Worldwide, it is estimated that paper consumption in 2022 has been around 415 million metric tons. Such a high consumption requires a large amount of available raw material resources.
Paper is produced with cellulose fibers, mainly from the wood of tree trunks. Cellulose is easily obtained by extraction, which can be both chemical and mechanical, from the vegetable fibers that are part of the trees.
These fibers are transformed into a dark paste, due to the presence of lignin, known as paper pulp. This paste will be washed, filtered and finally dried to proceed to its subsequent bleaching. With the bleaching stage, all the amount of lignin that could not be removed during the previous treatment of the pulp is removed. It is estimated that twice as many tons of wood are needed to manufacture one ton of bleached pulp obtained by chemical methods. On the other hand, if the extraction is carried out by mechanical methods, for every 10 tons of wood, 9 tons of paper pulp are obtained.
There are different methods for bleaching paper pulp. One of the most used consists of the use of peroxides (H2O2) as bleaching agents. During the bleaching process it is very important to remove all metallic traces from the water used in the paper-making process or directly from the wood itself, because these impurities could break down or destabilize the bleaching agent. To guarantee a longer duration and performance of the bleaching agent, chelating agents are added, eliminating metallic traces that can interfere negatively during the process.
After bleaching, the paste obtained is stretched, pressed and dried. Finally, a treatment is applied to the surface of the paper, it is placed in reels and cut according to the desired application and size.
Et voilá, paper ready to use!