Polypropylene or polyethylene tamper evident safety sleeves are preferred.
PP safety sleeves are the same polymer as the final product, and PE at the very small levels expected from safety sleeve residue has a very minimal negative impact. Therefore, these attachments that remain with the PP throughout the recycling process increase yield and have minimal negative quality impact for the reclaimer.
PETG tamper evident safety sleeves are preferred.
PETG sinks in the float sink tank where it is removed from the PP. Unlike PVC, small amounts of PETG entering the extrusion process with the PP are not catastrophic since PETG can be melt filtered.
PVC tamper evident safety seals are detrimental to recycling.
PVC sinks in the float-sink tank where the majority of it is removed from the PP. 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.
Non-PP attachments require testing to determine the appropriate APR recyclability category.
Testing must show that these attachments are not adhesively bonded to the package and are made from materials that sink in water so they readily separate from the package when ground and put through a float-sink separation. If adhesives are used to affix attachments, their selection should consider the adhesive criteria within this document.
Test Protocol: PP Benchmark Test
Metal, metalized, and metal-containing attachments require testing to determine the appropriate APR recyclability category.
Metal or metal-containing attachments may cause NIR sorters in MRFs to misidentify a PP container as metal and direct it to a metal stream, from which it is then discarded. Sorting equipment in the reclaiming process is designed to detect and eliminate metal from PP in order to protect cutting machinery. Large items, or items adhesively bonded to the PP, can damage the machinery and render the entire package non-recyclable. If small, not detected, or allowed to pass, metals, when used with wash friendly or no adhesive quickly sink in the float sink tank where they are removed from the PP.
Benchmark Test: Evaluation of Sorting Potential for Plastic Articles Utilizing Metal, Metalized or Metallic Printed Components
Plastic attachments with a density > 1.00 except for PVC are preferred.
These items sink in the sink-float tank where they are removed from the PP and small residual amounts do not severely affect the final product since many of them are melt filtered. PVC is detrimental as discussed elsewhere in this document.
Welded attachments require testing to determine the appropriate APR recyclability category.
A certain amount of a welded attachment cannot be separated from the PP in the recycling process. These attachments may cause recycled PP contamination and yield loss issues in both cases: when the ground section containing both polymers sinks and carries the PP with it, or when the ground section floats and carries an incompatible material with the PP into the extrusion process. Testing must show that the blend is of a density less than 1.0 so that it floats along with the PP in the float-sink tank, and that it is compatible with PP in the extrusion process.
Polyethylene attachments are detrimental to recycling.
Since polyethylene floats in water like polypropylene it is not separated in the reclaimers float-sink tank. 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’s (radio frequency identification devices) on packages, labels or closures are detrimental to recycling.
RFID’s are printed on silver metal, which may create costly waste disposal issues. While RFID’s are small, they may effect 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 cost.
PLA attachments are preferred.
As discussed in the sections on labels and closures, PLA sinks in the float-sink tank and can be therefore removed from the PP. Unlike PVC, small amounts of PLA entering the extrusion process are not catastrophic
PVC attachments are detrimental to recycling.
PVC sinks in the float sink tank where the majority of it is removed from the PP. 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.