Mexican researchers have devised a system to convert used PET bottles used into, biodegradable mineral paper suitable for printing books or the manufacture of boxes and other stationery products. The recycled paper is made from recycled plastic bottles, calcium carbonate and rock, without the use of water or chemicals such as chlorine. This type of paper is stronger than plain paper, so much so that you it cannot be torn by hand, is waterproof and photodegradable. Also, it only absorbs only the necessary amount of ink during printing. It was conceived by some young researchers in Ecatepec, a city located to the north of Mexico City. According to the researchers, producing one ton of paper of this type can save over 20 trees and 56,000 litres of water compared to traditional paper production. In addition, the production process costs 15% less, as it requires no chemicals such as chlorine. Just 235kg of pellets of Pet are needed to produce a tonne of mineral paper. The pellets are obtained by crushing the plastic bottles and mixing them with calcium carbonate. The resulting material is then subjected to a thermal process, from which sheets of paper are produced. The idea was born from an effort to reduce the costs of production and avoid deforestation. Today, Mexico produces about 700,000 tons of paper per year to meet its domestic needs. About 33% of the paper produced is used for books and notebooks, 25% for paper, and the rest for toilet paper and food packaging. Mineral paper could be used in all these applications, with the only limitation being that it does not support alcohol-containing inks. Although there are already companies in Spain and Taiwan producing mineral paper using similar processes, the system designed by the Mexican researchers is four times less expensive.