Crystalline Polyethylene Terephthalate, abbreviated as CPET, is a cost effective alternative to aluminium trays. Færch Plast A/S has manufactured plastic packaging with CPET since 1986 and it is a particularly popular product in the UK:
“The UK is a large market for ready meals and CPET trays are a very popular type of packaging because consumers can take a CPET tray directly from the refrigerator or freezer and place it in the oven. This plastic can work within temperatures from -40°C to 220°C,” explains Thomas Lynggaard, Senior Materials Specialist at Færch Plast.
Flexibility and strength
And there are more advantages with CPET. While aluminium trays easily become deformed, CPET trays return to their original form after impact. Furthermore, aluminium trays do not provide the same freedom of design as a CPET tray, as the material is too unstable to be used for multi-compartment trays.
“CPET provides greater flexibility because the material is very mouldable and allows for the design of a tray with more than one compartment. This is advantageous if the tray is designed to hold a ready meal with meat and vegetables, as the quality of the vegetables is improved by storage in a separate compartment,” says Thomas Lynggaard.
The CPET trays can also be manufactured in dual colours. This improves the aesthetics compared to conventional aluminium, while the options of colour printing and a logo provide differentiation on store shelves. In the UK ready meal market, dual-coloured CPET trays have been a direct path to increased sales for food producers.
Crystallisation process makes the difference
The technology behind Færch Plast’s production of CPET trays is, as the full name suggests, a crystallisation process. Whereas regular PET plastic trays are manufactured by heating a film, forming it in unique dimensions in a moulding machine and then cooling it, a CPET process is more complicated.
“In the production of a CPET tray, the material undergoes a special crystallisation process making it dimensionally stable and usable for temperatures up to 220°C. If the material was not subjected to the crystallisation process, it could only be used for temperatures up to 70°C,” explains Thomas Lynggaard.
CPET is also a sustainable packaging solution, as the product primarily contains rPET, which is recovered from plastic bottles and other sources. These recovered materials undergo a cleaning process to ensure that the material is subsequently approved for food use. Replacing PET with rPET reduces carbon emissions by 50% and all of the trays containing rPET are equipped with a top layer that serves as a functional barrier, providing high food safety.
In 2014, Færch Plast won the Snack d’Or Award at the Sandwich & Snack fair in Paris for a new and innovative pizza tray concept in which the tray is made with CPET.
Advantages of CPET packages:
- Suitable for use in microwaves, conventional ovens, pasteurisation and sterilisation
- Easy to separate and stack
- Unique design
- Stability and durability
- A sustainable solution that benefits the environment with lower carbon emissions
- High food safety