Best Practices Report: Bale Storage
Proper bale storage can help maintain the quality of
prepared post-consumer PET plastics while improving safety in the
workplace. NAPCOR reports these "best practices" for the PET
intermediate processing industry. These best practices were developed
by the Association of Postconsumer Plastic Recyclers, the Clean
Washington Center for the Environmental Protection Agency, and NAPCOR.
Protecting Bale Quality
PET bale quality can be compromised by dirt, moisture, and
exposure to sunlight, which causes ultraviolet degradation of PET
plastic. Bales should be stored indoors, if possible, but if outdoor
storage is necessary, the bales should be completely covered to limit
exposure to the elements. Bales should be stored on pallets or clean,
dry surfaces to avoid contamination.
Handling Bales
Pushing bales directly across the floor can cause unwanted
contaminants to become embedded in the bale. For this reason, bales
should always be elevated off the floor surface while being
transported.
Stacking Bales
Poorly stacked bales can fall on workers or plant equipment,
causing serious damage or injury. Before stacking bales, an individual
should familiarize himself or herself with local fire codes and
building codes that apply to bale storage. For example, fire codes may
require proper clearances from sprinkler heads, clear aisles, and
unblocked points of exit. Building codes may limit the amount of floor
space that can be occupied with stored materials and the load impacts
for storage floors that are not on grade. These regulations are
strictly enforced by the federal Occupational Safety and Health
Administration.
Safe stacking procedures start with the first bale. The
bottom of a stack must establish a sturdy foundation for all additional
bales. If the stack will be placed against a wall, placing the bottom
bale roughly six inches away from the wall will allow upper bales to
lean into the wall and not toward workers and equipment. If the bales
are not stacked against a stationary wall, building a group of stacks
sequentially rather than finishing one stack to its maximum height will
allow nearby stacks to brace and reinforce each other.
Beyond these local regulations and stacking procedures, safe
stacking height in a facility is a function of bale integrity, bale
dimensions, and ceiling heights. The safety of everyone in the facility
relies on a firm understanding of these factors and an adherence to the
resulting stacking limitations.
Selling and Receiving Bales
Facilities that produce baled material for sale to other
reprocessors should weigh and "tag" bales prior to storage. This
procedure can help in weight determination during storage and solve any
potential weight disputes that might arise later. It will also assist
in ensuring compliance with legal shipping weights for road transport.
Facilities that receive bales should store them in distinct
"lots" organized according to the material's supplier. If inferior
quality material is discovered during processing and if punitive price
adjustments are necessary because of such quality problems, it will be
easier to identify the source of the material.
Best Practices Guidelines:
To protect the quality of PET bales and ensure safe storage,
follow these guidelines:
- Protect bales from particles, dirt, moisture, and
sunlight
- Elevate bales off floor surface during handling
- Know fire codes and building regulations for stacking
bales
- Stack the bottom bale at least six inches from nearest
wall
- "Build" stacks sequentially in small groups
- Weigh and "tag" bales prior to storage
- Store received bales in "lots" grouped according to
supplier
