The microwavable plastic container market is one that is dominated by polyolefin materials, and more specifically, PP. Not only do these containers often fail to be recycled, but tests have also shown that additives in the polymer can migrate into the food during heating. Thermapet Technologies offers a safer, more sustainable option: TPET.
Amorphous PET, or APET as it is usually called, is produced through a manufacturing process that includes the rapid cooling of the material, preventing the polymer chains from crystallising and resulting in a transparent material with excellent clarity.
Because of that, it is the material of choice for packaging applications that require critical transparency and visibility of contents. However, it is generally not suitable for microwaving or oven use.
Now, a young Singapore-based startup claims it has found a solution for that. Thermapet Technologies has developed and patented what it describes as ‘revolutionary’ technology for producing a fully circular APET for trays and cups. Called TPET, it is produced from virgin or recycled PET without the use of nucleating agents or additives. Offering high temperature resistance, which has been tested up to 220°C , TPET can therefore be used in both the microwave and the oven, thus closing the gap between PET-based products and polyolefin alternatives. Suitable for high-temperature microwavable trays and hot pour applications, the material even has the potential to replace the aluminium used in products such as in-flight meal trays.
Game-changing technology
The development is exciting in more ways than one. Plastic has become an essential part of our modern lives due to its affordability and versatility, but its lasting environmental footprint is a critical concern. Plastic waste, which takes hundreds or thousands of years to decompose, is becoming an indelible part of our fossil record. Single-use plastic packaging waste poses a threat to public health, the environment, and the economy. Often contaminated, recycling it can be a challenge.
As well, ambiguity reigns regarding the definition of quality in regard to recyclate, and a framework to implement such quality in the recycling process is lacking. There is currently not enough recycled plastic of sufficient quality for key packaging applications, making it unlikely - in Europe, at least - that upcoming recycled content commitments will be met. PP markets include food packaging, sweet and snack wrappers, hinged caps, and microwaveable containers. About 70% of PP used in packaging goes into injection-moulded pots, tubs, and trays. However, recycled PP from rigid packaging currently meets only 3% of the demand, while the newly adopted PPWR – the Packaging and Packaging Waste Regulation - mandates that by 2030, the EU must incorporate at least 10% recycled content in all packaging, increasing to 50% by 2040.
By contrast, PET packaging offers 100% recyclability. Thermapet’s solution addresses the challenges posed by traditional single-use plastics, providing an environmentally friendly alternative that is both durable and circular.
The microwaveable polymer container market reached an estimated volume in 2023 of some 25 million tonnes, of which more than 90 % are accounted for by polyolefin-based products due to their easy availability and relative temperature stability.
Traditional plastic containers designed for heat applications often rely on added agents. Thus, even though the temperature stability of polyolefins like PP is only up to 100 oC, by patching those products with stabilisers and other materials, they can pass the 120 centigrade thresholds for a short time, passing the microwavable certifications. However, these products are not circular.
Thermapet aims to replace polyolefin-based microwavable containers with a fully circular and APET based alternative that can reach temperature stability up to 220°C, providing a fully retort and oven-able alternative.
"Thermapet aims to enable a truly circular approach to packaging by focusing on high-quality, recyclable PET," said Thermapet’s COO Kris Withouck. "Our solution provides the same durability and function as single-use plastics without the environmental cost."
The innovation lies in a process called ‘PET Forming’, which allows for the production of heat-resistant PET containers up to 220°C without nucleating agents or additives. Thermapet’s containers are made from pure PET, enabling them to enter the bottle-to-bottle recycling stream - the only fully circular recycling system in existence.
The company’s additive-free approach means containers made from TPET can be recycled indefinitely through Solid-State Polycondensation (SSP), restoring them to near virgin quality with every cycle.
The new APET can help the industry meet the requirements of regulations like the PPWR in the EU and support the efforts of the United Nations to limit singular plastics, providing the industry, consumers, and legislation authorities with the first real alternative since PET bottles.
TPET will hit the market in 2025.
