PET is ubiquitous in our daily lives, serving as a vital raw material for clothing, household goods, technical components, and particularly bottles, which represent approximately 70% of global PET usage. Its near-limitless recyclability positions it as a cornerstone of the circular economy. As we look ahead, this potential is set to expand further. According to the new EU Packaging & Packaging Waste Regulation (PPWR), PET bottles are mandated not only to be designed for recycling but also to gradually incorporate a higher percentage of recycled content. However, achieving these goals remains challenging. For instance, if labels adhere with conventional adhesives, the recycled PET can become unsuitable for food and drink packaging applications. The effective solution lies in developing adhesives that can be completely and cleanly removed during the recycling process.
The PPWR stipulates that single-use bottles must contain at least 25% recycled content by 2025, escalating to 30% for all plastic bottles by 2030. Utilizing regranulate yields multiple advantages: it conserves fossil resources such as crude oil, which would otherwise be required for new plastic production. Additionally, recycling PET consumes approximately 88% less energy compared to generating plastic from primary raw materials, thereby supporting more sustainable practices in food and drink sustainable packaging.
While over 60% of PET bottles are currently collected in Europe, industry experts predict that an additional 11 billion bottles could be diverted back into the recycling stream each year. The EU plastics strategy aims to incentivize higher collection rates for PET beverage bottles and enhance recycling infrastructures. However, effective reuse hinges on the recyclability of every component of the bottle. In particular, the labels must detach without leaving residues, a requirement often unmet in practice due to the use of non-removable adhesives.
Cloudy Outlook: When Adhesives Stick Around
At first glance, the recycling process appears straightforward: collect, clean, and recycle bottles. However, the reality is significantly more complex. In specialized recycling facilities, collected PET bottles are shredded, and the resulting flakes undergo washing in hot water baths. While lighter label remnants float away and can be skimmed off, many conventional adhesives cling stubbornly to the flakes. The standard hot caustic soda method, designed to remove label material and other contaminants, frequently leaves adhesive residues intact. Typical removal rates oscillate between 12% and 30%.
The implications of these residues are serious: they contribute to cloudiness and yellowing, undermining the optical quality of the recycled PET. More critically, when contaminated flakes compromise barrier properties, food safety is at risk, especially since PET bottles are typically thin-walled for resource efficiency. Contaminated PET flakes may no longer be fit for food and drink packaging and are often relegated to lesser applications, such as sweaters or flowerpots.
Recyclability Starts With Adhesive
Modern adhesives face stringent demands: they must ensure that PET remains in the recycling loop while also being compatible with existing labeling technologies. One promising solution is dispersible hot melt adhesives, which can almost entirely dissolve or transform into easily removable forms when treated with hot caustic soda. For instance, Henkel Adhesive Technologies’ TECHNOMELT EM 335 RE can achieve removal rates up to 98% residue-free. Specifically designed for PET labels, its dispersibility in hot caustic soda guarantees that adhesive remnants are separated from the material stream alongside the labels, thus facilitating the production of ultra-pure PET flakes suitable for new food and drink packaging.
Moreover, this solution provides additional advantages: the hot melt functions effectively for both paper and plastic labels and can be utilized in production lines processing up to 40,000 bottles per hour. Its low application temperature (110–140 °C) safeguards equipment and lowers energy consumption. With a mineral oil-free formulation and compliance with food safety regulations, it is also well-suited for sensitive applications. Practical packaging in X-tra Chubbs simplifies handling, allowing for precise adhesive dosing while minimizing packaging waste through complete film dissolution.
Value Chain in Transition: More Recycling Through Improved Material Separation
The recyclability of PET bottles is determined across the entire value chain, from preform manufacturers to beverage fillers and retailers. Each stakeholder must make informed decisions early in the process. Developing specialized raw materials, suitable labels, and tailored adhesives is crucial for ensuring bottles can be repurposed into high-quality applications like food and drink packaging at the end of their life cycle.
Dispersible adhesives play a pivotal role in this transition. They render PET bottles truly recycling-friendly, aligning with the ambitions of the newly established EU regulations. Ultimately, those striving to meet the challenging PPWR targets require solutions that not only adhere reliably but also disengage seamlessly at the appropriate time.
For further details, visit www.henkel.com