Weighted averages
The Annex presents the weighted averages of the inputs into and outputs from the sites (i.e., gate to gate) per tonne net saleable product for each paper grade and for corrugated board/boxes for 2020 from the participating paper mills and corrugated board and box making plants. It is important to understand that the figures do not represent a certain mill or plant with a certain technology. On the contrary the figures represent a “virtual mill” and a “virtual converting plant” utilising different technologies. The technology which is applied
in the participating paper mills and corrugated board plants is not the same.
For example: some mills use a combined heat power generation, some wastewater treatment is external, a large variety of additives is used. In some cases, this leads to a large variation of inputs and outputs between the mills. Furthermore, different inputs and outputs are strongly interrelated, so a mill can be high in one input compared to the others but low in another input, but a mill cannot be low or high for both. Therefore, no range of the data is given to prevent studies from being made using a false combination of highest and lowest data.
Due to confidentiality requirements by the mills, it is not possible to split input and output data per country. Similarly, a split in applied technologies is not possible.
In Table 4, the separate life cycle inventories for corrugated base papers and for corrugated board and
box production are combined to compile the life cycle inventory for an average tonne of corrugated boxes, considering both the production of the corrugated base paper and the conversion of the corrugated base papers into corrugated board and conversion of the corrugated board into boxes. For this average corrugated box scenario, the following composition has been assumed:
• Krafliner 14.6%
• Testliner and other recycled liner 45.1%
• Semi chemical fluting 1.8%
• Recycled fluting 38.5%
These relative shares are calculated from the relative consumption that is found in Table 1. The relative shares are used to calculate the inputs and outputs for the weighted average corrugated base paper. The paper production inputs and outputs are then multiplied with the average input of paper (1.12 tonne/tonne corrugated board product) and added up to the inputs and outputs per tonne of corrugated board product as reported in the Annex. This total includes the production of the paper that is used to produce the corrugated board, including the 12.0% losses that are reported as “paper for recycling”. It has to be kept in mind that the industry averages for inputs of paper, glue and starch are used. As previously highlighted, corrugated board boxes are far from standardised and inputs of paper, glue and starch depend on the box design.