Food Engineering

Food Packaging: Are minerals the new plastic?

June 4, 2006
A controlled atmosphere packaging system (CAPS) ostensibly was the what's-new element in the Ecolean Group booth at Cologne, Germany's Anuga FoodTec show in April, though for many West European liquid food and beverage processors, the company's entire line is new. Ecolean entered the commercial packaging market seven years ago, beginning in Russia and China and expanding westward into eastern and central Europe. Food companies in Spain, the UK and elsewhere are beginning to use the packaging system.

Calcium carbonate produces a strong yet light packaging material, resulting in containers weighing about half as much as a comparable gabletop and one-third of high density polyethylene. The latest version incorporates an inflated handle for added support. The original pouch provides holes for gripping. Source: Ecolean Group.




Calcium carbonate-essentially chalk-replaces petroleum resins as the main structural component in Ecolean's Calymer packaging film. The mineral accounts for 40 percent or more of film structure. Calcium carbonate also is the main component in egg shells, which rely on a protein matrix to hold the mineral together. In Ecolean's case, a polyolefin such as polyethylene or polypropylene is the binding agent. The result is a tough but flexible film with a distinctive tactile quality.

"It has a soft feeling that I would describe as a velvety touch," offers Lars-Eric Andersson, head of worldwide marketing at Helsingborg, Sweden-based Ecolean. Chalk granules also lend strength and stability, resulting in ultrathin film weighing half as much as a comparable gabletop carton and a third of HDPE. "Our 1 liter pouch has a wall thickness of 150 microns," says Andersson.

Five years ago, Hans Rausing, former chairman and CEO of Tetra Pak and Tetra Laval Group, became Ecolean's principal investor. He helped shape a business model similar to Tetra Pak's: preformed, printed pouches on rollstock are sealed and shipped to customers for filling on specially fabricated machines that open, fill and seal each pouch in 2.4 seconds in a hygienic enclosure. In the newest design, the filling machine inflates an air-filled handle, adding structural support to the pouch. Simple engineering and compact size were design principles for the fillers, which are about 6 meters in length (19.5 ft.) and fill up to 100 units a minute, depending on pouch size. The gusseted pouches self-seal after opening.

The use of nitrogen and carbon dioxide to extend fluid dairy products' shelf life is unheard of in Europe, making the CAPS component on the fillers "a big leap forward," according to Andersson. By injecting gas into the headspace, shelf life triples. Some processors report gains of a couple of days even without modified atmosphere, thanks to the hermetic sealing and clean-room production of the rollstock.

Calymer's relatively benign polymers are compatible with plastic recycling programs and photo-degrade in a fraction of the time of PET or HDPE. When incinerated to power electrical turbines, the calcium carbonate helps neutralize acid emissions and minimize metal corrosion.

A current limitation is product temperature: a maximum temperature of 50