Plastic, yes please!

A recent study shows that plastic sacks are the most sustainable packaging solution for cement: AD*STAR cement sacks made of coated polypropylene fabric achieve considerably better results than sacks made of paper or recycled polypropylene tape fabric.

The effects on the environment, a much discussed topic regarding plastic bags for everyday use, also play an increasingly important role for industrial packaging. A new study which compares different types of cement packaging now proves that woven plastic packaging is the most environmentally friendly solution for this application. The results of the life-cycle-analysis, carried out by the German PE INTERNATIONAL and commissioned by the Austrian machinery supplier Starlinger & Co., clearly show that AD*STAR sacks – welded block bottom valve sacks made of coated polypropylene tape fabric – have lower global warming potential (also known as carbon footprint) than paper sacks or sewn PP sacks which are widely used especially in Asia. For comparison, sewn sacks made in China as well as kraft paper sacks made in Saudi Arabia were analysed; all sacks had a filling capacity of 50kg cement.

The results are clear: The AD*STAR sacks developed by Starlinger do not only show the lowest values regarding global warming potential, they are also the most environmentally friendly packaging in terms of acidification potential (acid rain), ozone depletion potential, photochemical ozone creation potential (causes summer smog), as well as energy and fresh water consumption.

A decisive factor for the positive results of AD*STAR sacks are the low breakage rates in the course of the life cycle of the sacks. For the production of the AD*STAR sacks analysed in the study, 100 per cent virgin material was used both in China and Saudi Arabia. Due to the special production process AD*STAR sacks are extremely robust despite their very low weight. The strength and resistance results in breakage rates below one per cent in the entire life-cycle, while paper bags and sewn sacks have breakage rates between 2.3 per cent and 4.4 per cent. This means that if AD*STAR sacks are used, less cement is lost and must be replaced, and less packaging is needed – consequently, less greenhouse gases are produced.

The study analyses the environmental impact of the sacks during their entire life-cycle – from raw material to the disposal of the sack. Raw material production, sack production, filling, transport and storage until disposal – by means of landfill, recycling or thermal utilisation – were analysed.

Starlinger has commissioned the study with comparable products from China and Saudi Arabia because the type of cement packaging analysed forms the biggest share on the cement market in the respective country. In China, the world’s biggest cement producer, around 20 billion sewn cement sacks made of polypropylene tape fabric with recycled content are produced. In the study, sacks made of 50 per cent virgin material mixed with 50 per cent recycled material, and sacks made of 100 per cent recycled material were analysed. The quality of the sacks is comparatively low because the recycled material used to produce the sacks is in most cases severely degenerated, i.e. the necessary level of strength can only be achieved by increasing the fabric weight.

The worldwide used AD*STAR sacks have been developed and patented by the Austrian mechanical engineering company Starlinger & Co. The company is a leading supplier of machinery and complete plants for the production of woven plastic packaging and has installed AD*STAR production plants with a total yearly capacity of more than 7.5 billion sacks all over the world.