PREFERRED

Polyethylene mono-material flexible packaging

Pure polyethylene, bio-based or not, is compatible with flexible films collection streams and easily recycled into a variety of end use applications, including new flexible films, composite lumber, and other molded plastic products. As the supply stream includes a mixture of grades of PE, individual packages may also be comprised of various PE grades, as defined by ISO 472:2013 – HDPE, LDPE, LLDPE, MDPE, VLDPE. Special grades of PE available in the industry like plastomers, mLLDPE, ULDPE and others are also included as “Preferred”.

Based on APR company data and evaluation by the APR Film Committee, EVA copolymers designed for film extrusion are included in the “Preferred” category at any weight percent, provided the VA (vinyl acetate) levels are 5% or less of the total package weight.

One company has received Critical Guidance Recognition for a branded ionomer copolymer intended for use in film extrusion. Based on the chemical similarity of ethylene copolymer ionomers and this data, it has been demonstrated that ethylene copolymer ionomers do not affect recyclability performance when used up to 20% in PE formulations. For that reason, ethylene copolymer ionomers designed for film extrusion are also listed as “Preferred” when used below 20% in weight of the total package.

PB (polybutenes) are also typically used in small fractions on PE “easy peel” film formulations that are currently recycled in the industry with no adverse effects. For this reason, PB is accepted in the “Preferred” category up to 5% in weight.

A minimum of 90% PE and copolymers by weight of the total packaging structure is preferred for full compatibility with a PE mechanical recycling process, in order to maintain the quality and value of the final recyclate. This is the guideline threshold to be strived for, but not an absolute rule. Ethylene copolymers like the ones mentioned above or even other-than-PE materials can be listed in this category above 10% after proper recyclability testing based on the APR Critical Guidance Protocol.

Postconsumer PE content

The use of PCR PE in all packages is encouraged to the maximum amount technically and economically feasible.

DETRIMENTAL

Less than 90% PE

Structures with 80-90% PE and copolymers by weight of the total package may present technical challenges for the recycler’s yield, productivity, or final product quality. They are considered detrimental until tested and film designers should refer to the other sections of this document for more specific guidelines.

RENDERS NON-RECYCLABLE

PET, PVC, PVDC, Paper, Aluminum foil or degradable polymers

These polymers lead to the contamination of polyolefin recycling streams. They drastically reduce the quality of recycled polyolefins and they can disturb the recycling process.

PET is incompatible with polyethylene 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.

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

Paper or aluminum-foil-containing materials are not suitable for recycling within the polyolefin stream and cause problems for the recycling process.

Degradable polymers (photo, oxo, or bio): Recycled film is intended to be reused into new products. The new products are engineered to meet particular quality and durability standards given properties of typical recycled film. 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. They should not be confused with degradable additives, which are covered in another section of this document. 

REQUIRES TEST RESULTS

Less than 80% PE

Structures with less than 80% PE of the total package will likely affect the overall yield of the respective PE mechanical recycling process and could negatively impact the recycled plastic quality. For that reason, they should be tested to determine the appropriate APR recyclability category.

BENCHMARK TEST

DEFINITIVE TEST

Blends, coextrusion or lamination of PE and other resins designed to enhance properties in the intended first use with unknown residual effects in future uses of the recovered resin

Non-PE 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 PE or remain solid and are filtered from the melted product.

Testing must show that unfilterable layers have no adverse effect on the recycled PE in future uses. These include:
• EVOH
• PVOH
• Nylon (PA)
• Polypropylene (PP)

The above materials may be acceptable at small weight percentages of the total film but only testing can determine this. 

Several compatibilizers are available on the market that may, if used correctly, allow a non-compatible material to blend with PE without negative effects. This has been successfully demonstrated for specifically formulated films including EVOH and nylon. Providers of these solutions must present evidence of effective compatibilization by testing the specific formulation of the film and pursuing critical guidance or benchmark validation from APR. One company has received Critical Guidance Recognition for a two-layer PE based film including an EVOH coextruded film with tie layers and a compatibilizer, and scavenging additive.

Any other material combination not mentioned above, with or without compatibilizers, at any level (%) needs further testing to qualify for recycling with the polyolefin stream. A few examples include:
• COC
• PS
• EPCs
• PB (above 5%)
• Engineering thermoplastics (PBT’s, PC’s, etc.)
• Crosslinked polymer layers (chemically, EBeam or UV)
• Elastomeric materials
• Nonwoven (Tyvek® and others)
• Other fiber-based materials

One company has received Critical Guidance Recognition for a multi-layer PE film including COC content.

Some PE additional copolymer categories also require testing, for example:
• Acid copolymers (EAA & EMAA)
• Ester copolymers (EMA, EEA, EBA)
• Ionomers (above 20%)

Tie resins/layers are typically grafted-polyethylene copolymers used to bond incompatible layers on coextruded or laminated films. They are not required to undergo testing independently, but only to validate recyclability of the incompatible-to-PE materials listed above.

BENCHMARK TEST

DEFINITIVE TEST

PREFERRED

Unpigmented (Natural) PE 

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. 

White, buff, or lightly colored film

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 blend well with little effect. 

DETRIMENTAL

Dark colors

While dark colors are not considered Preferred, they are nonetheless readily accepted by recyclers even if technically Detrimental (features that present known technical challenges for the MRF or recycler’s yield, productivity or final product quality, but are grudgingly tolerated and accepted by the majority of MRFs and recyclers). Darker colored PCR manufactured from darker color feedstock may be used for inner layers, and there is evidence that the marketplace is becoming more accepting of darker colored material if it can help them meet recycled content goals.

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. Dark colors have a great effect on a lot of material. Since the standard material is a light blend and dark colors are relatively rare, the reclaimer normally hand selects dark colors and processes them separately. In some cases, the dark colors are discarded. 

RENDERS NON-RECYCLABLE

None specified

REQUIRES TEST RESULTS

Metallic pigments

Pigments designed for a visual metallic appearance on plastic films are not removed in the recycling process and are melted and blended with the PE.  This may cause material discoloring.  In many cases a metallic film will 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. There is also some evidence that metallic inclusions can be captured in ultra-fine laser filters and potentially cause equipment problems.

Test Methods (in order):

SCREENING TEST

BENCHMARK TEST

DEFINITIVE TEST

Pigments concentration where density approaches 0.996

Many pigments like TiO2 (titanium dioxide) and others are very dense and when blended with the polymer increase the overall density of the film. When their weight percentage reaches the point that the film density is greater than 0.996 g/cc, the film sinks in water rather than floats. Density is an important property and float-sink tanks are critical separation tools used by reclaimers. Therefore, a sinking material will be considered waste by a film reclaimer and any PE in the blend will be lost.

SCREENING TEST

PREFERRED

Polyethylene flexible seals, closures, or dispensers

Since polyethylene is the same polymer as the package body, closures made of it will be captured and processed with the PE film. The utilization of such should be limited to less than 10 wt% of the total package. This increases the reclaimers yield and reduces possible waste.

DETRIMENTAL

See “Requires Test Results" section

RENDERS NON-RECYCLABLE

Metal and metal containing closures, dispensers or attachments
Metal parts are extremely problematic in two areas. First, they alarm metal detectors that are employed at the beginning of the recycling process to protect machinery. When this occurs, the entire package containing the offending part is discarded and landfilled. Secondly, if they happen to pass through the process into the extruder, they can damage the extruder or quickly clog a melt filter causing a pressure upset which automatically shuts down the process for safety.

REQUIRES TEST RESULTS

Non-PE flexible or rigid seals, closures, dispensers, and other attachments

These components enter the film recycling process along with the film they are attached to. They enter the extrusion stage of the process with the base material where they are either melted and blended with the PE or remain solid and are filtered from the melted product. PP- based attachments fall in this category and must be tested for recyclability. Testing must show that the material is removed from the PE stream or has no adverse effect on the recycled PE in future uses.

BENCHMARK TEST

DEFINITIVE TEST

Polyethylene Rigid Attachments

It is known that some additional features such as large spouts/closures relative to the overall weight of the
flexible packaging item can cause items to be sorted with a rigid packaging stream. However, it is not possible
to give general advice on this, so it is suggested testing is undertaken if in any doubt.

Rigid injection-molded attachments are typically produced with low-viscosity (high Melt Flow Index) resins that may impact recycling into films. These attachments to film packaging should be minimized. If rigid attachments are used, they should be polyethylene to be compatible with recycling. One company has received Critical Guidance Recognition for a multi-layer PE film package that includes a rigid PE spout. 

BENCHMARK TEST

DEFINITIVE TEST

PREFERRED

Workhorse additives historically used without issue

Most PE film contains some form of additives. The “workhorse" additives commonly used have not been shown to cause significant issues with the recycling process or further uses of the recycled PE. Commonly acceptable workhorse additives include:

• Thermal stabilizers - These additives typically enhance the further processing of the polymer and are therefore preferred for recycling.
• UV stabilizers – These additives typically enhance the further processing of the polymer and are therefore preferred for recycling
• Nucleating agents
• Antistatic agents
• Antifog agents
• Lubricants and processing aids
• Slip and anti-blocking agents
• Fillers – note that many fillers are dense, so particular attention should be paid to the overall blend density
• Pigments
• Chemical blowing agents
• Tackifiers

Additive usage should be minimized to maintain the best performance of recycled material for future uses.

SiOx and AlOx barrier coatings

Vacuum-deposited coatings like SiOx and AlOx are accepted as Preferred only when applied directly to PE 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. These layers represent a lower percent in weight when compared to additives normally present in PE films like SiO2 or similar antiblocking agents, listed as Preferred above.

DETRIMENTAL

None specified

RENDERS NON-RECYCLABLE

PVDC coatings

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

Additive concentration where density is greater than 1.0

Many of the additives and fillers used with PE are very dense and when blended with the polymer increase the overall density of the blend. When their weight percentage reaches the point that the blend density is greater than 1.00 g/cc, the blend sinks in water rather than floats. Density is an important property and float-sink tanks are critical separation tools used by film reclaimers. Therefore, a sinking material will be considered waste by a film reclaimer and any PE in the blend will be lost. 

SCREENING TEST

REQUIRES TEST RESULTS

Metalized layers

Metalized layers are extremely thin coatings of metal deposited on the film as a vapor.  They should not be confused with actual metal layers addressed as “foil” in this document.  Metalized layers are not removed in the recycling process and are melted and blended with the PE.  This may cause material discoloring.  In some cases, a metalized film will 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.

Vapor deposited metal layers are frequently applied to oriented polypropylene (OPP) or polyester (OPET) films for flexible packaging laminations that may end up in the PE recycling stream. Since PP and PET have higher melting points than PE, negative effects of these metallized laminates may occur in the extrusion and melt filtration processes. However, when deposited into recyclable substrates like PE, oriented or not, mono (OPE) or biax (BOPE), the layer of aluminum metal is at the nanometric level, which should not present any significant risk to recyclers on the melt filtration step.

Test methods (in order):

BENCHMARK TEST

BENCHMARK TEST

DEFINITIVE TEST

Additive concentration where density approaches 0.996

Many of the additives and fillers used with PE film are very dense and when blended with the polymer increase the overall density of the film. When their weight percentage reaches the point that the film density approaches 0.996 g/cc, the film may sink in water rather than float and it should be tested. Density is an important property and float-sink tanks are critical separation tools used by reclaimers. Therefore, a sinking material will be considered waste by a film reclaimer and any PE in the blend will be lost.

SCREENING TEST

Degradable additives (photo, oxo, or bio)

Recycled film is intended to be reused into new products. The new products are engineered to meet particular quality and durability standards given properties of typical recycled film. Additives designed to degrade the polymer and diminish the life of the material in the primary use may also shorten the useful life of the product made from the recycled film, possibly compromising quality and durability, if not removed during the recycling process.

APR Position Paper

Other additives and coatings

A growing number of innovative materials are being used as additives and coatings in PE film packaging. These materials must be tested to determine their impact on PE film recycling processes and the PCR produced: unconventional additives, layers, plasma coatings, liquid PVOH, EVOH, curable barrier coatings (chemically, EBeam or UV), and other barrier coatings not listed .

Vacuum-deposited coatings like AlOx and SiOx including additional layers of primers or other wet coatings need to be tested for recyclability.

BENCHMARK TEST

DEFINITIVE TEST

The guidance considers the direct application of inks to the film package as more impactful than inks printed on a label substrate, as direct printing fulfills a decorative function whereas a label conveys more limited information. However, label technologies and printing must also conform to guidance.

PREFERRED

Polyethylene labels with tested inks and adhesives

Labels may represent a significant fraction in weight on flexible packaging, being more critical on recyclability when compared to rigid packaging. Ideally, no label is preferable, but if a flexible film needs labelling, a PE-based substrate is preferred over paper or any other material.

Polyolefin labels that have been tested and found to be compatible with PE recycling systems

APR offers various testing protocols and options for recognition to companies striving to design and commercialize Preferred labels and printing systems for PE films. Test results demonstrating recycling compatibility can determine material classification. One company has received Critical Guidance Recognition for a compatible olefin based label system. 

DETRIMENTAL

Printed labels with untested inks

Inks applied to the label must be minimized to prevent the same potential adverse effects listed in the “Direct Printing Inks, Primers, Coatings and Laminating Adhesives” section.

Untested label adhesives

The amount of adhesive should also 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.

Paper labels

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. This significantly limits its reuse.

See "Requires Test Results" section

RENDERS NON-RECYCLABLE

Metal foil labels

These labels should not be confused with metalized film. Metal foil labels are extremely problematic in two areas. First, they alarm metal detectors that are employed at the beginning of the recycling process to protect machinery. When this occurs, the entire package containing the offending part is discarded and landfilled. Secondly, if they 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.

REQUIRES TEST RESULTS

Even though they are currently recycled commercially, there is no solid evidence available for a complete evaluation of the impact of the packaging components above on the recycling process and the recycled material. Test results or equivalent evidence need to be developed, based on which these guidelines will need to be confirmed or updated.

Label inks applied to Preferred label materials

The guidance considers the direct application of inks to the film package as more impactful than inks printed on a label substrate, as direct printing fulfills a decorative function whereas a label conveys more limited information. Labels typically feature smaller amounts of printing and limited colors. However, the impact of printed labels must still be evaluated for recycling compatibility.

Certain levels of ink components dispersed in the final polymer are thought to be responsible for the grey-green color of recycled PE pellets. While this is a noticeable quality impact, markets exist for such colored PCR pellet when the correct inks are used and there is no impact on physical or chemical properties of the PCR.

The amount of printing should be limited since heavy levels of ink 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.

Heavily printed labels using dark color inks can be problematic since the dark color affects a large amount of polymer, limiting its potential for reuse.

Some label inks bleed color in the reclamation process, discoloring the PE in contact with them and possibly diminishing its value for recycling. Since most recycled PE is colored, the impact of bleeding inks may not be significant; however, since the end use is not known beforehand, label inks should be chosen that do not bleed color when recycled.

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.

SCREENING TEST

BENCHMARK TEST

DEFINITIVE TEST

Labels with metallic inks

Inks designed for metallic appearance are not always removed in the recycling process and are melted and blended with the PE. This may cause material discoloring. In many cases a metallic ink will 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 print and a solid metal part, so the entire package is normally discarded rather than accept the risk.

SCREENING TEST

BENCHMARK TEST

DEFINITIVE TEST

Label adhesives

Testing must show the adhesive is compatible with PE in the recycling process. The typical film PE recycling process conditions are not designed to remove and/or separate a label from its package, adhesive “debonding” is not a requirement. However, due to potential downstream filtration issues from the label adhesive, minimal adhesive coverage is encouraged and must show compatibility within the PE recycling process.

The APR is developing a screening PP/HDPE Adhesive Test to classify adhesive as compatible with PE whether reclaimed in a wet or dry process. Companies that are considering label adhesives and are unsure of their compatibility with recycling should ask their suppliers to provide APR test results.

Non-wash friendly, incompatible adhesive is detrimental to recycling.

BENCHMARK TEST

DEFINITIVE TEST

The guidance considers the direct application of inks to the film package as more impactful than inks printed on a label substrate, as direct printing fulfills a decorative function whereas a label conveys more limited information.

PREFERRED

Unprinted and non-laminated PE

Unprinted and non-laminated 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.

Tested inks, primers, coatings and laminating adhesives that disperse in the final polymer without having an impact on quality

APR offers various testing protocols and options for recognition to companies striving to design and commercialize Preferred printing systems, inks, coatings and laminating adhesives for PE films. Test results demonstrating recycling compatibility can determine material classification. One company has received Critical Guidance Recognition for a two-part, water-based, acrylic/urethane hybrid lamination
adhesive along with a two-part, water-based, acrylic/urethane hybrid surface coating system. One company has received Critical Guidance Recognition for a two-part, solventless polyurethane lamination adhesive used at nominal 2% loading on undecorated polyethylene films.

DETRIMENTAL

Direct printing, primers & overprint lacquers and coatings, glossy or matte

Certain levels of ink components dispersed in the final polymer are thought to be responsible for the grey-green color of recycled PE pellets. As long as there is no impact on physical or chemical properties of the PCR, and the correct inks are used, markets exist for such colored PCR pellet.

The amount of printing should be limited since heavy levels of certain 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.

Some direct print inks bleed color in the reclamation process, discoloring the PE in contact with them and possibly diminishing its value for recycling. Since most recycled PE is colored, the impact of bleeding inks may not be significant; however, since the end use is not known beforehand, inks should be chosen that do not bleed color when recycled.

Heavily printed film of dark colors can be problematic since the dark color affects a large amount of polymer, limiting its potential for reuse. (see discussion in PE Film Color section)

Testing of inks, primers, coatings and laminating adhesives is encouraged to identify innovative technologies that can be preferred for recycling.

Laminating adhesives, 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. Heavy adhesive levels also potentially impact the physical properties of the end market PCR or product.

See "Requires Test Results section"

RENDERS NON-RECYCLABLE

High levels of inks, primers, coatings and laminating adhesives that cause significant degradation of physical and mechanical properties of the end market PCR or product.

See “Requires Test Results” Section

REQUIRES TEST RESULTS

Even though they are currently recycled commercially, there is currently no solid evidence available for a complete understanding of the impact of the packaging components above on the recycling process and the recycled material. Test results or equivalent evidence need to be developed, based on which these guidelines will need to be confirmed or updated.

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.

BENCHMARK TEST

DEFINITIVE TEST

Metallic inks

Inks designed for metallic appearance are not always removed in the recycling process and are melted and blended with the PE. This may cause material discoloring. In many cases a metallic ink will 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 print and a solid metal part, so the entire package is normally discarded rather than accept the risk.

SCREENING TEST

BENCHMARK TEST

DEFINITIVE TEST