Petcore Europe Thermoforms Working Group shares advances in PET thermoform recycling

According to Petcore Europe, Brussels, the market for polyethylene terephthalate (PET) thermoforms in Europe is growing. Currently, PET demand for the total market for thermoforms in the European Union, Switzerland and Norway is estimated to be 1 million to 1.1 million tons.

In this context, Petcore Europe has started its Thermoforms Working Group to increase and improve the recycling of PET trays. Sept. 19, 2017, the group organized a public workshop to give the complete value chain an update on the activities and progress that has been made in PET thermoform recycling. After an introduction and market overview, the workshop featured sessions on Design-for-Recycling PET Thermoforms, Collection, Sorting & Recycling and Potential Applications and Trial Outcomes.

A market estimation conducted by the Thermoforms Working Group and presented during the workshop shows that PET is the preferred solution for monolayer, laminated (i.e., PET/polyethylene [PE] for topweb sealing) and high gas-barrier (i.e., PET/PE/ethylene vinyl alcohol [EVOH] for modified atmosphere packaging) trays, while polystyrene (PS) and polypropylene (PP) are alternatives for open trays and clamshells. North European countries tend to have more mono-PET thermoforms than laminated and high gas-barrier PET ones, while it is the opposite for South Europe; however, mono-PET is growing. Based on the market analysis, the following split applies: mono-PET, 30 to 50 percent, 400 kilotons; laminated PET,       25 to 50 percent, 300 kilotons; barrier PET, 25 to 35 percent, 300 kilotons.

PET thermoforms are the largest end-market for postconsumer recycled PET and has reached higher numbers than the PET bottle-to-bottle and fibers end markets, the group says. In 2016, a total of 490 kilotons of rPET were recycled into new thermoforms, which means an average recycle content in PET thermoforms of more than 45 percent.

The Petcore Europe Thermoforms Working Group is developing design for recycling guidelines for PET thermoforms. The presentations during this session emphasized two main challenges to be addressed:

• Labels are often too big and their glues are not suitable for easy removal in recycling plants. During the workshop a specific presentation demonstrated the potential improvement in recyclability given by new combinations of glue/labels on PET trays.
• Soaker pads that are affixed with glues that are not suitable for easy removal in recycling plants. These pads could be avoided by using a different design.

In terms of collection and sorting, a large test in France has shown that recycling of monolayer PET trays together with bottles can work under certain conditions. The sorting requires software and devices that can distinguish between mono- and multilayer packaging. The recycling process creates fines when the process is using high-friction coefficient in washing/drying steps. Another approach is to sort all PET trays from bottles, and then sort monolayer from multilayer thermoforms and develop outlets for the sorted fractions. Dedicated recycling lines for PET thermoforms are under development, the workgroup says.

The most obvious market for rPET coming from thermoforms is to use them for the manufacture of new thermoforms. Several studies have shown that washing, extrusion and solid stating result in quality material for colored applications. Retailers can increase the amount of deep colored trays for vegetables and fruits and are invited to work with packaging producers on this solution. The material is suitable to be used for agricultural trays.

Several tests also have shown that the use of PET thermoforms granulate can be used for monofilaments because the mechanical properties are very close to virgin PET, according to the workgroup. PET compounds for pellets and automotive applications are the next target, and several connections within the industry have been established.

The workshop furthermore the economics of a recycling stream of pure PET trays to produce material for compounding for injection molding applications, and the outcome looks quite promising, Petcore Europe says.

Chemical recycling is a promising technology for future recycling of “difficult to recycle” PET streams. Several startup companies are in the stage of scaling up their technologies, and tests have shown that recycling of PET/PE and PET multilayer trays will work, Petcore Europe says. However, the important question is whether industry can develop these technologies to an industrial and economically feasible scale.