Sustainable and Recyclable

In-mold technologies used for the labeling and decoration of plastic products are a sustainable and
recyclable alternative to many other types of labels or decoration.

In-mold labels are not removed in the recycling process since they are bonded with the wall of the package. They will flow through the recycling process…and be blended with the recycled [resin]. The lack of adhesive is beneficial to recycling since it cannot affect color or other mechanical properties.

Association of Recycling Professionals (APR)


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Recyclable.

At the IMDA, Recyclable refers to the ability of a product to be recycled – to be accepted at the MRFs for processing, converted into recycled material and reused in future operations.

The label or decoration is made of the same material type as the product or container, which simplifies sorting during the recycling process and allows the entire object to be ground into recyclate.

No adhesives are used to secure the label to the product or container. Recycling facilities have indicated adhesives can “gum up” the screens in the recycling equipment when the paper label is removed from the plastic container.

Sustainable.

At the IMDA, Sustainable refers to product reuse, operational efficiencies and energy savings, reduced plant floor footprint and more – the environmental impact of manufacturing production.

IML and IMD are efficient processes, reducing the labor needed with the use of automation and robotics to place the label in the molding process and remove the product or container after the molding process is complete. This allows optimal utilization of employee labor in other areas of the facility.

There is no need for secondary decorating processes, eliminating additional equipment that requires floor space and additional energy inputs.

IML is a recommended labeling technology

The Association of Plastic Recyclers (APR) has designated IML as a “Preferred” labeling method for polypropylene (PP) and high-density polyethylene (HDPE) when labels of a compatible polymer are used because the label is bonded with the wall of the package/part. APR’s guidance also notes, “The lack of adhesive is beneficial to recycling since it cannot affect color or other mechanical properties.”

To ensure packaging is optimized for recyclability, the Association of Plastics Recyclers has published guidance for both PP and HDPE to help designers measure each aspect of the design against industry-accepted criteria to ensure that there will be no contamination or quality issues. APR’s Design Guidance also mentions the tendency of some label inks to bleed color in the reclamation process and recommends choosing label inks that do not bleed.

References

The Association of Plastics Recyclers, “PP (Polypropylene, Resin Identification Code #5),” The Association of Plastics Recyclers | PP Design Guidance (https://plasticsrecycling.org), accessed March 23, 2023.

The Association of Plastics Recyclers, “PP Design Guidance,” accessed March 20, 2023.

The Association of Plastics Recyclers, “HDPE Design Guidance,” accessed March 20, 2023.

The World Packaging Organization recommends the use of mono-materials in packaging applications and, in its design guidance, gives labeling processes such as IML a green “best case” ranking in its traffic-light rating system, saying, “If labels and sleeves are used, they should be made of the same base material as the bottle body…” IML is mentioned specifically in regard to PE and PP cups/trays and PE and PP tubes, with WPO offering the green “best case” rating.

The World Packaging Organisation noted in its design guidance that degree of print coverage is a possible detriment to ease of recyclability.

References

World Packaging Organisation, “Global Packaging Design for Recycling Guide, https://www.ecr-community.org/global-recyclable-packaging-guide/

The Flexographic Technical Association notes that in-mold technologies increase efficiency and reduce waste by making it possible for flexographic printers to work with recessed panels, inclines, asymmetrical features and applications like hot foil and fluorescent and metallic inks. The resulting benefit is the ability to create blow-molded bottles/containers of any design or shape in a fully recyclable decorating process that eliminates both liners and adhesive.

References

Flexographic Technical Association, “Niche Market No More: In-Mold Labels Strengthen Brand Recognition, Cut Waste,” https://www.flexography.org/industry-news/in-mold-label-iml-strengthen-brand-recognition-cut-waste/, accessed March 17, 2023.

RecyClass’s “Design for Recycling Guidelines” has designated IML for both PP containers and HDPE containers and tubes as “fully compatible with coloured PP recycling when the amount of ink is below 1% of the total weight of the full packaging.”

Design Guidance and Recycling Requirements

Design for recycling considers whether each packaging element, e.g., caps, labels or adhesives, is compatible with the container’s recycling streams.

RecyClass offers a guide to help designers optimize packaging for recyclability, with guidance based on the RecyClass Recyclability Evaluation Protocol. In the case of PP packaging and HDPE containers and tubes, the guide describes inmold labels as having “full compatibility” with colored PP and PE recycling if the amount of ink is < 1 wt% of the full packaging weight (except dark colors and bleeding inks). Compatibility with colored PP recycling declines when the amount of ink is ≥ 1 wt% of the full packaging weight (except bleeding inks), and compatibility with natural PP recycling is low. For HDPE containers and tubes, any other PE in-mold label receives a conditional compatibility designation (except bleeding inks). 4

References

RecyClass, “RecyClass: Impact of PP-based In-Mould-Labels (IML) Technologies on Recycling of PP Containers,” https://recyclass.eu/wp-content/uploads/2022/04/Technical-Review-In-Mould-Labels-final.pdf, accessed March 17, 2023.

RecyClass, “Design for Recyclability,” https://recyclass.eu/recyclability/design-for-recycling-guidelines/, accessed March 20, 2023.

Handbook on Decorative Technologies, https://recyclass.eu/wp-content/uploads/2022/06/Handbook-on-Decoration-Technologies-for-Rigids_v.1.1.pdf

2.9 IN-MOULD-LABELS In-mould labelling is the use of paper or plastic labels during the manufacturing of rigid PP and HDPE packaging by blow moulding, injection moulding, or thermoforming processes. The label serves as an integral part of the final product, which is then delivered as a pre-decorated item. IML is a fully automated process in which a pre-printed paper or film is inserted into a mould before the container is created. As the container is being formed, the container resin fuses into the label, thus wedging it on the sidewall of the container structure. Because IML is firmly attached to the container, it will enter the recycling process with the container. Printing methods of IML are (UV-) Offset, (UV-) Flexography, Digital Printing, Rotogravure, UV Rotary Letterpress. The vast majority of IML labels have no adhesive on the backside as the container melts into the label. In case paper IML labels for blow moulding are used, the paper label can have an adhesive on the backside. Polypropylene is commonly used as label material, with a thickness of 40-110 micrometres resulting in a monomaterial packaging. PE and paper are less used materials for IML decoration.