Paper-Recycling System: Part 13

In addition, in recovery there are fiber losses in the usable percentage of fibers, which correspond to about 5%. Considering these practical limitations, a theoretical maximum share for reuse fibers in the overall furnish, with a 100% collection rate for all waste paper, can be estimated at 75% to 80% depending on the maximum number of the reuse cycles accepted.

However, the maximum collection rate cannot reach 100% because of long-term products, household papers, and paper exports. Excluding the part which is not recyclable and assuming a 100% collection rate for the rest, theoretically a 65% to 70% overall furnish share could be reached. In practice, the collection rate is never that high. The highest level that has been achieved so far is 55% in the Netherlands. Under these conditions, a furnish share of about 50% seems achievable as an average for Western Europe. However, the utilization of waste paper fibers in some European countries has risen to 65%. This can be explained by a consumption-dominated paper balance and by waste paper imports.

Depending on the average age of the recycled fibers used in the furnish, the thickness of the base paper or board should be increased to maintain the required strength and scoring level. Alternatively, undersized fibers could be screened out of the stocks; however, because other fiber properties are also involved, such as strength, scoring, and folding, screening alone would not necessarily guarantee the adequate properties. It would also mean a smaller yield of fibers because the oldest part is always screened out or dissolved. The normal solution to achieve the properties required is to add primary fibers to the furnish either by mixing them with reuse fibers or by assembling the paper as layers of different quality fibers. The specific weight of papers in the cases where recycled fiber is used tends to be 5% to 15% higher than in the cases where only primary fibers are used.