RecyClass has released a Design Book with the goal of providing a practical guide that clarifies the definition of recyclability and highlights key considerations for designing both rigid and flexible packaging for recycling with maximum output quality as the priority. 

Defining recyclability

RecyClass begins the Design Book with a definition of recyclability. The organisation defines plastic packaging as recyclable if it meets all 4 criteria:

1. The product must be made with plastic that is collected for recycling, has market value, and/or is supported by a legislatively mandated programme.

2. The product must be sorted and aggregated into defined streams for recycling processes.

3. The product can be processed and reclaimed/recycling with commercial recycling processes.

4. The recycled plastic becomes a raw material that is used in the production of new products.

In line with the fourth requirement of the recyclability definition, RecyClass endorses the concept of circularity as defined by the Ellen MacArthur Foundation. This means that, for the organisations, plastic circularity is dependent on material circulation where packaging re-enters the economy in packaging applications for as long as possible.

Therefore, closed-loop applications – where recycled plastic packaging waste is used to produce new plastic packaging – are the benchmark for RecyClass’ Testing Protocols and Design for Recycling Guidelines. However, RecyClass does acknowledge that, in some cases, functionality requirements make it difficult to design certain packaging types for closed-loop recycling systems and suggests that design decisions should favour longer, multiple-step cascaded recycling in such scenarios.

Assessing recyclability

The RecyClass Methodology, intended to provide a scientific, fact-based approach for the assessment and certification of plastic packaging recyclability, was developed by RecyClass in collaboration with various value chain stakeholders. In its new Design Book, RecyClass says that its Methodology promotes the high standards that are pivotal to improving the quality of waste in such a way that helps to ‘close the loop’ on plastic packaging.

There are multiple evaluation steps in the RecyClass Methodology. The first step is to ensure that packaging belongs to a plastic stream and does not contain any main disqualifiers, which include a plastic content below 50%, bio- or oxo-degradable additives, and surfaces containing carbon black (which cannot be detected by common sorting technologies like Near Infra-Red (NIR) detection). The following step then requires verification that a recognised pre recycling stream exists for the packaging.

Step three of the RecyClass Methodology refers to calculating the amount of “recoverable and valuable” plastics that can be targeted within the recycling stream. RecyClass has developed a ranking system depending on available content: Class A, the highest category, requires the packaging to have over 95% recoverable and valuable content, while Class E, the lowest category, includes packaging with less than 50% recoverable and valuable content.

In the next step, RecyClass calls for an analysis of sortability based on criteria such as the label and/or sleeve used, the composition of the main body of the packaging, and whether it is mono- or multi-layer.

According to the organisation, companies should then test the sorting efficiency in an operational sorting plant following the RecyClass Sorting Protocol, which applies penalties depending on efficiency and contamination levels. RecyClass applies no penalties where efficiency of over 80% is achieved, with less than 10% contamination, while efficiency of 50-70% and over 20% contamination leads to disqualification.

After these steps, RecyClass says that companies should consider any incompatibilities via the Design for Recycling Guidelines in order to provide high-quality recycled plastic. Incompatibilities fit into two categories, according to RecyClass: removable materials and components; and non-removable materials and components.

RecyClass also includes an ‘easy to empty’ index, which requires an assessment of whether the packaging is easily accessible and emptied. This is aimed at minimising residues, such as food, which can contaminate the recycling stream, with RecyClass again applying penalties depending on performance.

The final step of the RecyClass Methodology links with compliance. RecyClass says that companies should check that the packaging complies with reach regulations, meaning that any Substances of Very High Concern (SVHCs) are not added to the packaging. The organisation relegates packaging by three classes if there is an SVHC present.

Designing for recycling

RecyClass’ Design for Recycling Guidelines offer insights into how plastic packaging can be designed and assembled to be compatible with recycling.

There are five key principles of Design for Recycling, according to RecyClass. The first of these is choosing plastics that have a recycling stream in the EU, which for rigid packaging includes HDPE, PP, PS, and PET bottles and trays, and PE and PP for flexibles.

RecyClass says that the next principle is maximising the proportion of the main polymer. Mono-materials are the favoured solution, according to the third RecyClass principle, with a combination of various plastics potentially complicating the sorting and recycling steps with a negative impact on the overall recyclability of packaging.

In addition, RecyClass advises that colours and printing on packaging are reduced, as these apparently cannot be removed during recycling and reduce the visual aspect and quality of the recyclate.

Linking with the RecyClass Methodology, the final principle refers to enabling consumers to empty the packaging entirely. RecyClass notes that large amount of product residue after normal use adds contaminants during recycling and results in extra water-treatment steps.

These general principles form the basis of the RecyClass Design for Recycling Guidelines, which is aimed at advising users on how to improve the overall technical recyclability of products when designing packaging. RecyClass claims that the Design for Recycling Guidelines have been tested to assess compatibility levels, are well known to the plastics recycling industry, and are continuously updated with new findings to align with market developments.

The Guidelines provide an overview of packaging design, with specific advice given depending on packaging polymer, packaging type (e.g., containers, tubes, flexibles, trays), and packaging colour. If a packaging component or feature is not covered by the Guidelines, RecyClass notes that this means its recyclability has yet to be evaluated and tested.

A traffic light system is offered to indicate levels of compatibility, with green indicating the preferred design features that guarantee the best technical recyclability and packaging that is suitable for closed-loop recycling systems, such as bottle-to-bottle.

Meanwhile, RecyClass says that the yellow column lists packaging features that have passed the Recyclability Evaluation Protocols under specific conditions or that are known to have a limited impact on recycling but are nonetheless compatible with recycling processes. In the red column are features that RecyClass considers as strongly downgrading or disqualifying full packaging recyclability, which can result in sorting issues, contamination of recycling streams, and degradation of materials.

As already highlighted by RecyClass, the behaviour of packaging and its component throughout the sorting and recycling processes will determine its overall recyclability. RecyClass also provides information on how packaging components could impact particular sorting and collection methods.

For example, the organisation says that users of the Guidelines should consider whether components could detach due to mechanical stress during compaction, especially as one-dimensional items smaller than 5cm are usually discarded and sent for incineration during the sieving stage. Additionally, taking into account magnetic and eddy current separation, RecyClass notes that plastic packaging containing metallic components may either be sent to the metal recycling stream, leading to a loss of material, or pollute the output material if allowed to remain in the plastic stream.

For NIR, which sorts packaging across polymer types and, for more refined streams, by colour, the Design for Recycling Guidelines says that avoiding packaging made of a combination of several material types can help to ensure the highest efficiency of detection. The organisation adds that large labels or sleeves, excessive use of printing, and certain pigments can also impact the efficiency of NIR, and thus should be carefully considered during the design process.

During the recycling process itself, RecyClass identifies the importance of assessing how labels and inks will fare during the washing step. The organisation suggests that using its Quick Test Procedure for bleeding inks and complying with the EuPIA exclusion policy can help to avoid the contamination of washing water and reduce decontamination costs.

As for extrusion, RecyClass says that certain components can degrade the quality of the output material and should be avoided during design. This is why the organisation considers bio- or oxo-degradable materials, such as PLA, PHA, and starch, to be disqualifying components, as they can promote breakages and lower recyclate quality.

Currently, the RecyClass Guidelines are available for 16 different packaging types.

The importance of Design for Recycling

RecyClass considers design to be a key part of the waste hierarchy and an important measure in effectively addressing the challenges of plastic packaging waste. The Design Book published by RecyClass is intended to be a transparent and reliable means of assessing and verifying plastic packaging recyclability. The document can apparently be consulted by industry actors and stakeholders, regardless of their technical knowledge of recyclability.

Paolo Glerean, chairman of RecyClass, explains: “Design for Recycling is a crucial, first step in ensuring that a product will be recyclable at the end of its use phase.

“It offers insights into how plastic packaging should be designed and how different components of packaging influence its compatibility with recycling. This approach leads to improved quality of recycled plastic, and thereby stimulates its uptake in new packaging applications.”

Other guidelines focused on designing for recyclability include CEFLEX’s Designing for a Circular Economy (D4ACE) guidelines, originally issued in 2020. CEFLEX has recently been awarded funding by UK Research and Innovation to expand on the guidelines, which – like the RecyClass guidance – are aimed at improving the quality of recycled materials, while giving clarity to key players across the flexible packaging value chain.

CEFLEX, like RecyClass, recommends the use of recyclable mono-materials for packaging and presents a hierarchy of preference for flexible recycling streams, which places mono-material PE and PP at the top. However, CEFLEX also acknowledges that compromises on the protective qualities of packaging to improve recycling can, in fact, have a higher environmental impact and ultimately fail to actually improve recycling rates.

With the UKRI funding, CEFLEX is looking to further develop the D4ACE guidelines by testing more flexible packaging structures with a view to enhance recyclability, especially for flexible packaging that is not yet widely sorted and mechanically recycled.

Earlier this year, the 4evergreen Alliance released the Circularity by Design guidance, with recommendations on how to design fibre-based packaging for recycling from the start of its lifecycle. 4evergreen defines the recyclability of fibre-based packaging according to established recycling processes, the viability of substituting out virgin material, and avoiding energy recovery. The organisation also identifies components that can disrupt the recycling process; like those highlighted by RecyClass for plastics, these include additives, inks, and contaminants like food left on the packaging after use.

“With the help of the recyclability evaluation protocol, we have been able to establish the technical recyclability of different materials and even consider output quality,” Ralf Mack, co-lead of the 4evergreen Exert Group on Circularity by Design, commented on the guideline. However, he acknowledges that “responsibility for improving the recycling rate of fibre-based packaging does not lie solely at the feet of packaging designers” – suggesting that holistic collaboration across the value chain is needed to facilitate circularity for a range of packaging types.