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5
PP Flexible (Polypropylene Flexible)

Summary
  • As of September 2024, PP flexible film collection systems are limited in North America to Canada, so this material does not currently meet the collection accessibility criteria established in “APR’s definition of recyclable” or by the Federal Trade Commission’s Green Guides. Where PP flexible film recycling exists or is developing, the APR recommends the following guidelines.
  • Common PP flexible packaging formats include pouches, bar wrap, pillow pouches, and heat stable pouches
  • PP flexible films can be single or multi-layered, using both PP homopolymer and PP copolymers
  • PP flexible packaging is most commonly used to protect fast moving consumer goods products, especially where heat stability is required
Last updated on October 23, 2024 View the change log

Base resin is defined as the polymer makeup of the primary body of the package being assessed.

PP Flex Mono-Material

>90% (by weight) PP flexible mono-material per ISO19069

PP flexible mono-material includes PP copolymers including PP random copolymers, heterophasic copolymers and PP terpolymers, PP oriented and non-oriented and PP plastomers.  The use of PCR PP Flexible material in all packages is encouraged to the maximum amount technically and economically feasible.

80-90% (by weight) PP flexible mono-material per ISO19069

Structures with 80-90% PP and copolymers by weight of the total package may present technical challenges for the recycler’s yield, productivity, or final product quality.

< 50% (by weight) PP flexible mono-material per ISO19069

>50% but < 80% (by weight) PP flexible mono-material per ISO19069

Structures with less than 80% PP flexible material of the total package will likely affect the overall yield of the respective PP mechanical recycling process and could negatively impact the recycled plastic quality. For that reason they should be tested to determine if they are Detrimental or Non-Recyclable.

Test Protocols 

 

Coming Soon

Blends, coextrusion or lamination of PP and other resins

Requires Testing

Non-PP layers or blend components at any level require testing to determine the appropriate APR recyclability category. Since these layers are not removed in the film recycling process, they enter the extrusion stage of the process with the base material where they are either melted and blended with the PP flexible material or remain solid and are filtered from the melted product. Testing must show that unfilterable layers have no adverse effect on the recycled PP flexible material in future uses

Test Protocols 

 

Coming Soon

Contains Aluminum

Renders Package Non-Recyclable

Aluminum foil can be detected early in the recycling process by metal detectors designed to protect machinery from catastrophic damage. Metal detectors are unable to differentiate between a aluminum foil and a solid metal part, so the entire package is normally discarded rather than accept the risk. If the aluminum foil passes through metal detection, it can be damaging to the extrusion equipment or can quickly clog a melt filter causing a pressure upset which automatically shuts down the process for safety.

Contains Degradable Polymers

Renders Package Non-Recyclable

Polymers designed to degrade by definition diminish the life of the material in the primary use. If not removed in the recycling process, these polymers also shorten the useful life of the product made from the recycled film, possibly compromising quality and durability. Degradable polymers include PLAs, PHAs, PHBs, PHVs, PBS, cellulose acetate, starch-based polymers and others.

Contains Paper

Renders Package Non-Recyclable

Pulp from paper becomes a water filtration and contamination problem if they are processed through a wet recycling process. Individual paper fibers are very difficult to remove and attach themselves to the film creating specks and irregularities in the products made from recycled film. Furthermore, in either a wet or dry process they degrade in the extruder creating an undesirable burnt smell that cannot be removed from the recycled plastic which limits its end use.

Contains PET

Renders Package Non-Recyclable

PET is incompatible with polypropylene and copolymers from the chemical and rheological standpoints. It melts at significantly higher temperatures and it is known to cause film defects (“unmelts”) that compromise film quality.

Contains PVC or PVDC

Renders Package Non-Recyclable

PVC and PVDC layers degrade at low temperatures rendering large portions of the recycled PP flexible material unusable.

Adding colorant to packaging can impact NIR sortation and color, which both impact the disposition and value of the final recyclate.

Unpigmented (Natural)

APR Design Preferred

Natural material has the highest value as a recycled stream since it has the widest variety of end-use applications. It is the most cost-effective to process through the recycling system.

Colors with L value > 40 or NIR Reflectance >10%

APR Design Preferred

It is not common for film to be sorted by color in the recycling process. Therefore, the resulting recycled material is a blend of all the colors present. Light colors typically blend well with little effect to the overall color.

Resources
  • RES-SORT-01  Near Infrared (NIR) Sorting in the Plastics Recycling Process

Colors with L value < 40 or NIR Reflectance ≤ 10%

Requires Testing

L values ≤ 40 or an average NIR reflectance ≤ to 10% have a high probability of not being recognized by NIR correctly and the packaging will either be sent to the wrong plastic resin stream creating contamination or be sent to a waste stream and not recycled.  SORT-EE-01 is a screening test used early on in packaging design to obtain a preliminary evaluation of NIR sortation potential prior to performing more robust testing using SORT-S-01.

Test Protocols 
  • SORT-EE-01  Early Evaluation of the Near Infrared (NIR) Sorting Potential of a Whole Plastic Article
  • SORT-S-01  Evaluation of the Near Infrared (NIR) Sorting Potential of a Whole Plastic Article
Resources
  • RES-SORT-01  Near Infrared (NIR) Sorting in the Plastics Recycling Process

Pigmented where density > 0.996 g/­cm3

Requires Testing

Many pigments used with PP film are dense and when blended with the polymer increase the overall density of the film. Density is an important property and float-sink tanks are critical separation tools used by film reclaimers. When their weight percentage reaches the point that the film density approaches 0.996 g/cm3, the film should be tested as it may sink in water and in turn become waste at a film reclaimer.

Test Protocols 

 

Coming Soon

Metallic Pigment

Requires Testing

Metallic film can be detected early in the recycling process by metal detectors designed to protect machinery from catastrophic damage. Metal detectors are unable to differentiate between a metallic film and a solid metal part, so the entire package is normally discarded rather than accept the risk.  Testing using Sort S-03 can determine this impact.  If the metallic film passes through metal detection, it is then melted and blended with the PP film and can cause material discoloration. There is also some evidence that metallic inclusions can be captured in ultra-fine laser filters and potentially cause equipment problems.  Testing using critical guidance can determine this impact.

Test Protocols 

 

Coming Soon – Critical Guidance Test Protocols

  • SORT-S-03  Evaluation of Sorting Potential for Plastic Articles Utilizing Metal, Metalized, or Metallic Printed Components

Colors that are not NIR Detectable

Renders Package Non-Recyclable

PP flexible material that cannot be recognized by NIR due to its non-detectable color will be sent to a waste stream and not recycled.

Resources
  • RES-SORT-01  Near Infrared (NIR) Sorting in the Plastics Recycling Process

Made with PP Flexible Materials

APR Design Preferred

Since polypropylene flexible is the same polymer as the package body, closures, seals and dispensers made of it will be captured and processed with the PP film.

Made with PE Flexible Materials

APR Preferred if < 10% of total package weight

Made with PP Rigid Material

Requires Testing

Large closures/spouts relative to the overall weight of the flexible packaging can cause items to be sorted to a rigid packaging stream. If sorted to the PP flexible stream, rigid injection-molded attachments are typically produced with low-viscosity (high Melt Flow Rate) resins that may impact recycling into films. Testing should be performed to determine the overall impact on on the PP flexible recycling stream.

Test Protocols 

 

Coming Soon

Made with Non-PP Flexible or Rigid Materials

Closures enter the film recycling process along with the film they are attached to. When entering the extrusion process they are either melted and blended with the PP film or remain solid and are filtered from the melted product. In order to be considered Preferred, testing must show that the material is either removed from the PP stream or has no adverse effect on the recycled PP films end use.

Test Protocols 

 

Coming Soon

Made with or Contains Metal Materials

Renders Package Non-Recyclable

Metal materials can alarm metal detectors that are employed at the beginning of the recycling process to protect machinery. If this occurs, the entire package containing the offending part is discarded and landfilled. In addition, if metal materials happen to pass through the process into the extruder, they can quickly clog a melt filter causing a pressure upset which automatically shuts down the process for safety.

Barriers, Coatings, Additives and Layers are materials added to to the base resin to improve performance such as enhancing the appearance or processability of a package.

Workhorse Additives

APR Design Preferred

Most PP film contains some form of additives but usage should be minimized to maintain the best performance of recycled material for future uses. The following “workhorse” additives commonly used have not been shown to cause significant issues with the PP film recycling process or end use: Thermal stabilizers, UV stabilizers, Nucleating agents, Antistatic Agents, Antifog Agents, Lubricants and Processing Aids, Slip and Anti-blocking Agents, Fillers, Pigments and Tackifiers.

Additives with Blend Density < 0.97g/­cm3

APR Design Preferred

SiOx and AlOx Barrier Coatings

APR Design Preferred

Vacuum-deposited coatings like SiOx and AlOx are considered Preferred only when applied directly to PP films without the use of additional wet coatings or primers. These materials are completely inert, non-detectable by any metal detection method used in the recycling industry and deposited as nanometric thin layers on film surfaces, with negligible effect on film density.

EVOH

Ethylene Vinyl Alcohol copolymer (EVOH) is a common layer material used to increase the barrier properties of PP packaging. It is not separable in the recycling process and therefore will become part of the recycled PP. Maleated polypropylene (PP-g-MAH) tie layers are commonly used in combination with EVOH to improve the adhesion between PP and EVOH and have been shown to improve compatibility during the recycling process.

EVOH ≤ 6.0 wt% + PP-g-MAH tie layers with MAH > 0.1 wt% and EVOH:tie layers ratio ≤ 2

EVOH > 6.0 wt% + PP-g-MAH tie layers with MAH > 0.1 wt% and EVOH:tie layers ratio ≤ 2

EVOH > 1% with any other tie layer

Metalized Barrier Layers

Metallized content where surface area ≤ Preferred Surface Area per RES-SORT-03b

Metalized content that is untested or does not pass SORT-S-03

Without further testing, metal content with surface areas above the Preferred Surface Area in RES-SORT-03b are categorized as Non-Recyclable due to a higher probability of being removed by the metal detector during sortation. When packaging is rejected by a metal detector, the package is sent to a waste stream and not recycled.

Metallized content where surface area > Preferred Surface Area per RES-SORT-03b

Metalized film layers can be detected early in the recycling process by metal detectors designed to protect machinery from catastrophic damage. Metal detectors may not be able to differentiate between a metalized film and a solid metal part, so the entire package may be discarded rather than accept the risk. Therefore, metalized content above the Preferred Surface Area specified in RES-SORT-03b needs to be tested using SORT-S-03 to verify they are under the spherical equivalent thresholds.  If metalized film passes SORT-S-03, it should then be tested using critical guidance to ensure the metalized content does not negatively impact the final recyclate.

Test Protocols 

 

Coming Soon – Critical Guidance Testing Protocols

  • SORT-S-03  Evaluation of Sorting Potential for Plastic Articles Utilizing Metal, Metalized, or Metallic Printed Components
Resources

Cavitation Foaming Agents

Requires Testing

Test Protocols 

 

Coming Soon

Additives with Blend Density 0.97 g/­cm3 - 1.0 g/­cm3

Requires Testing

Many of the additives and fillers used with PP film are very dense and when blended with the polymer increase the overall density of the film. Density is an important property and float-sink tanks are critical separation tools used by film reclaimers. When their weight percentage reaches the point that the film density is greater than 0.97 g/cm3, the film should be tested as it may sink in water and in turn become waste (and yield loss) at a film reclaimer.

Test Protocols 

 

Coming Soon

PVDC Barrier Coatings

Renders Package Non-Recyclable

PVDC degrades at low temperatures rendering large portions of the recycled PP unusable.

Additives with Blend Density > 1.0 g/­cm3

Renders Package Non-Recyclable

Many of the additives and fillers used with PP are very dense and when blended with the polymer increase the overall density of the blend. Density is an important property and float-sink tanks are critical separation tools used by film reclaimers. When their weight percentage reaches the point that the blend density is greater than 1.00 g/cm3, the blend sinks in water rather than floats and becomes waste (and yield loss) at a film reclaimer.

Degradable Additives

Renders Package Non-Recyclable

See APR Position Paper

Other Additives/­Barriers

Requires Testing

A growing number of innovative materials are being used as additives and coatings in PP film packaging. These materials must be tested to determine their impact on PP film recycling processes and the PCR produced

Test Protocols 

 

Coming Soon

Labels can interfere with automated sorting as well as impact the quality and quantity of the final recyclate.  It is important to consider all aspects of a label such as Surface Area, Substrate, Metal Decoration, Inks and Adhesives when selecting a label.

Surface area coverage is defined as the area of the label divided by the area of the side wall and shoulder of the container. The area of the neck ring, threaded finish and base are not included in the area calculation. The surface coverage area of a label can impact whether or not a package can successfully sorted by NIR and color optical sorters. Label surface area coverage, in conjunction with with substrate, metal decoration, inks and adhesives must be considered when selecting a label.

The label substrate, in conjunction with surface coverage area, metal decoration, inks, and adhesives, must must be considered when selecting a label.

Polymer Film Labels

Made with Polypropylene Materials

Since polypropylene is the same polymer as the package body, labels made of it can be captured and processed with the PP film.

Made with Polyolefin Materials

Polyolefin labels may be compatible with the PP film stream, but require testing to determine their impact on PP film recycling processes and the PCR produced

Test Protocols 

 

Coming Soon

Paper Labels

Detrimental to Recycling

Paper labels pulp and become a water filtration and contamination problem if they are processed through a wet recycling process. Individual paper fibers are very difficult to remove and attach themselves to the film creating specks and irregularities in the products made from recycled film. Furthermore, in either a wet or dry process they degrade in the extruder creating an undesirable burnt smell that cannot be removed from the recycled plastic which limits its end use.

Metal Foil Labels

Renders Package Non-Recyclable

Metal foil labels can alarm metal detectors that are employed at the beginning of the recycling process to protect machinery. If this occurs, the entire package containing the offending part is discarded and landfilled. In addition, if metal foil labels happen to pass through the process into the extruder, they can quickly clog a melt filter causing a pressure upset which automatically shuts down the process for safety.

Resources

Metal decoration on labels includes vapor deposited metal films, metal foils, or inks with metallic pigments. Metal decoration content, in conjunction with surface coverage area, substrate, inks and adhesives, must be considered when selecting a label.

Metal Decoration

Label with metal decoration where surface area ≤ Preferred Surface Area per RES-SORT-03b

Labels with metal decoration that are untested or do not pass SORT-S-03

Without further testing, metal decoration with surface areas above the Preferred Surface Area in RES-SORT-03b are categorized as Non-Recyclable due to a higher probability of being removed by the metal detector during sortation. When packaging is rejected by a metal detector, the package is sent to a waste stream and not recycled.

Labels with metal decoration where surface area > Preferred Surface Area per RES-SORT-03b

Metal decoration on labels above the Preferred Surface Area specified in RES-SORT-03b need to be tested using SORT-S-03 to verify they are under the spherical equivalent thresholds.

Test Protocols 
  • SORT-S-03  Evaluation of Sorting Potential for Plastic Articles Utilizing Metal, Metalized, or Metallic Printed Components
Resources

The label inks, in conjunction with surface coverage area, substrate, metal decoration, and adhesives, must be considered when selecting a label.

Direct Print Inks

Any amount of Nitrocellulose Binders

Untested Non-Metallic Inks

Non-Metallic Inks

Non metallic inks require testing to determine their impacts on the recycled PP films.  Use critical guidance testing to determine impacts.

 

For inks that do contain metal see label guidance for Metal Decoration.

Test Protocols 

 

Coming Soon – Critical Guidance Testing Protocols

Label Inks

Any amount of Nitrocellulose Binders

Untested Non-Metallic Inks

Non-Metallic Inks

Non metallic inks require testing to determine their impacts on the recycled PP films.  Critical guidance testing can determine impacts.

 

For inks that do contain metal see label guidance for Metal Decoration.

Test Protocols 

 

Coming Soon – Critical Guidance Test Protocols

The label adhesive, in conjunction with surface coverage area, substrate, metal decoration, and inks, must be considered when selecting a label.

Label Adhesive

Untested Label Adhesive

Tested Label Adhesive

The amount of adhesive should be limited since heavy levels can degrade and volatize in the extruder and may cause gels and specks in the final product even if most recyclers use vented extruders. Large amounts of adhesives can overwhelm the capacity of these extruders to remove the volatile components.

Test Protocols 

 

Coming Soon

Wet Chemistry

The use of wet chemistry materials should be minimized as it may limit the potential reuse of recycled films by negatively impacting film appearance (gels, specks) and mechanical properties.

Any amount of Nitrocellulose Binders

Tested Direct Print Primer, Overprint Lacquers and Coatings

Certain levels of ink components dispersed in the final polymer are thought to be responsible for the grey-green color of recycled PP pellets. The amount of printing should be limited since heavy levels of ink components may degrade and volatize in the extruder, causing gels and specks in the final product even with vented extruders. Large amounts of printing can overwhelm the capacity of these extruders to remove the volatile components.

Untested Direct Print Primer, Overprint Lacquers and Coatings

Tested Laminating or Cold Seal Adhesives

The amount of adhesive should be limited since heavy levels can degrade and volatize in the extruder and may cause gels and specks in the final product even if most recyclers use vented extruders. Large amounts of adhesives can overwhelm the capacity of these extruders to remove the volatile components.

Untested Laminating or Cold Seal Adhesives

Curable inks, coatings and adhesives

Chemically, EBeam or UV curable inks, primers and adhesives are thermoset in nature, not melting with the thermoplastic components of a flexible film, thus acting as a contaminant in the recycling process. Depending on the amount used, they may limit the potential reuse of recycled films by negatively impacting film appearance (gels, specks) and mechanical properties.

Test Protocols 

 

Coming Soon