A 45-year-old technology may become reality, in a completely new field. We’re talking about impulse drying of cellulose fibres, which within a few years could revolutionise the packaging industry. With energy-saving and efficient production, the first product may turn out to be – paper beer bottles from Carlsberg!
Impulse drying (or impulse technology) is a relatively old idea, which was developed in the early 1970s. It was developed in Stockholm by KTH Royal Institute of Technology and STFI, the predecessor of Innventia.
The idea was to see if it was possible to dry paper significantly faster than with traditional technology. Traditionally, paper is dried as follows: You drain the water as liquid by means of pressure or gravity. Any remaining water is then pressed out before the drying the rest. However, in the 1970s the thought arose: “What happens if we can dry the paper by pressing it at very high temperatures – over 200 degrees?”
What was sought was a faster process that was also more efficient, in other words using less energy. Impulse drying then took shape in Stockholm. There followed several research projects over a number of years. All major research institutes around the world have since researched impulse drying, including Innventia.
The last major investment in impulse drying at Innventia took place between 1996 and 2002. At that time there was a large project focusing on the FEX paper machine – incidentally, the only remaining machine that was still capable of performing impulse drying.
All the research arrived at was the following: Impulse drying of paper could work well – and provide several benefits. The technology can achieve a high level of dryness, better efficiency (less energy consumption) and also – it transpired – an extremely good, fine surface that is easy to print on.
However, there is one disadvantage: Unfortunately, there is too great a risk of things going wrong – and then the results can potentially be disastrous. The paper was liable to delaminate, which means that it ‘explodes’. The critical stage is when the paper emerges from the hot press. The resulting limitation in the process is so great that the method was not assessed as commercially viable.
Over the years there have been many attempts to research into impulse drying, but so far it has proved seemingly impossible to make the method entirely reliable. Then suddenly something happened.
In 2015, Carlsberg announced they were going to produce a paper beer bottle – with impulse technology one of the keys to production. And this within only two to three years! It was an innovation company in Denmark, Ecoxpac, that came up with the idea and three Ph.D. students are also currently working on the concept at the DTU, The Technical University of Danmark.
The announcement came almost 40 years after the original idea in the 1970s. Many people are asking: Can it be possible? And why now? The second question is easier to answer.
“For Carlsberg to raise the question of paper packaging is very much in keeping with the times,” says Marco Lucisano, who is Deputy Director of Business Area Material Processes at Innventia and who also has a doctorate in impulse drying. “As we previously explained here on the blog, the trend is increasingly towards a circular economy, which requires materials to be part of a constant cycle.”
Within impulse drying, little has happened, therefore, for 10 to 15 years – and now it may all become reality within the next few years. Why is that? Marco Lucisano explains:
“It will not be about paper, but an entirely new field, although using the same technology! The idea is fascinating, as are the possibilities. The difference here is that the material will likely be thicker than paper, while the process will be done at a slower pace than in conventional paper production. Imagine something like an ‘egg box in the shape of a bottle’. And who knows what more can happen in the wake of bottles? The only limit is your imagination.”
Here at Innventia we are looking forward to following developments and Carlsberg’s paper bottle! It bodes well that it is finally possible to move forward with the technology by changing field.
But what about ordinary paper then? Can’t impulse drying be reality even here, as it was originally intended? To this, all we can say is: “Never say never.”
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