Page 432 - Solid Waste Analysis and Minimization a Systems Approach

410 PLASTIC AND RUBBER MANUFACTURING

Where the origin of the material is industrial scrap, the recovered end product is gener-
ally referred to as reprocessed to distinguish it from recycled material, which is derived
from genuine postuse products. There is also some recycling of plastics products which
have undergone a full service life and have then been reclaimed for further use. Material
of this type is called postuse material. It can arise from industrial, commercial, and
domestic sources. Recent years have seen a growth in postconsumer plastics recycling.
Most of the plastics recycled are from the commercial and industrial sectors, with
bottles being recovered from domestic sources. This pattern is because the main
requirements for effective recycling of postuse plastics are

■ Resource-efficient reclamation of the postuse products
■ Facilities to sort and compact the reclaimed products
■ End-use applications for the recycled plastics materials and these conditions are
more easily met from commercial postuse waste

In addition, heavily contaminated plastic waste requires special washing and drying
facilities.
According to the American Plastics Council (APC), more than 1800 U.S. businesses
handle or reclaim postconsumer plastics. Plastics from MSW are usually collected
from curbside recycling bins or drop-off sites. Then, they go to a material-recovery
facility, where they are sorted either mechanically or manually from other recyclables.
The resulting mixed plastics are sorted by plastic type, baled, and sent to a reclama-
tion facility. At the reclamation facility, the scrap plastic is passed across a shaker
screen to remove trash and dirt, and then washed and ground into small flakes. A flota-
tion tank then further separates contaminants, based on their different densities. Flakes
are then dried, melted, filtered, and formed into pellets. The pellets are shipped to
product-manufacturing plants, where they are made into new plastic products.
In 1997, APC estimated that roughly one-half of all U.S. communities—nearly
19,400—collected plastics for recycling, primarily PET and HDPE bottles, such as
soda bottles. Roughly 7400 communities collected plastics at the curb, and approxi-
mately 12,000 communities collected plastics through drop-off centers.
While overall recovery of plastics for recycling is relatively small—1.4 million
tons, or 3.9 percent of plastics generated in 2003—recovery of some plastic containers
has reached higher levels. PET soft drink bottles were recovered at a rate of 25 percent in
2003. Recovery of HDPE milk and water bottles was estimated at about 32 percent
in 2003. Significant recovery of plastics from lead-acid battery casings and from some
other containers also was reported in 1999.
Plastics are recycled for both economic and environmental reasons. Recycling and
reuse of plastics have the obvious benefit of decreasing the amount of used plastics
that end up in landfills. With increased plastics recycling, fewer natural resources need
to be extracted to produce virgin plastic.
According to APC, plastics production accounts for 4 percent of U.S. energy con-
sumption. Though they are derived from nonrenewable natural resources, plastics’
adaptable characteristics often enable manufacturers to reduce the material used, energy
consumed, and waste generated in making a variety of products.