EXPANDED RANGE OF MATERIALS – Part 1, Recycled materials
Fresh thinking is needed when it comes to materials, and a change of mindset is required in terms of design. When we talk about the use of alternative materials, it is important that we also take into account current development progress, availability, potential, wider circumstances, and approvals for these materials. After all, these factors are just as varied as the possibilities these materials offer as feedstock for sustainable packaging solutions. We provide an overview of the current situation.
The idea: Recycled plastic waste is processed and used to produce new packaging. While this concept sounds straightforward, its implementation is quite complex.
Depending on the type of waste, there are different ways in which plastics can be usefully recycled. Two basic approaches are mechanical and chemical recycling. Mechanical recycling consumes less energy, giving it a better carbon footprint – however, it can only be used to process unmixed plastics. To be commercially efficient, a sufficient quantity of these plastics must be available. Pyrolysis-based chemical recycling, on the other hand, can be used to process both mixed and soiled recyclables. For the use of mechanically recycled plastics in Europe, a positive opinion from the EFSA (European Food Safety Authority) is an essential requirement when it comes to bringing the material into contact with food. With a few specific exceptions, this has only been granted for r-PET to date.
Chemically recycled materials and renewable materials are currently used in accordance with the mass balance approach. This involves plastic packaging producers purchasing a certificate for a material stream, which ensures they contribute toward the use of chemically recycled or renewable material. This certificate guarantees the material’s traceability along the entire supply chain. An initial group of Greiner Packaging locations are already ISCC PLUS certified. Greiner Packaging views a combination of chemical and mechanical recycling as the most likely option for the future. But other recycling methods, such as enzymatic and physical recycling, could also occupy a greater share of the market.
Status quo: r-materials
Polyethylene terephthalate (PET) can be recycled both mechanically and chemically. Both processes yield food-grade recycled material. This recycled material’s high degree of purity stems from the high-quality PET bottle recycling streams, which are processed in the form of flakes or pellets. In general, packaging can consist of up to 100 percent mechanically recycled r-PET, but only up to 50 percent chemically recycled r-PET, as there are currently no granules made of 100 percent chemically recycled material.
Greiner Packaging sees great potential in r-PET and set up its own in-house r-PET business unit in early 2021. Work is currently underway, for example, on initial solutions for r-PET dairy product packaging that can also withstand high-temperature sterilization (HTS) before filling. In addition, we are currently building a standard range of r-PET cups in various sizes.
Mechanically recycled high-density polyethylene (PE), i.e., HDPE, has an FDA recycle number. However, with a few exceptions, it has not yet received a positive EFSA opinion, so is largely unable to be used for food contact applications. Currently, the packaging produced from mechanically recycled HDPE is primarily used for a few cosmetic and cleaning products. Chemical recycling of PE is expected to become a more credible option in the coming years.
Packaging solutions for cosmetic products consisting of up to 100 percent r-HDPE.
In Europe alone, around 10 million metric tons of polypropylene (PP) are processed each year, of which approximately 4 million tons are used for consumer packaging. PP therefore offers great potential when it comes to developing sustainable material streams. There are strenuous efforts underway to secure a positive EFSA opinion for mechanically recycled r-PP, but the use of this recycled material is currently restricted to the nonfood sector. In the European Union, the availability of chemically recycled polypropylene will increase in the years ahead, and the material is already available in limited quantities for use in food sector packaging.
Polystyrene (PS) offers significant potential for mechanical recycling, as sorting and recycling processes are able to achieve a high degree of purity and PS exhibits lower migration levels than polyolefins. In addition, PS is very easy to sort, and the small number of different qualities in the virgin material has a positive effect on its usefulness as a feedstock. A dossier based on the results of several challenge tests has already been submitted for an EFSA opinion. As with the establishment of recycling streams, this will be critical to the successful use of mechanically recycled PS in the future. In the context of chemical recycling, producers’ food-grade compliance is confirmed using the mass balance approach.