It’s a freezing cold November morning in a forest outside Joensuu, eastern Finland. The assignment is to learn about the making of a one-of-a-kind dress. In a nod to the environmental theme of this year's Independence Day gala first lady Jenni Haukio will be wearing a gown made from Finnish birch trees to the event, by far the most-watched programme in the local TV calendar.
The journey of the dress from a Karelian forest to the red carpet at the Presidential Palace is a convoluted one that centres on a technology developed by Aalto and Helsinki Universities, called Ioncell. The Ioncell process produces fibres from cellulose, which comes from trees.
Aalto University makes the bold claim that Ioncell fabric is the "material of the future," because of its environmentally-friendly production process.
Sustainable forests and fabrics
Back in the forest, birch trees are felled as part of a thinning process. "We harvest some thinner trees so that the rest will have more space and light to grow," forestry expert Heidi Hämäläinen tells Yle News. "This is how much you need to make an evening dress," she says, picking up a skinny log. "About 75 centimetres."
The harvesting machine wields a single mechanical arm that throws whole trees around like toothpicks as Hämäläinen explains the approach to forestry management.
"Our forests are growing every year," notes Hämäläinen, adding that her employer, renewables industry giant Stora Enso, plants four seedlings for every tree that is cut down in final felling. Next, the logs are loaded on to trucks and driven to Stora Enso’s Enocell mill in Kontiolahti, around an hour from Joensuu.
Story continues after photo.
Wood is big business in Finland. Stora Enso’s sales last year totalled some 10 billion euros, and the company employs 26,000 people around the world. It’s investing 52 million euros to completely overhaul the Enocell mill for the production of 'dissolving pulp' - the main ingredient in Haukio’s dress as well as in other items such as sausage casings and sponges.
"The most important end-use for our dissolving pulp is in the textile industry," says Sirpa Välimaa, product manager of dissolving pulp at Stora Enso. "Wooden fibres have great touch and feel, a shininess, a great lustre and drape as textile fibres."
For Välimaa, the main benefit, however, is sustainability. "It’s a fully renewable raw material, unlike petroleum-based polyester," she says, "And they also solve a sustainability problem that cotton has, because it needs a lot of irrigation."
According to Välimaa, it takes 7,000 litres of water to make a pair of jeans out of cotton. By contrast, she claims, using the wood fibre Ioncell technology developed by Aalto and Helsinki Universities would use 97% less, saving the same amount of water the average person would consume in ten years.
From paper to fabric to gala gown
Once the birch timbers have been shredded into small chips, liquefied in vast digestion tanks, dried out and cut into sheets resembling huge swathes of paper, the next step in making a dress out of birch trees takes place at Aalto University campus, in Espoo.
Staff scientist Michael Hummel explains the process. Take the sheets delivered by the pulp mill and grind them into powder. Mix the powder with the non-toxic ‘ionic liquid’ that gives the Ioncell process its name and produce a dark, reddish, resin-like substance called ‘spin dope’. The spin dope can then be spun into fibres which are themselves then woven into a yarn - the basic starting point for fabric.
"Although I’ve been involved in the production process, this is the last thing I see," says Hummel, holding a bundle of the unwoven fibres. "Everything after that will be entirely new for me."
That’s because the design of the dress itself has been a closely-guarded secret. Two Aalto University students, Emma Saarnio and Helmi Liikanen, designed the dress that Jenni Haukio will wear at the Independence Day Gala on 6 December, but they’re not giving anything away.
"Of course we have each other," says Saarnio, "So we don’t have to keep it all inside!" interjects Liikanen. "It’s not just us, this is a big team with this whole project," Saarnio continues, "So we have had a lot of people we can discuss this with."
Overseeing that team is Professor Pirjo Kääriäinen of Aalto University’s Department of Design. "It’s a long research project, running almost 10 years," she says of the university’s work on Ioncell, "a long, long process that is still going on."
Ioncell isn’t commercially available yet - the material for the first lady's dress was produced in an Aalto University laboratory.
Kääriäinen is asked if the dress itself is a kind of experiment, and she frowns. "She’s going to be wearing a beautiful gown, that’s the point."
Tune into Yle TV1's live broadcast of the Independence Day Gala from the Presidential Palace at 6.00pm. The festivities will also be streamed on Yle Areena.
Edit: Story updated at 11.32 on 6 December to specify that four seedlings are planted for every tree cut in final felling.