Page 20 - Vol34No7 MarchApril2017

STATEWIDE By Ashley Cabrera
Plastic Bags: Clogging the System

During a normal day, the trucks the star axels, which sort the recyclables that become tangled in the equipment.
prepare to go out on their routes to by weight, along the screens, clogging Production would be greatly reduced to
pick up recyclables from businesses and the machinery. To the employees at a a non-sustainable rate in order to recover
residential properties. The loads arrive at sorting facility these clogs mean losing all bags from the stream and prevent
the recycling facility where they are sorted production time. “We have to stop wrapping in the machinery,” says Farley.
through by the employees, to eliminate sorting and spend about an hour each
trash or non-recyclables from entering day, cutting the plastic bags out of the If plastic bags cause so much trouble
the additional sorting processes. Many machinery by hand. In the amount of for the machinery, why can’t they just be
times, plastic grocery bags are thrown out time we spend dealing with these bags, hand-sorted before going through the
because it is not certain what is in the bag, an additional 20 to 25 tons of recyclables sorting screens? It is simply not logical to
and trying to find out would slow down could be processed during the time that pull out every single plastic bag before the
the sorting process. These bags might is used cleaning bags from equipment,” load goes through the sorting equipment.
include recyclables, but are now going said Paul Farley, Site Manager for Waste “There are too many plastic bags in the
to be sent to the landfill, because of that Management’s Nashville Materials loads for every single bag to be hand-
plastic bag. Recovery Facility. The plastic bags that are sorted out and it would slow down and
cut out end up in the landfill. If enough back up the process,” says Farley.
Many residents believe they are doing plastic bags get wrapped around the star
nothing wrong by putting their recyclables axels it can damage the sorting equipment, There have been attempts to rectify this
in a plastic bag. However, including plastic which leads to a significant financial loss. problem through different mechanisms.
bags with the other recyclables causes Other than this being a nuisance, cutting “Vacuum systems can be used for the
problems from the time they are put into the bags out of the machinery can also be retrieval of bags. These systems still
the recycling bins, to the point of sorting dangerous. “Due to the related hazards, require manual sorting to remove the bags
through the screens at recycling facilities. the employees must be trained on Lock from the stream. With current plastics
It may even prevent the recyclables from Out Tagout, which is used to ensure pricing there is not enough of a return on
being transported at all. “If the hauler dangerous machines are properly shut investment to justify purchasing this type
sees that there are a lot of plastic bags off. They also utilize fall protection to be of equipment,” says Farley.
contaminating the recycling bin, they able to safely enter and remove the bags
will not pick it up,” says Rachel Butzler, Rachel Butzler believes informing the
Solid Waste Project Manager for City of residents is critical to solving the problem.
Knoxville curbside recycling. “There needs to be more education for

After a load is hand-sorted by the
employees, it goes through additional
sorting to separate plastics, metals,
cardboard, and paper. Magnets catch the
metals, cardboard is separated by size,
and paper goes through two screens with
a fan underneath to keep it out of other
recyclable groups. Here is where plastic
bags start to cause problems.

Plastic bags are light weight—5.5
grams—and only weigh 1 gram more than
a piece of paper. Because of this similarity
in weight, they end up in the pile of paper.
Also, due to their clinging property,
when they are blown around by the fan
they hit cans and bottles, which sends
them into the pile of paper, instead of
proceeding through the sorting line. This
contaminates the load of paper and it is no
longer recyclable, sending it to the landfill.
The bags can also clog the openings of the
screens; when cans and bottles are sorted
through the screens, the bags go with
them and contaminate that load as well.

Any plastic bags that do not make it
past the sorting screens get twisted in

20 TPW March/April 2017