New Zealand footwear brand Allbirds has snared Oscar-winning actor Leonardo diCaprio as an investor and also announced its own twist to a Kiwi classic in the form of an environmentally-friendly range of jandals.

The amount invested by the Hollywood star, known for films such as Titanic and the Great Gatsby, was not disclosed.

Allbirds, co-founded by former All Whites captain Tim Brown, also announced it had developed its own carbon-negative green ethylene-vinyl acetate (EVA) foam, derived from sugar cane sourced from southern Brazil.

The company, which calls the material SweetFoam, hopes the invention will revolutionise the global footwear industry, which churns out an estimated 25 billion pairs of shoes a year, with approximately 300 million pairs discarded annually.

It's an issue close to the brand's heart.

Brown and co-founder Joey Zwillinger, an engineer and renewables expert aim to introduce the SweetFoam across its product offerings before encouraging the entire footwear industry to follow suit, allowing the open-source use of the special green EVA ingredient.

"The specific component itself is actually a carbon negative component," explains Zwillinger.

"This means it takes more carbon out of the atmosphere than it actually uses to produce this particular foam. So for us, it's about getting very close to the idea that we are putting something on the planet that does something positive, versus just taking from it. It's the overarching driver for everything we do at Allbirds — from our product development to a sustainability perspective. We track our impact on the world."

Proud to be an investor in @Allbirds, a company dedicated to creating a more sustainable future by developing new materials and serving as a model for the footwear industry. Learn more: https://t.co/hmAn6cqdg5.

— Leonardo DiCaprio (@LeoDiCaprio) August 1, 2018

Debuting in 2016 with a line of sneakers made from Merino wool, the brand introduced its second category made from Eucalyptus trees earlier this year.

"Although wool has been a critically important and central component of how we started, two years later we added a eucalyptus tree fibre in response to our consumers who wanted something a little different to wear in hot conditions," explains Zwillinger.

"It's always been about solving consumer problems using a renewable material. This third phase of the sugar cane is a great example of being transformative from a sustainability perspective, but is also simply an incredibly comfortable experience."

Inspired by Japanese-style zori jandals, the Sugar Zeffer is an example of the SweetFoam in its purest form.

Developed by the brand's product development team in conjunction with its sustainability department, the design was led by another clever Kiwi, Head of Design Jamie McLellan. The jandals are available in four key colourways, inspired by nature and New Zealand's native birds.

"The goal is to extend the foam to all our footwear, but we're starting with a jandal, flip-flop, thong or a zori — whatever you want to call it, depending on where you come from," laughs Brown. "The zori is an iconic Japanese sandal dating back to the 11th century, and jandal I think is a portmanteau of Japanese and sandal, so it's become this iconic Kiwi piece of footwear."

"Part of Jamie's design ethos is to take these classic things and simplify them to its base of comfort and materials. He's had his eye on this particular product for a long time and I think it's one of those things that has been commoditised, cheapened and forgotten about. Jamie has really tried to rethink that and change the way we look and wear things. I think it's one of our greatest design feats and a great showcase for this material."
Featuring interchangeable straps made from four materials: recycled plastic bottles, bio-suede, bio-foam, bio thermoplastic polyurethane (TPU) the straps were also made with the help of one of the largest manufacturers of bras.

Indeed, the SweetFoam and its showcase product of the Sugar Zeffer jandal is a major turning point for the brand whose growth rate has been exponential: in 2017, industry sources reported the company had US$50 million in top-line revenue, with business looking to double that this year and attracting a new stream of investors in the process including Golden State Warriors basketball star Andre Iguodala; along with the addition of a new board advisor, Neil Blumenthal, CEO of eyewear giant Warby Parker.

The new Sugar Zeffer range, available to purchase from today, comes on the back of last week's major news for the brand — the forthcoming expansion into the UK market in October. Available already in the US, New Zealand, Canada and Australia, the UK expansion is an answer to growing consumer demand, and will be overseen by the brand's recent appointment of a new international president, Erick Haskell. It's rapid growth trajectory is testament to growing consumer demand for well-designed products that are friendlier to the planet, and for Brown, it's only a matter of time before a real shift happens.

"Outside of the fossil fuel industry, the fashion industry is the largest contributor of carbon emissions into the environment," says Brown.

"That's a real problem. 25 billion pairs of shoes are made globally each year. Americans buy an average of seven to eight pairs of shoes per year, and it's a category that's paid lip service to the idea of sustainability. There's still a disconnect. Consumers say they care about it, but when it comes to the purchase moment it doesn't always impact the way people buy — but I think that's starting to change."