PP Rigid Packaging with Printed In-Mould Labels tested by RecyClass
New findings for decorative technologies25 Apr 2022
RecyClass carried out an analysis to verify the compatibility of PP-based, printed In-Mould Labels (IMLs) technologies with recycling of PP containers. The results demonstrate that this decorative technology is compatible with coloured, rigid PP recycling stream under the condition that the total weight of the inks does not exceed 1% of the weight of the container. At the same time, the analysis has shown that IML have a low compatibility with the natural stream.
In-Mould Labels, unlike other labels, are a decorative technology which is directly moulded in the container and does not require the adhesive to be put on the container. Therefore, it is non-removable and consequently is not separated in a recycling process. IML decoration can be used in numerous industries, including food, beverage, cosmetics, healthcare, and is typically applied on rigid containers such as tubs and buckets.
RecyClass Recyclability Evaluation Protocol for PP Containers was used as the basis for performing the laboratory testing which were carried by independent laboratories - the Institut für Kunststofftechnologie und -recycling (IKTR) and Proplast. Four samples were tested: transparent and printed IML applied to a natural PP container; two white, printed IMLs on white PP containers as well as white, printed IML on a coloured PP packaging. The obtained pellets were reprocessed using injection moulding and the analysis demonstrated that while the IML itself does not strongly impact the quality of the recyclate, the printing ink used for such applications led to the presence of unmelted particles of inks in the recyclate. Additionally, recycling of the natural container with the transparent printed IML led to coloured pellets due to the presence of the inks as IMLs cannot be separated during the recycling process.
Following these new findings, the RecyClass Design for Recycling Guidelines were updated accordingly for both coloured and natural PP and the update was equally extended to HDPE containers & tubes. Consequently, and according to the results, PP-based In-Mould Label technology is considered fully compatible with coloured PP recycling when the amount of ink is below 1% of the total weight of the full packaging, while it is limited compatible when the amount of ink is above 1%. On the other hand, IML technology was classified as having low compatibility with the natural PP containers recycling due to its non-separability.
The RecyClass evaluation involved comprehensive testing with a selection of samples that are representative of containers currently available on the market in terms of the colours, shapes and applied printing to enable the extension of the findings to all types of IMLs.
Today, the industry is actively working on innovative decorative packaging technologies that are not disruptive to the recycling processes. By evaluating the new technologies and providing advice on how to design them, RecyClass helps the industry to ensure recyclability of products on the market and guides the industry towards genuinely circular plastic solutions.
 Excluding dark colours and bleeding inks
RecyClass is a comprehensive cross-industry initiative that works to advance plastic packaging recyclability and to establish a harmonized approach towards recycled content calculation and its traceability in Europe. Activities within RecyClass include the development of Recyclability Evaluation Protocols and scientific testing methods for innovative materials which serve as the base for the Design for Recycling Guidelines and the Recycling Online Tool. RecyClass offers Recyclability Certifications for plastic packaging and Recycled Content Traceability Certification for plastic products.