us, as it is so prominent in fashion,” he says. To remain true to the 100% natural ethos of the company it would need to be dyed with natural indigo. The fabric will also need to undergo all denim laundering processes, such as enzymes, lasering and others. Mr Schönegger is confident it will work, but he admits it will face the challenge of pricing.

Production can be scaled, he says. Musa textilis plants grow in Ecuador, Costa Rica as well as the Philippines, where 80% of the rainforest has been destroyed. As part of biodiversity initiatives, it could provide small holder farms with a new source of revenue. “These banana plants need the shade of trees and the presence of other plants to thrive,” he says. “Thousands of hectares of land could be rewilded in the Philippines to supply fibre.”

It is nonetheless a rather expensive fibre, due to the manual labour involved in its production, and costs twice the price of organic cotton, says Mr Schönegger. “No economies of scale are possible, its transformation is either the result of human hands or diesel machines.” He does point out though that “the true cost of polyester, or even recycled polyester for that matter, is not reflected in its market price. Taking a macro perspective, Bananatex would not be more expensive than synthetics, as its real cost is not kicked down the road to future generations.”

Banana bonanza 

Banana fibres can also be extracted from the stems of the edible variety of the popular fruit, as does Pakistan-based Interloop. The company operates a facility in the Sindh province, where the fibre is harvested from banana farming waste. “Banana fruit farms in Pakistan generate some 10 million tonnes of waste annually that are usually burnt or discarded,” says Noor Jehan Sadiq, Interloop’s head of marketing. The company has built a fully integrated supply chain, from fibre extraction and processing to spinning a yarn it calls Loomshake. The 80% cotton/20% banana fibre blend yarn has been used to make denims, showcased in a capsule collection designed by Simply Suzette founder Ani Wells, and in a range of Guess jeans.

“A natural cellulosic fibre, it possesses good moisture absorption properties and dyes well, in addition to conserving land and reducing water usage typically associated with cotton growing,” says Ms Sadiq. She adds that it not only offers a solution for the disposal of biomass waste but also creates a new source of income for farmers.

Banana is not the only alternative natural fibre in Interloop’s product offering. It makes kapok/cotton yarns in various counts, with a maximum of 25% kapok fibre. Ms Sadiq says the company is also working on extracting jute fibre from post-consumer waste and exploring the potential of extracting fibres from corn and pineapple agro-industry waste.

Gencrest, a division of Indian conglomerate Samta Group, sees in banana crop waste the potential to make a man-made cellulosic fibre, which it has branded Vybrana. The company has developed a patented Fiberzyme technology to process the raw material and designed custom machinery for a manufacturing line that can produce up to 50 tonnes per month. Indian denim mills Arvind and Raymond UCO have integrated the banana-based viscose-type fibre into their collections.

Pineapples too

Pineapple leaves are another form of crop waste that is being tapped as a source of a new alternative natural textile fibre. Ananas Anam, a certified B Corp company based in London with production facilities in Spain, the Philippines, Bangladesh and the Ivory Coast, first developed Piñatex, a non-woven material combined with polyurethane. “But we always knew that fibre had the most potential and would be the best market application,” Riika Juva, head of communications and business development tells Inside Denim. The company founded in 2013 has been working on developing a method to make fibres suitable for spinning and building up a full supply chain.

Pineapple leaves produce a very long and strong fibre, drawn from the 20 or so leaves that grow around the fruit, and are usually left to rot, says Ms Juva. But the sheer volume of these leaves, an estimated 27 million tonnes annually, makes it impossible to leave them to rot on the field, which means that some 80% are burnt, she adds. Ananas Anam’s suppliers are both small holder farms and global organisations, such as Dole and Compagnie Fruitière.

In the production process created by Ananas Anam, the pineapple leaves are now collected and decorticated on the field. The biomass residues from this operation can be used as fertiliser, or sold for fuel, creating a potential third revenue stream for farmers, says Ms Juva. The textile fibre itself is obtained via a proprietary and patented enzymatic process that removes impurities. All further processing is purely mechanical, the company says. The resulting fibre is then marketed as Anam PALF, for PineApple Leaf Fibre, or spun by Ananas Anam’s spinning facility in Spain into Piñayarn. 

The fibre possesses high tensile strength and high moisture absorption due to its cellulose content. “It dries quickly,” says Ms Juva, “and is also a bit coarse.” It is most often blended with cotton or one of Lenzing’s manmade cellulose fibres, in proportions of 30% Piñayarn or Anam PALF. This keeps the price down and offsets the rusticity of the pineapple fibre. “As we have scaled, the price has come down, and can now be compared to linen, though this is still high for mass market applications,” she notes.

Both Piñayarn and Anam PALF are, again, good candidates for applications in denims. “They work well in blends with cotton, and they dye well too,” she says, noting that Ananas Anam partner mill Textil Santanderina has made denims in pineapple fibre blends.

The last straw

Earth Protex is a company that originated in the 1990s as a supplier of hemp, introducing the original alternative natural fibre to Levi’s, Nike, Patagonia and VF at the time. Founders Yitzac and Samuel Goldstein had previously co-founded Circular Systems, which they left in 2021. The father-and-son team is now expanding some of the technologies developed at the time on their own. AgRefinery, one of several research projects at Earth Protex, seeks to make the most of various types of crop waste by extracting micro and nanocellulose to produce fibres, films or coatings. The technology developed is not a viscose process, Yitzac Goldstein tells Inside Denim, but is rather similar to the method developed by Finnish company Spinnova. “We fractionate crop residues through various gentle processes to keep the polymer chains intact as micro and nano scale fibrils.” He believes it will be possible to extract a wide variety of compounds, from wheat or rice straw to sugarcane bagasse, corn stover or soy stems. Mr Goldstein says it is a “tunable” technology for fibres, in that they can be treated to be hydrophobic, hydrophilic, antimicrobial and so on. “We can produce a variety of ingredients,” he says. The research phase is ongoing, in collaboration with the Bio Products Institute of the University of British Columbia in Canada. Mr Goldstein expects staple spinning fibre, textile coatings and biopolymer additives to be commercially available by 2026. “We see great opportunity for cotton-like natural fibres,” says Samuel Goldstein.

The cellulose content of these alternative fibres should make them comfortable to wear and easy to care for. They should also benefit from the growing plastic-free and synthetic-free movement. And though cotton is the leading natural fibre, with a market share of 22%, its production has been stable over the past years. This leaves a wide-open space for a new crop of natural fibres direct from the farm.

Derived from abacá banana plants, Bananatex was developed by Swiss bag brand and material innovator Qwstion, in collaboration with a yarn specialist and a weaving partner in Taiwan.
Photo: Lauschsicht  

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