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Sustainable Industrial Design and Waste Management
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TABLE 5.3
Worldwide Usage of Waste Paper (McKinney, 1991)
Year Pulp and paper Wastepaper Apparent
production (m ton) consumption (m ton) utilization rate (%)
1986 202 63 31
1990 237 85 36
1991 239 91 38
1992 246 96 39
2000 307 138 45

TABLE 5.4
World Recovered Paper Utilization (Kilby, 2001; CEPI, 1999)
Country Recovery (000 ton) Utilization rate (%)
EU 34,988 44
USA 32,943 38
Canada 4,810 26
Japan 16,378 55
Brazil 2,295 35
Mexico 3,395 93
Australia 1,463 58
Others 9,759

recycling a huge reduction in both the volume of waste and the greenhouse
effect would result, in addition to saving water and energy, which will help
in having a better environment.
The process of paper making starts with fiber slurry preparation. First,
fibers are mechanically and/or chemically pulped, and then a digester is used
for cooking the cellulosic fibers. The resulting pulp is screened to remove
undigested fibers, impurities, and any undesired particles. Pulp is then intro-
duced through washers for separating pulping chemicals. Bleaching or treat-
ing the fibers with chemical agents is necessary to increase the brightness of
the pulp. Pulp refining or beating is then carried out to increase the strength
of the fiber to fiber bonds and accordingly increase the strength properties of
the produced paper. The resulting pulp slurry is then applied to a fine screen
for forming; water is allowed to drain by means of a force such as gravity or
pressure difference developed by water column. Pressing after draining is
then necessary for further dewatering by squeezing water from the sheet and
finally drying the sheet by air or by passing it over a hot surface.
Two hundred and eighty years ago the paper industry introduced the
concept of paper recycling because recycling is considered to be more cost
effective than incineration or landfilling. This demonstrates the importance
of paper recycling in the paper manufacturing process. Worldwide paper
recycling has been improving since 1986 as shown in Tables 5.3 and 5.4.