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What is Polyester?
Polyester, known chemically as polyethylene terephthalate (PET), is one of the most versatile and widely used materials in the packaging world. From your ready meal trays to fizzy drink bottles, this high-performance plastic is everywhere, and for good reason.
The Science Behind Polyester
Polyester is created by combining ethylene glycol and terephthalic acid, forming long polymer chains. These are cooled, cut into pellets, and then melted into a liquid that can be molded into virtually any shape, from bottles to films.
When stretched in two directions (biaxially), it becomes BOPET, a film with exceptional strength, clarity, and barrier properties. This makes it ideal for food packaging, electronics, and even medical applications.
Where You’ll Find Polyester in Packaging
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Lidding Films for Ready Meals
Polyester seals easily to PET trays and can be peeled off cleanly. It’s ovenable, making it perfect for heat-and-eat meals. -
Produce Punnets & Bakery Items
Micro-perforated polyester films allow steam to escape, keeping pastries crispy and fresh. -
Food-on-the-Go
Used in hot cabinets at supermarkets and service stations, polyester packaging can withstand high temperatures while maintaining food safety. -
Laminates for Dry Goods
When laminated with polyethylene (PE), polyester provides a glossy, protective outer layer for products like nuts, pulses, and baking mixes.
The Rise of rPET
With growing environmental concerns, recycled PET (rPET) is gaining traction. rPET can contain up to 80% recycled content, reducing the need for virgin plastic and lowering carbon emissions. It’s also exempt from the UK Plastics Tax, making it a smart choice for eco-conscious brands.
What About APET?
Amorphous PET (APET) is a clear, glossy version of polyester used in thermoformed trays and clamshells. It’s perfect for showcasing products on retail shelves thanks to its high transparency and rigidity.
Did You Know?
- Polyester film can be metallized to reflect up to 99% of light — ideal for preserving food freshness.
- It’s used in yoghurt pot lids, scone mix pouches, and even Pro2Go protein snack packs.
- Special ovenable inks are used to ensure food safety when printed polyester films are heated.
The Future of Polyester
As packaging evolves, polyester remains a key player — now with a greener twist. With innovations in recyclability, compostable alternatives, and mono-material structures, polyester is adapting to meet the demands of a circular economy.