The longer shelf-life achievable with multilayer films in particular, means that packing as well as converting operations are increasingly going overseas, says one industry expert.

The internationalisation of the food industry and its packaging suppliers is already seeing high-performance films being shipped in from converters in central and eastern Europe, Turkey and the Middle East.

But research director at chemicals and plastics consultancy Applied Market Information (AMI) Andrew Reynolds says the offshoring process is being taken even further.

"There are UK companies packing products such as nuts, snacks and other dried foods sourced from Brazil," he says. "Historically, the packing has been done in the UK, but people are asking: why not pack them at source?"

It is not only food companies which are being kept on their toes by these incremental changes in film capabilities, says Reynolds. "Suppliers also need to understand the food companies they deal with in increasing depth."

Explaining the technical changes that have taken place, Reynolds says: "The palette of materials available in flexible packaging has never been greater. Barrier resins are much more sophisticated and there's a wider range of them." But the base material options are also more complex, with many different grades and combinations available.

Reynolds gives just one example: "Bimodal resins, which combine the best processing and performance characteristics, are now allowing polyethylene (PE) to give far greater protection to moisture-sensitive barrier resins.."