INTRO: Another brik in the landfill?
Billions of beverage cartons are consumed every year: they come in all shapes and sizes, can hold anything from fruit juice to beans, soups or milk and are as conspicuous as tin cans or glass jars. Many big brands use them (Innocent Drinks, Ribena, Tropicana, Covent Garden soups… etc).
Due to the length of the post, I have divided in two parts
A carton by any other name…
Tetra Pak, the leading carton manufacturer, and Tetra Brik is a brand name for a carton package is even a household name. In this post I will be using the terms “brik” and “carton” indisitinticvely.
The name ” Tetra Brik”was derived from the tetrahedron-shaped packaging, which required minimal material with maximum hygiene. The Tetra-Pak packaging business was founded in Lund in Sweden in 1951 by Ruben Rausing. The first Tetra-Pak machine was delivered in 1952, which packaged cream in 100ml cartons
Milk packaging was not developed until 1954, when the first Tetra-Pak machine was exported to Hamburg. The company has now grown to be the largest food packaging company in the world by sales, with the company still being privately held and now known as Tetra Laval. In 2011, the company had sales of €12.7bn.
Their main competitors, Norwegian company Elopak and Swiss outfit SIG Combibloc are a bit far behind in terms of sales:
Tetra Pak cartons are primarily made from paper. 75% of the Tetra Pak carton is made from paperboard, 20% of polyethylene and 5% of aluminium. A 1L carton for milk weights about 30 gr. These three materials are layered together using heat and pressure to form a six layered armour which protects the contents from light, oxygen, air, dirt and moisture Refrigerated products don’t need the same barrier properties, so cartons for pasteurized milk, for instance, have no aluminium.
Are briks sustainable ?
Briks are made mainly of paper (100% certified FSC standard) paper. They are an example for logistic optimization, before being erected (the laminate it’s transported in reels ) as well and later (the prism or “brick” shape can more efficient to pack and ship), and they very are also very light (4% packaging to 96% product by weight, or put it in other way 1L carton for milk weights about 30 gr).
Doing an eagle-view LCA increasingly preferring scientific evidence to heart-felt assumptions, a number of LCAs have been produced over the last few years.
In the case of milk containers, independent Life Cycle Assessments (LCAs, for example 1 and 2 ) show cartons to have a lower environmental impact that the alternatives (HDPE or PET) bottles, specially so in larger volumes (1or 1.5L). In India and China pouches (see a couple of suppliers: 3, 4) are common for UHT milk (they were also popular in Europe and some other parts of the world for pasteurized milk). The first LCAs mentioned compare cartons and pouches for pasteurized (refrigerated) milk. There’s a thorough 2011’s report by the Eidgenössische Technische Hochschule Zürich (ETH Zurich) for aseptic packaging in general that includes LCAs for pouches and cartons.
Beyond milk, a peer-reviewed study commissioned by Tetra Pak for soup containers, which compared the Tetra Recart or TRC (which allows sterilization in the carton and it’s used for vegetables, sauces, soups… etc) with steel cans and laminated pouches. The cartons showed less impact in all categories (Total Energy, Non-fossil energy, Global warming potential, Acidification potential, Eutrophication potential, and Smog formation).Source: https://assets.tetrapak.com/static/documents/sustainability/tetra-recart-soup-lca-2014.pdf
Cartons showed less impact in all categories but two:
- Eutrophication: due to water emissions from papermaking
- And Total non-fossil energy: cartons have a larger share of non-fossil energy, associated with biomass feedstock and process energy for paper content of the TRC rollstock.
Total energy is similar for cartons and pouches; material energy higher for TRC, but pouch has much higher secondary packaging requirements. Also surprisingly, pouches have higher solid waste than cartons as you seen in another graphic from the mentioned study.
This is due to the material waste during production:
Another study comparing the environmental footprint of cartons (SIG’s Combibloc in this case), glass jars, tin cans and retortable pouches came up with similar conclusions. The comparative LCA led by the German institute IFEU, measured performance in eight categories. Cartons came ahead in all but one category (use of nature, because of their use of trees). The study showed that cartons’ total primary energy consumption was the lowest of all four systems. The difference was even starker for CO2emissions, with pouches emitting 57 per cent more CO2 over their life cycle than cartons, tin cans 120 per cent more and glass jars 150 per cent more.
Both studies put the differences down to raw material, weight and shape. Cartons’ main raw material is wood, a renewable source, and paper mills use wood dust and waste as their main source of energy to convert it to paperboard. Steel, glass or aluminum containers on the other hand need large amounts of fossil fuel to convert their respective raw materials. Then there’s the light weight and the rectangular shape, two attributes that make cartons highly efficient in
Tetra Pak’s website shows many examples of LCAs for other products, and finally, a Master Graduation Thesis from the university if Milan summarizes 12 multi-material packaging LCA studies, and generally cartons are the containers with less impact in most categories.
To be continued…
May 2018, Bruno Rey – The Packaging Blog –