The world of paper recycling is at a turning point. While graphic paper is increasingly disappearing, packaging materials are taking on a central role in the recycling process – but at what cost? White fibres, which were once a reliable raw material, are now highly contested. The SOLPACK forum at FACHPACK provided an ideal platform for discussing challenges and developments in the field of paper recycling. Axel Fischer from INGEDE, the International Association of the Recovered Paper Industry, focused on the technical hurdles in the recycling process and how the fibres can be kept in circulation.
Impact of Digitalisation
A decisive factor for the waste paper industry is the decline in graphic paper, such as newspapers and magazines. “Today, more people read on screens. This means that less graphic waste paper with a high proportion of white fibres is entering the recycling cycle,” explained Fischer. That is why there are now companies that even make toilet paper out of straw or recycled cartons. But an even more important resource for manufacturers are alternatives such as virgin fibres from packaging or the recycling of high-quality production waste.
“Packaging, especially that with a high proportion of virgin fibres, is becoming increasingly important as a raw material source for recyclers,” says Fischer, adding: “Since food cartons in particular have a high proportion of virgin fibres to counteract migration, this packaging is of course also attractive for paper recyclers.” He emphasised that these materials must be kept in the cycle in the long term: “We have to ensure that high-quality paper packaging is protected from downcycling so that the white fibres are preserved for as long as possible.” But packaging waste presents its own unique challenges.
Quality Requirements and Technological Advances
The quality of the waste paper is essential for the recycling process. Printing inks, adhesives and misplaced items are among the problems. Food residues or barriers in paper packaging can make recycling more difficult or impossible. “If fibres are upgraded with barriers or other coatings that are wet-strengthened, they no longer dissolve during recycling,” explains Fischer. On the other hand, films can usually be separated more easily. Fischer also focused on the problem of metallic coatings in paper packaging. While classic metal foils can be problematic in terms of recycling, tests have shown that metallised films with applied metallic pigments are significantly more recyclable.
Paper recycling in the paper mill begins with the pulping of the paper. Impurities are then removed. This is followed by the removal of printing ink (deinking), in which the ink is detached from the paper fibres and the ink is removed from the mixture – a key process in paper recycling. “It is not enough for the colour to be water-soluble, it must also be removed from the system or mixture so that the colour should not remain in the finished paper,” said Fischer. “This is only possible if the colour particles are hydrophobic and can be easily separated from the fibres and the mixture.”
In this context, Fischer emphasised that manufacturers should use tests such as the INGEDE deinkability tests or the CEPI method to check whether their products are recyclable.
Automated Processes and Future Perspectives
The sorting of waste paper is a crucial step in the recycling process. Due to the increasing proportion of packaging materials in the blue bin, the precise separation of white and brown cardboard is essential. Modern technologies such as AI-supported sorting systems are expected to provide solutions in the future. These developments are promising for improving the efficiency of sorting and minimising sources of error. After all, the quality of recycling stands and falls with the materials that are fed into the cycle. INGEDE stays on the ball with its research and practice-oriented advice, thus enabling adaptation to changing materials and challenges.
