Plastic paper and disappearing ink


Toshiba has developed a printer that uses ‘paper’ made from plastic which can be reused hundreds of times.
The unveiling joins recent efforts by office products scientists to create environmentally friendly, reusable paper.
The electronics manufacturer said the machine was designed for businesses and could be used in offices where permanent copies of documents were not needed.
Paper used by the B-SX8R is made from a plastic called polyethylene terephthalate or PET – the same substance used in bottles of fizzy drinks. A layer of heat-sensitive chemical pigments is laid over the surface which, under different conditions, can turn from black to white.
Changing the temperature applied to the unique pigment makes it possible to write and erase text or graphics. The printer can produce up to 12 sheets per minute and has a resolution of 12 dots per mm or 300 dots per inch.
Mike Keane, European product manager at Toshiba TEC, said the paper could be comfortably reused 500 times under normal conditions.
"The B-SX8R will help to reduce paper use, preserving forest resources and reducing CO2 emissions during both paper manufacturing and waste processes," Keane in a statement.
Direct thermal printing uses no consumables such as inks, toners and drum cartridges. The user prints, then replaces the re-writable paper into the printer and reprints. The re-writable sheets can be cleaned using a special sheet cleaner to remove oils and fats that may contaminate the paper, extending the life of the paper and ultimately the printhead.
Toshiba, which made it on to a list of the top ten green companies produced by global mutual fund Portfolio 21, also claims the printer uses lower C02 emissions during paper manufacture and waste processes. CO2 emissions for normal paper currently stand at 6.5kg per 1,000 sheets against 1kg per 1,000 sheets for re-writable paper.
Copier and printer manufacturer Xerox has also been hard at work in the lab, and recently developed an experimental paper which erases itself. Scientists have invented a way to make prints whose images last only a day, so that the paper can be used again and again.
The company says the technology, which is still at the preliminary stage, could ultimately lead to a significant reduction in paper use.
The experimental printing technology, a collaboration between the Xerox Research Centre of Canada (XRCC) and PARC (Palo Alto Research Center) could someday replace printed pages that are used for just a brief time before being discarded.
Xerox estimates that as many as two out of every five pages printed in the office are for what it calls ‘daily’ use, like emails, web pages and reference materials that have been printed for a single viewing.
"Despite our reliance on computers to share and process information, there is still a strong dependence on the printed page for reading and absorbing content," said Paul Smith, manager of XRCC’s new materials design and synthesis lab.
"Of course, we’d all like to use less paper, but we know from talking with customers that many people still prefer to work with information on paper. Self-erasing documents for short-term use offers the best of both worlds."
To develop the patented "erasable paper", researchers needed to identify ways to create temporary images. The company said that the "Aha" moment came from developing compounds that change colour when they absorb a certain wavelength of light, but then gradually disappear. In its present version, the paper self-erases in about 16-24 hours and can be used multiple times.
While scientists at XRCC are working on the chemistry side of the technology, their counterparts at PARC are busy investigating ways to build a device that could write images onto the special paper.
PARC researchers managed to develop a prototype printer that creates the image on the paper using a light bar that provides a specific wavelength of light as a writing source. The written image fades naturally over time or can be immediately erased by exposing it to heat.
While potential users have shown interest in transient and innovative documents, Xerox realises that there is still much to be done if the technology is to become commercially attractive.
"This will remain a research project for some time," added Eric Shrader, PARC area manager, industrial inkjet systems. "Our experiments prove that it can be done, and that is the first step, but not the only one, to developing a system that is commercially viable."