PREFERRED

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

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

Fillers, pigments or additives with densities > 1.0 g/cm³ where density of blend with base resin is ≤ 0.97 g/cm³

Density is an important property and float-sink tanks are critical separation tools used by reclaimers. Many fillers, pigments and additives used with PE have higher densities and when incorporated into PE can increase the density of resulting PE blend causing it to sink in the float-sink tank. When a PE item sinks during reclamation, the item is lost as waste reducing yield, increasing cost, and thus will be categorized as non-recyclable. The density of an item can be calculated or measured via ASTM D792, ASTM D1505 or ISO 1183-1.

Workhorse additives that meet the PE blend density of ≤ 0.97 g/cm³

Most HDPE in a package 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 HDPE. 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
• Lubricants
• Fillers – note that many fillers are dense, so particular attention should be paid to the overall blend density
• Pigments
• Impact modifiers
• Chemical blowing agents

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

Click below for commercially available Barriers, Coatings, Additives and Fillers that have achieved APR Design for Recyclability Recognition

APR Design® for Recyclability Recognitions

DETRIMENTAL

Optical brighteners

Optical brighteners are not removed in the recycling process and can create an unacceptable fluorescence for next uses of recycled HDPE. 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.

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

RENDERS NON -RECYCLABLEL

EVOH > 1% with any other tie layers

Fillers, pigments or additives with densities > 1.0 g/cm³ where density of blend with base resin is > 1.0 g/cm³ or < 51 wt% of the PE blend floats in water per screening test.

SCREENING TEST

REQUIRES TEST RESULTS

Fillers, pigments or additives with densities > 1.0 g/cm³ where density of blend with base resin is > 0.97 g/cm³ and < 1.0 g/cm³

SCREENING TEST

Workhorse additives where PE blend density is > 0.97 g/cm³

SCREENING TEST

Non-HDPE barrier technologies other than EVOH

Testing must show that layers and coatings will either separate and be removed from the HDPE in the recycling process or have no adverse effects on the recycled HDPE in future uses. When used, their content should be minimized to the greatest extent possible. Some layers and coatings have been found compatible with HDPE or are easily separated in conventional recycling systems. Companies that are considering such barrier technologies and are unsure of their compatibility with recycling should ask their suppliers to provide APR test results Critical Guidance recognition letters.

The following barrier technologies require testing to determine an appropriate recyclable category:
• Cyclic olefin copolymers (COC)*
• Cyclic olefin polymers (COP)
• Fluorination*
• Nanocellulose
• Nanoclay
• Oxide coatings
• Polyamide (6, 66, 66/6, and including modified)
• Polyvinyl alcohol (PVOH)*
• Scavengers
• Etc.

SCREENING TEST

DEFINITIVE TEST

Degradable additives

See APR Position Paper on Degradable Additives

APR Position Paper