Researchers Design New Unprinting Method to Reduce Environmental Pollution

If a printer could feature an “unprint” button that uses pulses of light to erase toner, then this could curb environmental impacts when compared to traditional paper recycling.

A research team, led by Rutgers University, has developed a new method to unprint paper that, different from laser-based methods, can work with the standard, coated paper used in office and home printers. A study, published in the Journal of Cleaner Production, has revealed that the newly developed method used pulses of xenon light to remove blue, black, green, and red toners without causing any damage to the paper.

Our method makes it possible to unprint and then reprint on the same paper at least five times, which is typically as many times paper can be reused with conventional recycling. By eliminating the steps involved in conventional recycling, our unprinting method could reduce energy costs, pollution and greenhouse gas emissions.

Rajiv Malhotra, Assistant Professor, Department of Mechanical and Aerospace Engineering, School of Engineering, Rutgers University, New Brunswick

Malhotra is a coauthor of the study.

The study also showed that traditional recycling of coated paper was a major cause for chemical pollution, climate change emissions, and energy use. Extended lifetime of paper and no recycling steps would be of significant benefit to the environment.

Later, the scientists refined the method to a greater degree by testing more toner colors on various paper types. Unprinting can be carried out by using simple equipment and by wiping with an extremely small quantity of benign alcohol. The scientists are exploring ways to combine unprinting with typical home and office printers.

Michael Dexter, a former Rutgers engineering doctoral student, is the lead author of the study. Keri Rickman, former undergraduate engineering student, and scientists at Oregon State University collaborated to contribute to the study.