The main output from the paper mills is of course paper. This includes about 2 kg of cores and plugs per tonne paper, which are considered and weighed as part of the net saleable product. The corrugated board plants produce corrugated board and boxes.
The average moisture content of the saleable product is 9% for Semichemical Fluting and 8% for Kraftliner, 7,5% for Testliner and Wellenstoff, 7-8% for corrugated board.
The main saleable by-products from the production of Kraftliner are tall oil and turpentine. These are included in the report.
All residues are reported as wet weight, separated according to their basic nature. Residues are only reported where they leave the system boundaries (i.e., where they are removed from and managed away from the site). As the mill is considered as a blackbox, energy and emissions associated with managing residues internally
(onsite) are included within the gate-to-gate inventory data. The waste treatment was not reported by all mills. From the residues of the recycled paper mills, which are mainly rejects from the pulp preparation, it is estimated that about a third is due to rejected materials that were associated with the previous use of the paper (for example, staples, paper clips, tags, adhesive labels, unrecovered fibres, etc). The remaining two thirds is material that is not in anyway associated with the previous use of the paper (for example, foreign items such as textiles, plastic packaging, glass, sand and grit, etc). Primary sludge from wastewater treatment in mills producing Testliner and Recycled Fluting are mostly recycled in the process and do not leave the site. Ashes, green liquor sludge and lime mud are commonly reported residues from the production of primary fibre-based paper. They are usually landfilled, but lime mud is also used as fertilizer. For corrugated board the main waste stream is paper for recycling, which is recycled and thus should not be called waste but recyclable material.
Allocation of residues to paper grades when a mill produces more than one paper grade
Data for material outputs are based on measurements. These have to be done because the mills have to pay for landfill and incineration or get paid for residues that are reused or recycled, like lubricants, according to the weight. When allocation was necessary, this was done according to mass of the different papers.