Label selection should be considered carefully to find the solution most compatible with the recycling process that also provides the necessary performance characteristics. At a minimum, labels must be designed so NIR sorting machinery can identify the bottle polymer with the label attached, and labels should use adhesives that release from the bottle. Removing adhesives is a significant component to the cost of recycling so the packages using the lowest quantity of appropriate adhesive are the most compatible.
Polymer labels with a density < 1.0 that float in water, specifically polypropylene or polyethylene
These materials float in water so they are separated from the PVC in the float-sink tank with the closures. Since they are the same general polymer as most of the closures they do not contaminate or devalue this stream. Care should be taken to ensure that any modifiers to the label material do not increase its density above 0.95. Note that these are not removed in the combined recycling process but, instead become a contaminate. Minimizing label size is advantageous to both processes.
The PVC reclamation process involves a hot caustic wash that removes glue and other label components to the levels required to render the RPVC usable. Paper, when subjected to these conditions, becomes pulp which is very difficult to filter from the liquid, thereby adding significant load to the filtering and water treatment systems. Individual paper fibers making up pulp are very small and difficult to remove so some travel with the PVC. Paper fibers remaining in the RPVC carbonize when the material is heated and re-melted, causing quality degradation and a burnt smell to the polymer. Non-pulping paper labels that resist the caustic wash process sink in the float-sink tank, thereby causing RPVC contamination. These, although removed when the polymer is melt filtered, carbonize causing the same effect.
Also see "Requires Test Results" Section
PET and PETG
Both materials are extremely difficult to remove in the recycling process due to their similarity in density to PVC which causes them to sink in the float/sink tank along with the PVC. Both cause severe quality degradation in the final recycled PVC stream even in very small amounts.
REQUIRES TEST RESULTS
Laminated label substrate
Labels that break into small, very thin pieces of material are more difficult to manage in the recycling process because they behave erratically in a float-sink tank. Therefore, labels that stay intact are preferred. Carry-over of delaminated labels into the RPVC can result in contamination.
*Under Development - Definitive Test: New Delamination Test
Full bottle sleeve labels
Full bottle sleeve labels cover a large amount of the bottle surface with a polymer that is not the same as the bottle body. Because of this, a sleeve label designed without considering recycling may cause a false reading on an automatic sorter and consequently direct a PVC bottle to another material stream where it is lost to the process. Furthermore, some sleeve label materials cannot be removed in the recycling process and contaminate the RPVC produced. Sleeve labels that have been found compliant with the APR test protocols should be selected.
Metal foil, metalized and metallic printed labels
Sortation testing for metal components will result in either a Detrimental or a Renders Non-Recyclable ruling. Metal components cannot be Preferred at this time. Sorting equipment in the recycling process is designed to detect and eliminate metal from PVC. Even very thin metallized labels may be identified as metal by the sorting equipment and cause the entire bottle to be rejected as waste, thereby creating yield loss. If not detected, they pass through the process with the PVC and cause contamination issues in the final product.
Label structures that sink in water because of the choice of substrate, ink, decoration, coatings, and top layer
The reclaimers rely on float-sink systems to separate non-PVC materials. Label components that sink with the PVC end up in the RPVC stream as contaminants. No test methods currently exist for PVC. However, PET Package Component Sink/Float Evaluation (PET-S-05) may be adapted substituting PVC for PET.
Pressure sensitive labels and adhesives
Pressure sensitive labels generally require complete adhesive coverage which is greater than other typical label methods. This raises the importance of the compatibility of the type of adhesive with the recycling process. Adhesives resistant to washing in the recycling process allow labels to remain on the container and become contaminants in the final product. Adhesives that have been found compliant with the APR test protocols should be selected.
Screening Test: TBD
PS inherently sinks in water due to its density and so it therefore travels with the PVC in the recyclers’ float-sink systems. However, Expanded PS (EPS) may float and in this case, it may be less of a problem to the recycler.
No test methods currently exist for PVC. However, PET Package Component Sink/Float Evaluation (PET-S-05) may be adapted substituting PVC for PET.
Direct printing other than date coding
Historically, inks used in direct printing tend to bleed or otherwise discolor the polymer during the recycling process or introduce incompatible contaminants. In either case, the value of the recycled polymer is diminished. Some inks used in direct printing do not cause these problems. The specific ink must be tested to determine its effect.
No test methods currently exist for PVC. However, HDPE Bleeding Label Test (HDPE-S-01) may be adapted substituting PVC for HDPE.
Adhesives that wash off cleanly from PVC and remain adhered to the label are preferred. Label adhesive that is not removed from PVC, or which re-deposits on the PVC during the wash step is a source of contamination and discoloration when PVC is recycled.
The recycling process is designed to remove reasonably expected contamination from the surface of the container to a degree necessary to render the polymer economically reusable in further applications. In practice, some adhesives are resistant to this process so are detrimental to recycling. In extreme cases, an adhesive and label cannot be separated from the PVC and may render a package not recyclable.
Screening Tests: TBD
Some label inks bleed color in the reclamation process, discoloring the polymer in contact with them and significantly diminishing its value for recycling. Label inks must be chosen that do not bleed color when tested under this protocol.
Screening Tests: TBD