The process of making baking papers starts in the forest. Paper is produced from wood fibres, which in professional language is called pulp. The fibres are separated from the other components of wood in the pulping process. Wood fibres are naturally white, but lignin, a compound found in trees, turns them brown. To make the pulp white, it must be bleached. In the bleaching process, the lignin is removed from the fibres and later utilised in energy production.
The environmental issue with bleaching dates back to the times when it was done with chlorine gas. The gas was detrimental to the environment and dangerous to use. Therefore, its use was stopped already in the 1990s. Today, pulp is bleached with chlorine dioxide, oxygen and peroxide. These are not harmful to people or the environment. Furthermore, in modern pulp production, there are more closed loops than before. This means, for example, that the chemicals used are recovered and circulated for re-use. This certainly helps in achieving minimal emissions.
Bleaching is like washing the pulp. Unbleached fibres may cause odours and tainting in paper products. There is a risk that these might contaminate food that is in contact with the paper, particularly if high temperatures are involved. Baking papers are typically placed in ovens or steamers. Clearly, in this sense, white is a hygienic choice.
The majority of the pulp produced globally is white, and this is also the case with Metsä Group. Its pulp mills in Finland are modern and emission levels very low in comparison with mills worldwide. This is why we like to use our own pulp for producing baking papers. We want to be sure that our environmental performance is first-rate.
Sustainability is a broad concept. The best solutions are the ones which are good in several aspects: environmentally, socially and economically. Today, white pulp is not an environmental problem as no harmful bleaching chemicals are used. White baking paper is a hygienic choice and safe for people to use. And in Metsä Group’s case, the main raw material – wood – is fully traceable to its origin and it naturally comes from sustainably managed northern forests.