SIG Combibloc (Neuhausen / Switzerland; www.sig.biz), manufacturer of composite cartons and filling systems for beverages and liquid foods, has now extended its aluminium-free “combibloc Ecoplus” solution to the square one-litre “combiblocMidi” format, alongside its rectangular (base) format variants.

A special, unprocessed paper board ensures the stability of the aluminium-free cardboard composite. It also shields the food in the carton from light. A layer of polyamide provides a barrier to protect against any loss of aroma and blocks foreign aromas. The carton additionally has layers of polyethylene on the outside and inside. The inside layer forms a liquid barrier for the product while the outside layer keeps out moisture. Together, they ensure the sealability of the carton.

Since it was brought onto the market in 2010, more than 1 bn cartons in the aluminium-free version have been sold. The first products packed in the square-base format will be available in Spain, filled by the Leche Celta dairy.

The packaging has initially been designed to fulfil the barrier requirements for UHT milk. “It is conceivable that, later on, corresponding packaging materials will be introduced to meet the barrier requirements for plant-based beverages, special forms of liquid milk products or the specific barrier requirements of non-carbonated juice products,” a company spokesperson explained when contacted by Plasteurope.com.

Aluminium layers in aseptic carton packs protect the food from light, oxygen, foreign aromas and aroma loss. A life-cycle assessment of a carton pack, however, shows that while the weight component of the aluminium layer in a conventional one-litre carton pack is more than 10 times lower than the weight component of the paper board, the share of aluminium accounts for considerably more carbon emissions over the full product life cycle of the carton pack than the share of paper board.