Nampak claims increased recycled content is feasible

Container manufacturer Nampak Plastics has published research which it claims proves that its ambition to increase the recycled content in its plastic milk bottles to 50% can be realised.

The Milton Keynes-based company, which operates at eight sites across the UK, charged the University of Bradford with investigating whether it could increase the amount of recycled HDPE (rHDPE) in its blow-moulded containers.

The Bradford research has confirmed our confidence that the target of 50% rHDPE can be realised

 
James Crick, Nampak Plastics 

Nampak currently includes 10% recycled content in its milk bottles, in line with the Defra Milk Road Map, but it has also set itself the ambition of increasing this figure to 50% by 2020.

James Crick, business development director at Nampak, said: “The Bradford research has confirmed our confidence that the target of 50% rHDPE can be realised.

“This is a significant step forward and we now plan to conduct our own blow-moulding processing trials using 30% rHDPE to replicate Bradford's experimental work under manufacturing conditions.”

Nampak, which also has feedstock agreements with Closed Loop Recycling and Greenstar, signed a deal with Newcastle-based AWS Ecoplastics for the delivery of 12,000 tonnes-a-year of recycled HDPE from its Hemswell facility in Lincolnshire in October 2008 (see letsrecycle.com story).

Study

The Bradford study, undertaken by the University's Centre for Advanced Materials Engineering, assessed how the addition of variable levels of rHDPE might affect both the processability and functionality of the material. It also quantified how much rHDPE can practically be added to a bottle.

Using post consumer food grade rHDPE pellets, the experimental work assessed the properties of blends of virgin HDPE with between 10% and 50% rHDPE, and also quantified the effects on material properties of five thermal cycles through an extruder.

The researchers concluded that the recyclate grades studied had very similar properties – including flow behaviour, quality and molecular and chemical structure – to the virgin materials.

Dr Adrian Kelly, who co-led the research at the University of Bradford with Dr Leigh Mulvaney-Johnson, said: “The research has shown that the type of polymer used by Nampak is sufficiently resilient to cope with a higher level of recycled content.

“Although we did find subtle changes to the materials at high recyclate concentrations and after numerous processing steps, this wasn't at a level to detrimentally affect its strength, appearance or processability during manufacturing.”

Increasing the amount of recycled content in drinks bottles – such as milk bottles and soft drinks – has risen to prominence over the last couple of years, with heightened consumer awareness and technical feasibility of the practice being seen as two of the main drivers (see letsrecycle.com story).