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MPhil in Engineering for Sustainable Development

global challenges, engineering solutions

Studying at Cambridge

Jonathan Cullen

Technologies for the Reuse of Printed Paper in the Office

Jonathan Cullen

Technologies for the Reuse of Printed Paper in the Office

 

Climate change gas emissions from the paper industry are significant and growing.  Global production of cut-size papers in 2001 alone will result in 100 million tonnes of carbon dioxide equivalent emissions; emissions are projected to increase 10-fold over the next 50 years.  Potential exists to reduce emissions from cut-size papers through the reuse of printed paper in the office.  Creative thinking techniques were used to perform a broad based search for reversible printing technologies (those which allow for repeated printing and un-printing of paper).  The result was a Catalogue of Reversible Printing Ideas, prioritised according to their re-print potential.

A programme of experimentation was undertaken to: measure contrast removal from a range of print/paper combinations, optimise the removal process and assess the re-print potential of promising combinations.  Contrast was removed using an existing abrasion method and a newly designed scraping technique.  Results show significant variation in contrast removal across the print/paper combinations (10% to 100% for abrasion and 12% to 98% for scraping).  The microporous absorption layer in photo-paper was found to be abraded sacrificially producing exceptional unprinting results.  Toner print was completely removed from transparency film using the scraping mechanism; five re-print cycles were achieved with no visible damage sustained to the film.  This rivals conventional offsite recycling techniques.

Experimental results show that a technology for the reuse of printed office paper is still technically feasible.  Further research should seek to develop a demonstration-level desktop-machine for use in the office.