Although 44% of post-consumer packaging trash and 66% of all products marketed in the EU are packaged in flexible materials[i], the majority of EU homes do not currently have access to flexible plastic recycling at the curb, and only 6% of flexible plastics are recycled.
Flexible plastics are difficult to recycle for a variety of reasons, not the least of which is the obvious lack of infrastructure. Other problems include the quality of the material that is collected and whether it is suitable for recycling, as this can depend on the inks and coatings used during production. There are currently a number of agencies recommending that companies stop using inks on plastics in order to increase their recyclability. This leaves very little room for product coding and labelling, and the approach is both unneeded and premature. According to Olivier Morel, Product Development Manager at Domino Printing Sciences, manufacturers should make sure that their product labelling promotes recycling efforts rather than interferes with them by selecting the appropriate ink.
Rates of Recycling for Flexible Plastic Containers The Ellen MacArthur Foundation reports in the Global Commitment Progress Report for 2022 that the majority of business signatories will “likely not be met” in their goal to fully implement reusable, recyclable, or compostable packaging by 2025, with the use of flexible plastic packaging being identified as a major contributing factor. While flexible plastic (plastic bags, plastic film, and food wrapping, for example) is difficult to recycle, it is a very effective packaging material, thus the answer to this problem is anything but straightforward. Its extremely low weight reduces transportation-related carbon emissions while offering a host of advantages such as quality assurance, product protection, and preservation. In addition, the production of flexible plastic uses 60% less energy than that of traditional packaging materials like paper and card, and it generates 50% and 70% less air and water pollution, respectively. Furthermore, the energy required to recycle plastics is only 10% that required to recycle paper. Reducing the amount of flexible plastic used in food packaging would therefore eventually raise additional sustainability-related difficulties. However, because flexible plastic recycling and collecting are not done on a large scale, we are stuck with flexible plastic end-of-life issues. As a result, we as an industry need to work even harder to increase flexible plastics’ potential for recycling. A primary obstacle to the extensive recycling of flexible packaging is the often poorer material equality compared to larger polymers. One aspect of this problem may be the inks used on flexible packaging; adding extra materials to plastic packaging might degrade its quality and make it less recyclable. That being said, the inks used on flexible packaging—whether for product data coding and marking or full printing on flexible films and labels—have an important role to play, therefore it’s critical to make sure the solutions are appropriate for recycling.
Inks’ Function in Product Packaging Product labelling is crucial for allowing producers of food and drink to convey important information to retailers, consumers, and the entire global food supply chain. Product labels are also a useful tool for informing customers about proper handling of packaging after its useful life has ended, from a waste and recycling standpoint. This could include facts about the contents of the packaging and whether or not it can be recycled; instructions on how to properly dispose of the packaging (e.g., recycle at home, in-store, or at a recycling facility); or further information encoded in 2D codes, including links to the closest recycling facility. Regulations and mandatory product labels are being implemented more frequently to assist consumers in properly disposing of packaging. More nations are probably going to follow the lead established by France’s ‘Tri-man’ emblem, Italy’s Legislative Decree 116/2020, and the UK’s Department for Environment, Food & Rural Affairs (DEFRA) Recycle Now mandate. Additionally, more labelling initiatives are being implemented with the goal of enhancing packaging trash collection and sorting. Electronic Watermarks For instance, HolyGrail 2.0 seeks to employ digital watermarking to improve packaging quality rates and sorting in the EU. The idea is for a high-resolution camera to identify and decode the digital watermark, which is an otherwise undetectable code, once the packaging has been admitted to a waste sorting facility. Then, the packaging will be sorted into appropriate recycling streams. Therefore, how can manufacturers be sure that the inks used to comply with all of these coding specifications will enhance rather than impair a packing material’s ability to be recycled?
Developing Recyclable Inks There aren’t many laws that outline specifications or limitations of inks on recyclable packaging. It is probably only a matter of time until they are implemented, though, with the present emphasis on increasing recycling rates—especially in light of the growing number of independent, non-aligned guideline documents available for brands. As an illustration, consider the Ellen MacArthur Pioneer Project Barrier: “Recyclability Guidelines for Plastic-Based Flexible Barrier Packaging,” the D4ACE-Guidelines from CEFLEX, and the RecyClass tool from Plastic Recyclers Europe. However, there are a few best practises for choosing ink that companies can adhere to in order to maximise the recycling potential of their packaging and stay ahead of any upcoming requirements.
The 5% Rule states that the amount of ink printed on packaging must not exceed 5% of the package’s total weight. Even if more is printed in order to print more information, as in high-resolution 2D codes or on-pack recycling labels, this doesn’t pose a difficulty with contemporary coding and marking methods. Using digital inkjet printing technologies instead of analogue printing techniques will assist guarantee that the amount of ink printed for full product printing stays below the 5% threshold. Ingredients for inks should be chosen so as to minimise the possibility of technical issues during recycling: Avoid using ink elements that could thermally disintegrate and produce hazardous or problematic products, especially when it comes to plastics, when the temperature of reprocessing materials is between 200°C and 270°C. Some ink elements can produce gases that degrade the quality of the recycled material, caustic materials that might harm recycling equipment, and other chemicals that can discolour. Additionally, inks have to be “non-bleeding,” meaning they shouldn’t leave any obvious stains on the recycling flakes or washing fluids after they’ve dried. Inks should either have a chemical makeup similar to the package substrate or be readily removed from it. Inks that stick to recycled materials can change their colour and transparency, decreasing their value. It might consequently be necessary to de-ink the material in order to eliminate any remaining colourants and restore it to its original form before producing high-quality recycle from flexible packaging. De-inking analogue printing, in which two thin layers of the packaging substrate are layered with an ink layer for the entire decoration, can be quite challenging. Using digital printing methods, surface printing—placing the ink on top of the substrate—increases the possibility that the ink can be removed, raising the value of the recycled material.
EuPIA Guidelines Should be Followed by Inks:It is not always possible to remove all pollutants from the original packing material when recycling plastics, and this can lead to an accumulation of contaminants in the recycling stream over time. Because of this, it’s critical to make sure that inks printed onto plastics that can be recycled are free of substances that, if recycled in higher concentrations, could be harmful to human health. In order to prevent using dangerous or hazardous materials, all inks used on recyclable packaging should be created and produced in accordance with the European Printing Inks Association’s (EuPIA) Exclusion Policy.
Conclusion
Considering the numerous advantages of flexible packaging and its widespread use in the global food and beverage markets, it seems unlikely that there will be a reduction in the utilization of flexible plastics in the foreseeable future. Nonetheless, it is undeniable that a collective effort is required to enhance the proportion of flexible plastics that undergo recycling. While enhancing recycling infrastructure is one vital aspect, it is equally important to simplify and make recycling information more accessible to consumers. Additionally, harnessing technology to enhance the sorting and processing capabilities within recycling facilities is crucial. Inks play a pivotal role in this communication, making it imperative to ensure that inks are designed with recyclability in mind. This is where collaborating with a reputable ink supplier with expertise in coding, marking, and digital printing can greatly benefit brands as they work towards achieving global objectives to boost the recyclability of flexible plastic packaging.
