The Association of Plastic Recyclers
  • PP

    PP

Innovation in plastics and packaging is necessary to maintain a healthy and competitive industry. To support innovators, the APR has developed a variety of laboratory test method documents that can be used to assess the impact of a plastic design feature or component on recycling. APR test methods combine laboratory practices and measurements developed specifically by and for plastic recyclers with standard ASTM tests. The objective of testing is to determine the impact of a design feature on the processability of a package item as well as the ability of post-consumer resin (PCR) derived from such feedstocks to meet quality specifications for end-use applications. To view APR’s test method definitions, click here.

Design Feature Recyclability Category APR Test Methods APR Recognized Commercially Available Options Additional Resources
BASE POLYMER
Postconsumer Polyolefin Content check Preferred document
APR Lifecycle Inventory
Blends of PP and other resins with unknown effects in future uses of recovered resins unknown Needs Testing
Untested blends may yield Preferred, Detrimental, or Non-Recyclable results
document
PP-CG-01
Form unknown Needs Testing
Untested forms may yield Preferred, Detrimental, or Non-Recyclable results
CG Recognition Letters
COLOR
Unpigmented (Natural) check Preferred
Opaque or Translucent check Preferred
Optical Brighteners x Detrimental
Why?
Black and Dark Colors unknown Needs Testing
Untested colors may yield Preferred, Detrimental, or Non-Recyclable results
document
SORT-S-01
SORT-B-01
document
NIR Sortation
DIMENSIONS (between 8 fluid ounces and 2 gallons)
Items up to and greater than 7.5 liters (2 gallons) in volume (no large size boundary) check Preferred
Items more 3-dimensional (round) than 2-dimensional (flat) check Preferred if
approximate CASS > 20
SORT-B-0X(under development)
Small size boundary check Preferred if
< 5 cm (2 in) in 2 dimensions
document
SORT-B-02
document
Size Sortation
CLOSURES & CLOSURE LINERS; SAFETY SEALS
Polypropylene Closures check Preferred
Closure Systems without Liners, Valves check Preferred CG Recognition Letters
EVA and TPE Liners check Preferred
Polymers with density > 1.0 that sink in water - specifically PS, silicone, nylon, acetal, thermosets check Preferred
Shrink Film Safety Sleeves that are designed to be completely removed before the package can be opened check Preferred
Polyethylene or Polypropylene tamper-evident safety sleeves check Preferred
PETG or PLA tamper-evident safety sleeves check Preferred
Polyethylene closures x Detrimental
Why?
Closure liners and safety seals that are composites of AL and paper x Detrimental
Why?
Closures containing floating silicone polymer x Detrimental
Why?
PVC Closures and Tamper-evident safety sleeves check Preferred if
completely removed before package can be opened
x Detrimental
Why?
Closures or lidding with metal components unknown Needs Testing
Untested closures or liddings may yield Preferred, Detrimental, or Non-Recyclable results
document
SORT-B-03
document
Metal Sortation
Shrink Film Safety Sleeves, all materials check Preferred if
completely removed before package can be opened
document
PP-CG-01
SPRAY DISPENSERS AND PUMPS
Polymers with density > 1.0 that sink in water, specifically PS, silicone, nylon, acetal, thermosets check Preferred document
Meets Preferred Guidance Recognition Program Resource Document for Dispensers
Polyethylene dispensers x Detrimental
Why?
Valves made of silicone (density and floatability will vary) unknown Needs Testing
Untested valves may yield Preferred, Detrimental, or Non-Recyclable results
document
PP-CG-01
Valves or springs made of metal unknown Needs Testing
Untested valves may yield Preferred, Detrimental, or Non-Recyclable results
document
SORT-B-03
BARRIER LAYERS, COATINGS, ADDITIVES
"Workhorse" additives check Preferred CG Recognition Letters
Non-PP barrier materials unknown Needs Testing
Untested barrier materials may yield Preferred, Detrimental, or Non-Recyclable results
document
SORT-S-01
CG Recognition Letters document
Squeeze Tubes
Additive concentration causing blend to sink due to density > 1.0 unknown Needs Testing
Untested additives may yield Preferred, Detrimental, or Non-Recyclable results
document
O-S-01
Degradable Additives unknown Needs Testing
Untested additives may yield Preferred, Detrimental, or Non-Recyclable results
document
O-S-03
message
APR Position Statement
LABELS & INKS
Polypropylene or polyethylene labels check Preferred document
Squeeze Tubes
in-Mold labels of a compatible polymer check Preferred
Full bottle sleeve labels designed for sorting check Preferred document
Squeeze Tubes
Paper Labels x Detrimental
Why?
Label Inks unknown Needs Testing
Untested inks may yield Preferred, Detrimental, or Non-Recyclable results
document
HDPE-S-01
PP-CG-01
Metal foil, metalized, and metallic printed labels unknown Needs Testing
Untested labels may yield Preferred, Detrimental, or Non-Recyclable results
document
SORT-B-03
SORT-S-01
Full bottle sleeve labels unknown Needs Testing
Untested labels may yield Preferred, Detrimental, or Non-Recyclable results
document
SORT-S-01
SORT-B-01
PP-CG-01
HDPE-S-01
document
Squeeze Tubes
LABEL/ADHESIVE COMBINATIONS
Metal Foil Labels that pass Metal Sorting Potential Test check Preferred if
with adhesive that releases in wash
x Detrimental if
with adhesive that does not release in wash
Why?
Polystyrene Labels check Preferred if
with adhesive that releases in wash
x Detrimental if
with adhesive that does not release in wash
Why?
PLA Labels check Preferred if
with adhesive that releases in wash
x Non-Recyclable if
with adhesive that does not release in wash
PVC Labels x Detrimental if
with adhesive that releases in wash
Why?
x Non-Recyclable if
with adhesive that does not release in wash
Label/Adhesive Combinations where adhesive release and substrate float/sink behavior are not known unknown Needs Testing
Untested label/adhesive combinations may yield Preferred, Detrimental, or Non-Recyclable results
document
O-S-01
PP-CG-01
ATTACHMENTS
Plastic Attachments with Density > 1.0 except PVC check Preferred
Paper Attachments x Detrimental
Why?
PVC Attachments x Detrimental
Why?
Polyethylene Attachments x Detrimental
Why?
RFID x Detrimental
Why?
Non-PP Attachments unknown Needs Testing
Untested attachments may yield Preferred, Detrimental, or Non-Recyclable results
document
O-S-01
Metal, Metalized, and Metal Containing Attachments unknown Needs Testing
Untested attachments may yield Preferred, Detrimental, or Non-Recyclable results
document
SORT-B-03
document
Metal Sortation
Welded attachments unknown Needs Testing
Untested attachments may yield Preferred, Detrimental, or Non-Recyclable results
document
O-S-01
PP-CG-01
“Composite Attribute Summary Score” –CASS
The CASS is an evaluation of the sorting potential of an item based on its dimensions. The guiding principle is that rigid plastic packaging articles that are more three-dimensional (round, cylindrical, square) will sort more efficiently in today’s MRFs than those which are more two-dimensional (flat). The evaluation applies a weighting factor to each dimension length, then assigns the score based on the summation of the adjusted dimensions. Depending on the CASS, an item may be classified as “Preferred”, or it may need to be tested to determine its actual sorting potential. The CASS is intended to be used with the Evaluation of 2D/3D Sorting Potential of Articlestest method which is under development
Optical Brighteners
Optical brighteners are not removed in the recycling process and can create an unacceptable fluorescence for next uses of recycled PP. It is difficult to identify material with this negative effect until extremely late in the recycling process where a great deal of added cost has been imparted into a material of low value due to the additive.
Polyethylene closures
Since polyethylene floats in water like polypropylene it is not separated in the reclaimers float-sink tank.When blended with PP it negatively affects the impact properties and can render the material brittle.Although very small amounts of PE, such as that contributed by labels, are regularly accepted by PP reclaimers, closures and dispensers comprising a larger weight percentage of the package have a greater negative affect.
Liners that are Composites of AL and Paper
These materials will contaminate wash water, will contribute to waste disposal costs, or will stick to the valuable PP and reduce quality and value of the final products.
Closures containing floating silicone polymer
This material passes through the float-sink tank along with the PP and is difficult to remove with other methods, thereby causing contamination in the final product.Sinking silicone does not experience this issue.
PVC Closures and Tamper-evident safety sleeves
PVC is relatively easy to remove in the float-sink tank since it sinks while the PP floats.However, the float-sink tank is imperfect and even a very small amount of PVC with the recycled PP renders large amounts of it unusable as the PVC degrades at lower temperatures than those at which PP is processed.
Polyethylene dispensers
Since polyethylene floats in water like polypropylene it is not separated in the reclaimers float-sink tank.When blended with PP it negatively affects the impact properties and can render the material brittle.Although very small amounts of PE, such as that contributed by labels, are regularly accepted by PP reclaimers, closures and dispensers comprising a larger weight percentage of the package have a greater negative affect.
Paper Labels
The PP reclamation process involves water and agitation.The paper that detaches from the container when subjected to these conditions becomes pulp, which does not sink intact but remains suspended in the liquid, adding load to the filtering and water treatment systems.Paper remaining adhered to the PP travels with the PP to the extruder where the material carbonizes and causes color defects. Even after melt filtering, the burned smell and discoloration remain with the recycled PP thereby negatively affecting its potential reuse.Non-pulping paper labels used with non-releasing adhesives compound the problem since the entire label enters the extruder.
Metal Foil Labels that pass Metal Sorting Potential Test
If small, not detected, or allowed to pass, these labels, when used with an adhesive that does not release in the wash, either cause the attached PP to sink where it is lost in the float-sink tank or pass into the extruder where they can blind melt filters.
Polystyrene Labels
If small, not detected, or allowed to pass, these labels, when used with an adhesive that does not release in the wash, either cause the attached PP to sink where it is lost in the float-sink tank or pass into the extruder where they can blind melt filters.
PVC Labels
When used with an adhesive that releases in the wash, these labels sink in the float-sink tank where they are removed. But because the float-sink tank is imperfect, and even a very small amount of PVC entering the extruder causes severe quality and yield problems, this material is detrimental.
Paper Attachments
The PP reclamation process involves a wash step that removes adhesives and other components.This process renders paper into a pulp which is very difficult to filter from the liquid, adding significant load to the filtering and water treatment systems.Some of the small individual paper fibers will remain with the PP and carbonize when the material is extruded, causing unacceptable quality degradation.
PVC Attachments
Because the float sink tank is imperfect and even a very small amount of PVC entering the extruder causes sever quality and yield problems, this material is detrimental. PVC degrades at PP extrusion temperatures and renders large amounts of the recycled PP unusable.
Polyethylene Attachments
When blended with PP it negatively affects stiffness and impact properties.Although very small amounts of PE, such as that contributed by labels, are regularly accepted by PP reclaimers, some attachments comprise a larger weight percentage of the package and therefore a greater negative affect.
RFID
While RFID’s are small, they may affect PP recycling in the same ways as metal labels or other attachments. The use of RFID’s is discouraged as may limit PP yield, introduce potential contamination, and increase separation and waste disposal costs.
APR Recognized Commercially Available Options
Expanded polypropylene hinged lid containers, 0.2 g/cc density
APR Recognized Commercially Available Options
Millad® NX™ 8000

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