There have been ‘smoothwall’ aluminium trays for whole birds, thermoformed skinpacks and film portion packs. But when it comes to poultry cuts, for instance, there is an almost universal category language of clear polypropylene (PP) trays among the major UK retailers. This offers lower costs – but also less barrier protection – than polymers such as polyethylene terephthalate (PET).
There are exceptions. “Morrisons is using foamed polystyrene (PS) for red meats, and would like to do the same with poultry,” said innovations director at Linpac Packaging Alan Davey. As well as the ‘freshness’ connotations, he argued, foam offers lower costs and a smaller carbon footprint.
Foamed trays have clear weight benefits, too. And overall, weight reductions have been a prime objective for many retailers. Sharp Interpack reported a 25 per cent reduction in tray weights over a two-year period. But neither foamed PS nor, currently, PP are widely collected for recycling, while Faerch Plast emphasises the monomaterial benefits of its PET packaging for this very reason.
According to UK managing director Joe Iannidinardo, the company is targeting the red meat sector with its MAPET trays. These are modified with a heat-sealable layer of PET, rather than the more traditional polyethylene (PE). Here, as elsewhere, recycled PET content is an option.
Similarly, Sharp Interpack and Linpac are stressing post-consumer recyclate (PCR) content in their PP trays, in this case blending virgin PP with PE from recycled milk polybottles and a mineral filler.
At the same time, the Waste & Resources Action Programme (WRAP) has helped to move the sustainability agenda on to food waste. Some would argue that the scale of this problem justifies the use of more packaging. In fact, the food waste argument could favour the use of flexible packs thermoformed inline, rather than rigid trays of any description.
At equipment supplier Multivac, marketing manager Andrew Stark said: “They are a cost-effective alternative to rigid premade trays, offering lower pack costs, higher production speeds and reduced packaging waste. They can also have portion control built in.” Marks & Spencer has innovated with this, wrapping each portion separately inside a ‘mother bag’ to facilitate home freezing.