Paper-Recycling System: Part 7

The highest rates of waste paper utilization are often gained by means of selective recycling: low-quality papers and high-quality waste. For large-scale recycling, however, other cases of recycling also enter the equation; this means processing low-quality, highly printed, and mixed waste paper to produce high-quality paper, which would require heavy cleaning technologies for recycled fibers. Increased cleaning and refining would, in turn, imply less fiber yield from recycled waste paper. Repeated and continuous large-scale recycling would potentially also increase the need for non-fibrous materials removal from waste paper, which also would reduce the average fiber yield.

In addition to fiber, either primary or recycled, varying amounts of different additives are used for base paper and board manufacturing. Additives are used for all paper qualities. Currently their relative mass, however, is very small in comparison with fibers except for printing-quality papers, for which they are currently estimated to have a furnish share of about 25%. As for volume, the important additives used are starch, calcium carbonate, and titanium dioxide. The concepts used in the ongoing discussion on paper recycling vary and are often different in meaning. In this feasibility study, the following nomenclature and concepts are adopted to distinguish between the main steps of the paper cycle. First, we have separated the production on base paper and board (bulk raw material) and the conversion (products usable for consumers). In general, the former is called paper and board production (manufacture) or base stock production and the latter paper product manufacture or conversion. The outputs are generally called base paper and board or base stock or paper products, respectively. Base paper and board is the bulk raw material for conversion. Regionally, conversion is supplied by the producers' base stock production and imports. Regional base stock production, in turn, covers both the needs for conversion industry and exports. Paper and board consumption takes the outputs from conversion and paper products as inputs.