Over half of the paper consumed in the United States is now recycled, a steady improvement on the situation during the 1990s, but progress is slower than it could be. Now a new building material has the potential to create a huge new demand for waste paper that could help push the rate up faster than before.
A team at the University of Nottingham in the UK has developed a new composite material based on shredded waste paper. Long, fine strands of paper are bonded together under high pressure using a sodium silicate gluing agent, resulting in a material that’s as strong as the particle board often used for interior walls, ceilings and other non-load bearing structural components. In other ways it’s superior to particle board. The use of sodium silicate makes the new material resistant to flame and moisture, which has obvious safety advantages for a construction material. Additionally it can be used in many environments where particle board is unsuitable. Particle board has a tendency to discolor when exposed to moisture; in extreme cases it can distort, swell or even disintegrate. The bonding process means it can also be molded into different shapes. One option is to mold it with a ribbed surface, giving much greater structural strength for the same weight of material. Most particle board comes as flat boards or strips, so the pressed paper alternative is more versatile and could well turn out to be more durable, too.
MDF itself is a fairly sustainable material; it’s manufactured from chipped softwood, almost all of which comes from managed forests. In terms of carbon, locking up atmospheric carbon in trees then finding a permanent use for the trees has a positive impact. The environmental benefits mostly come from the potential for recycling more paper. Currently paper that isn’t recycled often ends up in landfill. The fact that paper is biodegradable is often cited as an advantage, but biodegradation often simply means decomposing and releasing carbon back into the environment. It’s much better if the paper that’s currently dumped or incinerated is locked up in buildings instead.
The new process is also a lot more efficient than conventional paper recycling. To turn waste paper back into usable pulp requires multiple steps and can be quite energy intensive. Producing anything apart from low-grade packing materials also often means the use of bleaches and other chemicals. None of that is necessary to turn it into the new particle board substitute – it simply has to be finely shredded. That requires a lot less energy.
With current paper recycling in the USA standing around 54 percent there’s a lot of potential for expanding into new applications. Waste paper is also exported, but even when that’s taken into account tens of millions of tons goes to landfill every year. Anything that reduces that is worth pursuing. There’s no word from Nottingham yet on when the product will be licensed for manufacture, but it’s based on existing and easily reproduced technology so it shouldn’t be too long.