Lasers can 'unprint' documents

CAMBRIDGE, England, March 15 (UPI) -- British researchers say they've developed a laser process that can "uncopy" toner ink from paper as an alternative to traditional recycling.

Scientists at the University of Cambridge say the process involves short laser pulses to erase words and images by heating the printed material to the point that it vaporizes.

The technique works with commonly used papers and toner inks and is more eco-friendly than recycling, they said.

"When you fire the laser, it hits the thin toner layer and heats it up until the point that you vaporize it," researcher David Leal-Ayala told the BBC.

"Toner is mostly composed of carbon and a plastic polymer. It's the polymer in the toner that is vaporized."

Tests carried out on the resulting "unprinted" paper suggested it had not sustained significant damage and was "comparable to blank unlasered paper," the researchers said.

Reusing rather than recycling paper would be good for the environment, they said.

"When you recycle paper you use a lot of resources," Leal-Ayala said.

"You use electricity, water and chemicals, and to be honest when you print something the only reason that you don't re-use the paper is because there is print on it.

"The paper is still in good condition and there is no point in going through all the heavy industrial process if the paper is still perfectly fine."