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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 their general
compatibility with the base resin (PP) or their removal efficiency
in conventional water-based separation systems that separate
plastics by density. These attachments may include closures,
closure liners, base cups, inserts, labels, pour spouts, handles,
sleeves, safety seals, coatings and layers. PP has a density
less than 1.0 and will float in these systems. For efficient
separation and removal in conventional sink/float separation
systems, attachments should be made from materials with a
density greater than 1.0 or be otherwise compatible with PP
in the reclamation process. Materials with a density greater
than 1.0 will sink in these systems and can be easily separated
from the PP. (Density
range of key plastic materials.) It should be noted that
the use of PVC attachments is undesirable in conventional
recycling systems and should be avoided.
Plastic closures made from HDPE, LDPE or PP are preferred to
all others. Closure systems that contain no liners and leave
no residual rings or attachments when removed from the bottle
are also preferred. The use of closures that are unpigmented
or the same color as the bottle is desirable. The use of PVC
for closures or closure liners is undesirable and should be
avoided. The use of metal closures is undesirable and should
be avoided as they are more difficult and more costly to remove
in conventional reclamation systems compared to preferred closure
systems (HDPE, LDPE or PP).
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. Shrink sleeves
are preferred when sleeves are necessary. The use of PVC sleeves
or safety seals is undesirable and should be avoided.
Unpigmented PP bottles have the highest value and the widest
variety of end-use applications. Therefore, the use of unpigmented
PP bottles is preferred to pigmented bottles.
PP, OPP, HDPE, MDPE, LDPE, LLDPE, or PS label stock is preferred
to all other label materials. Metallized labels increase contamination
and separation costs and should be avoided. The use of PVC labels
is undesirable and should be avoided.
Inks must be chosen that do not bleed color when agitated in
hot water as they can discolor the PP regrind during the reclamation
process diminishing or eliminating its value for recycling.
The use of inks that bleed should be scrupulously avoided. (The
APR has developed a testing protocol to assist label manufacturers
in evaluating whether a label ink will bleed in conventional
PP reclamation systems.) 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 PP 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 PP yield and avoid contamination.
Presently, all direct printing other than date coding, either
for product labeling or decoration, contaminates recycled PP
in conventional reclamation systems. The inks used in direct
printing may bleed ink or otherwise discolor the PP during processing,
or introduce incompatible contaminants. In either case, the
value of the PP for recycling is diminished or eliminated.
Some PP bottle designs require the use of layers for specific
product applications. The use of non-PP layers is undesirable
and should be avoided, unless they are compatible with or easily
separable from PP in conventional recycling systems. Current
PP recycling systems can tolerate the use of EVOH layers. If
layers must be used, their content should be minimized to the
greatest extent possible to maximize PP yield and reduce potential
contamination and separation costs. (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 other attachments is discouraged, as they reduce
base resin yield and increase separation costs. Other attachments
may include handles, inserts and pour spouts, in addition to
others that might be developed. If attachments are added to
a bottle, they should be made from 1) materials with a density
greater than 1.0 — with the exception of PVC, which is
undesirable and should be avoided — that will easily separate
from PP in conventional separation systems, or 2) compatible
materials such as HDPE, LDPE or preferably unpigmented PP. The
use of HDPE or LDPE attachments, if necessary, should be limited
to less than 5 percent of the total bottle weight. Higher percentages
can contaminate the PP for many recycling applications, as these
materials are difficult to separate from PP in conventional
systems. If pour spouts are added to a bottle they should be
designed to leave no product residue and allow for complete
removal of product contents when the bottle is empty. If adhesives
are used to affix attachments, they should be water-soluble
or dispersible at temperatures between 140oF and 180oF in order
to be removed in conventional washing and separation systems.
If adhesives are not removed efficiently, they may disperse
on the PP 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
PP yield and avoid contamination.
The use of post-consumer HDPE in bottles is encouraged, whenever
possible. |
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