Science

Making from recycled paper a new paper

The letters have to go: printed paper, German and English scientists want to make reusable by you simply weglasern the printer color of the leaves. It should work best with green laser light: the colour pigments are simply evaporates with short flashes of light.

Instead of the waste paper disposed printed paper, on it will recycled such as toilet paper, you could rid it of printing ink and use it again. That in mind researchers at the Cambridge University and the Friedrich-Erlangen Nuremberg Alexander University. As they report in the Royal Society journal they are working toner using laser technology so thoroughly and at the same time gently by the paper to remove it is usable again.

How to make from recicle paper a new paper
Still alone every German consumes approximately 245 kg paper. For printed paper there is a recycling alternative: remove by laser printer color of the leaves. So 95% could save greenhouse gas emissions per ton of Office paper. These are about 25% more than conventional paper recycling.

Is not a new idea Making from recycled paper a new paper

Other scientists have tried and found that green laser beams with pulses in the nanosecond range remove toner from paper. Scientists from Cambridge and Erlangen were able to confirm these findings in their own experiments, but also found that visible green and infrared laser with Ultrashort pulses achieve remarkable results at toner removal.

Black printed copy paper as a test subject

Making from recycled paper a new paper is not a difficult technology. You tested a total of ten different laser procedure where a pulse frequency varied from nanosecond to the area of Ultrashort pulses (trillionth second) picosecond and femtosecond (second Billiardstel) and on the other hand the wavelengths of the radiation from the infrared range of visible light to ultraviolet range. Leaves from white standard copier paper, which was printed by an HP LaserJet printer with black toner served as subjects.

Toilet paper is made mostly from recycled waste paper.
Toilet paper is made mostly from recycled waste paper.

To check the results and to evaluate the paper was investigated after the lasers until on the atom. The scientists found that Ultrashort Pulse Laser with ten Pikosekundenpulsen both at a wavelength of 532? Nanometers – so in the range of visible green – as well at a wavelength of 1064 nanometers – so in the infrared range – best eliminated the toner without damaging the paper. The paper in a treatment was still white with green laser light (wavelength 532? Nanometer) with four nano second pulses – what previous studies confirmed. However this treatment isn’t quite as did well the cellulose fibers of the paper.

Conclusion: The paper treated with green or infrared Ultrashort Pulse Laser is as good as not damaged and Mint comes from the cleaning process. Both methods but slightly discolor the paper. The longer pulsed green lasers, however, provides deepest white – for the paper suffers more. Yet scientists think this procedure under the dash for the most optimal order to remove toner from paper.

Priced feasible and environmentally friendly

According to a research paper from the year 2012 “making from recycled paper a new paper”, the authors accounted that count on the purchase of a laser “Un-printers” – so a “discharge printer” when compared to traditional recycling, if he maximum £16,800 cost – equivalent to about €23.340. You thereby assume that high-quality recycled paper £0.03, so about 4 C per sheet at all costs. The authors quoted for the production of the recommended prototype of laser discharge printer with the best facilities (four nano second pulses and 532 nm wavelength) about 19 £000, say around 26 €380.

With regard to the environmental balance, the authors assume that you could save up to 95% GHG emissions per ton of Office paper, printed paper laser would clean. About the saving of greenhouse CO2 and other greenhouse gas emissions by the fact that four steps in the production of paper fell away would: forestry, the extraction of the pulp, the production and disposal of the paper. Conventional recycling save greenhouse gas emissions per ton of Office paper, however, only 76%.