The foam technology has been developed in close collaboration between Unilever, Mucell Extrusion and Alpla. This is the first time this technology has been applied to HDPE bottles. It enables the creation of a foam layer (containing air) sandwiched between two layers of 'solid' HDPE. It remains a mono-material HDPE bottle. The weight has been reduced by over 14% from 21g to 18g. Over a full year and for Europe only, this represents a saving of around 275 tonnes of HDPE.