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The basic design for recyclability guideline to consider
when making material choices for any attachment to the bottle
is to consider its general compatibility with the base resin
(PET) or the removal efficiency in conventional water-based
separation systems that separate plastics by density. Attachments
may include closures, closure liners, base cups, inserts,
labels, pour spouts, handles, sleeves, safety seals, coatings
and layers. PET has a density greater than 1.0 and will sink
in these systems. For efficient separation and removal in
conventional sink/float separation systems, attachments should
be made from materials with a density less than 1.0 or otherwise
be compatible with PET in the reclamation process. Materials
with a density less than 1.0 will float in these systems and
can be separated easily from the PET. (Density
range of key plastic materials.)
The use of PVC attachments of any kind on PET bottles is undesirable
and should be scrupulously avoided. These attachments generally
include, but are not limited to closures, closure liners, labels,
sleeves, and safety seals. Very small amounts of PVC (in the
parts-per-million range) can severely contaminate and render
large amounts of PET useless for most recycling applications.
In addition, PVC is very difficult to separate from PET in conventional
water-based density separation systems, due to similar densities
(greater than 1.0) that cause both to sink in these systems.
Plastic closures made from PP or HDPE – in that order –
are preferred to all others, as they are separated most easily
from the bottle in conventional separation systems. Closure
systems that contain no liners and leave no residual rings or
attachments when removed from the bottle are also preferred.
The use of PVC for closures or closure liners is undesirable
and should be scrupulously avoided. While the use of EVA closure
liners in plastic closures is acceptable to many reclaimers,
EVA liners can cause contamination problems when used in aluminum
closures. In general, the use of aluminum closures should be
avoided, as they are more difficult to separate from the bottles
compared to preferred closure systems (PP and HDPE) and add
both capital and operating costs to conventional reclamation
systems. Closures made from PS or thermoset plastics are undesirable
and should be avoided.
If tamper-resistance is required in specific product applications,
it should be an integral design feature of the bottle. The use
of tamper-resistant or tamper-evident sleeves or seals is discouraged
as they can act as contaminants if they do not completely detach
from the bottle, or are not easily removed in conventional separation
systems. If sleeves or safety seals are used, they should be
designed to completely detach from the bottle. The use of PVC
sleeves or safety seals is undesirable and should be scrupulously
avoided.
Traditionally, unpigmented PET has the highest value, and the
widest variety of end-use applications. Transparent, green tinted
bottles have the next highest value. PET bottles with other
transparent tinted or opaque (non-transparent) colors have limited,
if any, recycling value and may be considered contaminants by
many PET reclaimers. Therefore, opaque PET bottles and transparent
pigments other than green are undesirable and should be avoided
until processing capacity and markets are established for them.
PP, OPP, HDPE, MDPE, LDPE or LLDPE label stock is preferred
to all other label materials. In addition, label materials should
not delaminate in the reclaimer’s wash system. Paper labels
are undesirable and should be avoided as they increase contamination
in the PET due to fiber and adhesive carry-over through the
reclamation process. Similarly, metallized labels increase contamination
and separation costs and should be avoided. In general, the
use of plastic labels with a density of less than 1.0 are preferred
for easy removal in conventional water-based density separation
systems. While PS labels are tolerated by many PET reclaimers,
they should only be used in forms (such as foam) where the PS
density is less than 1.0 and can be easily removed from the
PET in conventional separation systems. The use of PVC labels
is undesirable and should be scrupulously avoided.
Some label inks bleed color when agitated in hot water and
can discolor the PET regrind in the reclamation process, diminishing
or eliminating its value for recycling. The APR and NAPCOR
have developed a testing protocol to assist label manufacturers
in evaluating whether a label ink will bleed in conventional
PET reclamation systems. Label inks must be chosen that do
not bleed color when tested under this protocol. The use of
inks that bleed should be scrupulously avoided. Label adhesives
should be water-soluble or dispersible at temperatures between
140°F and 180°F in order to be removed in conventional
washing and separation systems. If adhesives are not removed
efficiently, they may disperse on the PET regrind and embed
unwanted contaminants. The use of other adhesive types is
discouraged and should be avoided. (The APR has developed
a testing protocol for adhesive manufacturers to evaluate
the impact of adhesive products in conventional reclamation
systems.) Adhesive usage and surface area covered should be
minimized to the greatest extent possible to maximize PET
yield and avoid contamination.
Presently, all direct printing other than date coding, either
for product labeling or decoration, contaminates recycled PET
in conventional reclamation systems. The inks used in direct
printing may bleed ink or otherwise discolor the PET during
processing, or introduce incompatible contaminants. In either
case, the value of the PET for recycling is diminished or eliminated.
Some PET bottle designs require the use of layers or coatings
for specific product applications. The use of non-PET layers
and coatings are undesirable and should be avoided, unless they
are compatible with PET or are easily separable from PET in
conventional recycling systems. If coatings and layers must
be used, the content should be minimized to the greatest extent
possible to maximize PET yield, limit potential contamination,
and reduce separation costs. The use of non-PET layers and coatings
can drastically reduce the recyclability of PET bottles. (The
APR’s Champions for Change Cooperative Testing Program
invites consumer product manufacturers and plastic bottle and
bottle component manufacturers to work with APR member companies
to determine whether new modifications to a regularly recycled
plastic bottle will impact conventional recycling systems prior
to introducing the modification.)
The use of base cups is undesirable and should be avoided, as
they reduce PET yield and increase separation costs. If base
cups are used, the use of unfilled HDPE or clear PET is preferred
to all other materials. If glued on, base cup adhesives should
be water-soluble or dispersible at temperatures between 140°F
and 180°F in order to be removed in conventional washing
and separation systems. If adhesives are not removed efficiently,
they may disperse on the PET regrind and embed unwanted contaminants.
The use of other adhesive types is discouraged and should be
avoided. (The APR has developed a testing protocol for adhesive
manufacturers to evaluate the impact of adhesive products in
conventional reclamation systems.) Adhesive usage and surface
area covered should be minimized to the greatest extent possible
to maximize PET yield and avoid contamination.
The use of any other attachments is discouraged, as they reduce
base resin yield and increase separation costs. If any other
attachments to a bottle are used, they should be made from HDPE
or clear PET. If adhesives are used to affix attachments, they
should be water-soluble or dispersible at temperatures between
140°F and 180°F in order to be removed in conventional
washing and separation systems. If adhesives are not removed
efficiently, they may disperse on the PET regrind and embed
unwanted contaminants. The use of other adhesive types is discouraged
and should be avoided. (The APR has developed a testing protocol
for adhesive manufacturers to evaluate the impact of adhesive
products in conventional reclamation systems.) Adhesive usage
and surface area covered should be minimized to the greatest
extent possible to maximize PET yield and avoid contamination.
The use of non-detaching bottle components, including monomers,
that are not made from PET, must either be compatible with,
or easily separable from PET in conventional recycling systems.
(The APR’s Champions for Change Cooperative Testing Program
invites consumer product manufacturers and plastic bottle and
bottle component manufacturers to work with APR member companies
to determine whether new modifications to a regularly recycled
plastic bottle will impact conventional recycling systems prior
to introducing the modification.)
The use of post-consumer PET in bottles is encouraged, whenever
possible. |
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