This is how the Recycling of PET Trays Succeeds

The IK Industrievereinigung Kunststoffverpackungen (Industrial Association for Plastic Packaging) has founded a panel of experts on the subject of PET trays. The aim is to promote the recycling of PET trays for foodstuffs.

Nowhere is is something touched and groped at in the supermarket as much as in the fruit and vegetable ails. This refers to unpackaged fruits and vegetables that customers check for firmness and freshness. Delicate fruits and vegetables can suffer from this “inspection.” Those who prefer to buy packaged fresh produce reach for PET trays.

However, PET trays still have to catch up in terms of recycling. “Problem recognized, danger averted: this is precisely what the PET trays working group at the IK Industrievereinigung Kunststoffverpackungen (association of the plastic packaging industry) is working hard to achieve,” explains the IK Industrievereinigung Kunststoffverpackungen.

Crystal-clear and virtually airtight: the high transparency of PET trays gives a clear view of the quality and appearance of the goods. And the oxygen barrier ensures that sensitive products such as meat or fish are protected without using additional composites. This helps the circular economy – and much less food is wasted, explains the IK Industrievereinigung Kunststoffverpackungen.

The only problem is that recycling PET trays is complex – even though they are made from PET, which is in principle a recyclable material. PET is a thermoplastic from the polyester family produced by polycondensation. “The material is ideally suited for recycling because, unlike other plastics, it can be recycled an almost unlimited number of times. The PET bottle sets an example. Here, however, we are dealing with a separate cycle, which means, firstly, that the material is in a very clean condition and, secondly, that the sorting, washing, and reprocessing processes have been designed for the bottles. Unfortunately, it is not as simple with PET trays,” says Sebastian Kremer Chief Sales and Marketing Officer at and chairman of the working group.

Different types of PET trays

What are PET trays? Basically, they can be divided into so-called monolayer trays and multilayer trays. PET monolayer trays are used for fruit, vegetables and meat and are made of pure PET. Multilayer PET trays, in which sausage and cheese are packed, are different. They consist of a stable tray and a flexible lidding film. To ensure that the food packaged in them has an even longer shelf life, other polymers are used in addition to PET: EVOH, for example, forms a secure barrier against oxygen, and polyethylene – PE for short – protects against water vapor and forms a sealing layer. Multilayers account for 60 percent of the market.

EVOH stands for ethylene-vinyl alcohol copolymer and is used as a plastic, for example, to apply barrier layers. This avoids oxygen ingress and thus quality losses. They are sorted into the following groups: on the one hand into mixed PET with different mixing ratios of transparent PET bottles and other dimensionally stable articles made of PET, for example trays. The mixed PET fraction is then usually re-sorted so that the proportion of bottles can be further increased. In this process, however, the PET trays mainly accumulate as rejects.

The second group consists mainly of PET trays – they make up a minimum share of 75 percent in this fraction. PET trays are already recycled in small quantities. However, they are no longer used to make trays but, for example, fibers for the textile industry. In addition, there are applications such as toilet rim block holders that are made from PET trays. “For food contact, unfortunately, there are currently no applications that I am aware of. However, this is one of the key issues the working group is currently working on,” Kremer said.

To make progress on recycling PET trays, all players in the value chain need to roll up their sleeves: processors should use foreign materials in and on the tray sparingly so that the material is as recyclable as possible. The recycling companies need to sort out the shells in a targeted manner and think along with the washing and reprocessing of the PET shell material from the outset – and invest here as well. The distributors are also in demand. They have to provide other components that are ideally also made of PET. Last but not least, it is also in the hands of retailers to continue promoting PET.

After all, economic recycling is only possible if there is enough material in circulation, says the IK Industrievereinigung Kunststoffverpackungen. Looking at Europe, where significantly larger quantities of PET are in circulation than in Germany, it is also worthwhile to focus more on PET for a closed recycling loop.

From tray to tray

Therefore the PET tray working group’s goal is to continue working on the topic of “tray-2-tray recycling.” This is because the clear trays put on an outstanding performance in terms of hygiene and protective function, especially when used paired with food.

In order to further develop tray-to-tray recycling, the working group has conducted two successful large-scale trials. The results confirm that PET trays are recyclable in principle in the dual systems. It is just that legal requirements prevent them from scoring again as packaging for food in their next life.

Another result: recyclates from PET multilayer applications can also be recycled in a tray for the non-food sector. The tests also looked at the contamination of the recyclates and the thermoformed films or trays made from them. The results are positive: it can be assumed that this recyclate could also be used once more for food packaging. The “Circutray” funding project will take a statistical look at these values.

Recycling share to grow

The aim is that PET tray recyclates in the food sector will soon be able to gradually replace PET bottle recyclates from the deposit system in the production of new trays – and thus further strengthen PET recycling overall. There are already PET recyclates in which PET trays have contributed a small part of the material.

The Industrievereinigung Kunststoffverpackungen is also a partner of a “PACKBOX” event during FACHPACK. On the second day of the trade show, September 29, 2021, from 2 to 3 p.m., the PACKBOX topic will be “Plastics – Challenge or Solution?”.

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