Laser un-printers could help save the trees

Laser 'un-printers' would allow paper to be re-used, reducing the need for virgin wood pulp

If you're concerned about deforestation, you likely blue-bin the no-longer-needed sheets of paper that have been run through your printer. You should keep in mind, however, that even though the recycling of that paper saves trees, the process still requires considerable energy, and most recycled paper still contains some virgin wood pulp. What would be better is if there were an "un-printer" that took the toner off of the used paper, so you would be left with a blank sheet that you could reuse. Well, thanks to research being conducted at the University of Cambridge, there soon may be.



The research was conducted by Dr. Julian Allwood, Leader of the university's Low Carbon Materials Processing Group, and PhD student David Leal-Ayala.

The pair started with regular Canon copy paper, which had text printed on it in HP Laserjet black toner. With assistance from The Bavarian Laser Centre, they then used a total of ten experimental set-ups, to see if lasers could be used to vaporize toner print from paper. Various intensities and pulse durations of laser light were tried, with spectra including ultraviolet, visible and infrared.

They concluded that lasers can be used for toner removal, without causing significant damage to the underlying paper - after the process has been repeated several times on the same sheet, however, some deterioration does occur. Additionally, they estimated that if toner removal was commonly carried out in most workplaces, the emissions produced by the pulp and paper recycling industry could be reduced by at least 50 percent. The need for paper production processes including forestry, pulping, paper-making and paper disposal would also be greatly reduced.

"What we need to do now is find someone to build a prototype," said Allwood. "Thanks to low-energy laser scanners and laser-jet printers, the feasibility for reusing paper in the office is there."

A paper on the research was recently published in the journal Proceedings of the Royal Society A.

Source: University of Cambridge via New Scientist