Up until now, the only International Standard that specified the requirements for paper permanence was ISO 9706 according to which, in order for paper to be classified as permanent it shall have a lignin content of less than 1%. The limitation on lignin content in ISO 9706 has – until now – excluded the presence of modern pulps such as high-yield chemical pulps, BCTMP, APMP (alkaline peroxide mechanical pulp) and most recycled pulps from paper products classified as “permanent” according to the requirement of ISO 9706. However, based on research findings on paper permanence over the past 20 years, we know that such pulps can be used in a wide range of paper products for general graphic applications with no significant loss of mechanical properties over long storage periods.
In order to respond to market demands for an International Standard applicable to mechanical and high-yield pulp products, Canada, through FPInnovations, has taken the initiative to develop a new ISO Standard that specifies the requirements for the stability of paper for general, graphic applications.
As an important part of the development of this new Standard, an international round robin study, involving accelerated ageing of paper, was conducted in 8 laboratories from 7 different countries. The results were entirely consistent with previous research results, indicating that neither the mechanical nor optical properties of paper, over a 0-79% range of mechanical pulp content, were significantly impaired during long term storage.
The new Standard was published in December 2017 as ISO 20494: Paper – Requirements for stability for general graphic applications. This new Standard will open up opportunities for mechanical and high-yield pulp producers and paper manufacturers worldwide, and particularly in Canada, to develop and market a wide range of paper products containing mechanical fibre, as well as recycled fibre.
The benefits of using mechanical fibre and/or recycled fibre in paper products range from improved paper performance – particularly paper opacity – and lower production costs, to higher sustainability and greatly-reduced environmental footprint. In particular, the amount of virgin fiber, energy consumption, use of water resources, levels of GHG and other emissions, and solid discharge are significantly lower with the addition of high-yield pulp and/or recycled pulp in paper production.