"Unprinting" to save paper

Posted on 23 October 2014.

Recycling paper is good, reusing it is better. Reduse has invented a technology that "erases" print on paper allowing it to be reused several times before recycling.

"Unprinting" works a bit like reverse printing. The toner is removed from the sheet using a pulsed laser ablation technique: an ultrashort pulsed laser removes words and images by heating the ink which literally evaporates. The process can be repeated three times without damaging the paper's fibers. This invention is the result of research by Dr. David Leal-Ayala, conducted under the supervision of Dr. Julian Allwood at Cambridge University.  It was published in the Royal Society's review, Proceedings in 2012.

"This could represent a significant contribution towards the cause of reducing climate change emissions from paper manufacturing", said Julian Allwood.

Contrary to what some experts predicted thirty years ago, computers and the Internet have neither led to the dematerialization of all documents nor a "paperless office". In fact, we have never used so much paper! According to Reduse, an employee uses around 10,000 sheets of paper a year. The environmental impact is huge! Although recycling has significantly developed, we can still do better. Especially since the recycling process requires a lot of energy and water (2,500 kWh and 5 - 6,000 liters of water per ton of recycled paper).

Reusing these thousands of sheets of paper before recycling would significantly reduce tree felling and remove several stages in the paper production cycle: pulping, manufacturing and disposal, limiting emissions from incineration or decomposition in landfills. This could result in an additional reduction of 50 - 80% of carbon emissions over recycling.

Find out more:

- Reduse
- Use a laser, save a tree
- Toner-print removal from paper by long and ultrashort pulsed lasers
- Saving Paper With “Unprinting” Technology