Nowadays, most of the food we buy is packaged. The packaging makes it easier to handle, transport and protect food against impact and pressure, light, moisture, oxygen, microorganisms and impurities. The packaging also helps to preserve the nutritional value, taste and smell. Usually, plastic or paper packaging materials are used as well as glass and metal.
From a consumer perspective, it is important that the packaging is safe and that it protects the food, and that the chemical constituents of the material do not transfer to the food.
The material that is closest to the food by type is usually, but not always, the best material. Cardboard packaging materials, when in contact with food, are coated with a barrier material – in many cases, some type of plastic. But these fossil-based materials may also contain components that migrate to the food.
“We are about to crack the code on how to coat paper and board with a fossil-free barrier material. This is something no one has previously been able to do on an industrial scale,” says Per Emilsson, sales manager at UMV Coating Systems.
Thin and dense layers
“In our pilot plant, we have made a number of successful test runs where we coat cardboard and paper during a normal production speed of 400 meters per minute. We add on a thin film of our patented bio-based coater called INVO® Coater and complement it with INVO® Tip,” continues Per Emilsson.
“Compared with other techniques INVO® Coater can be both applied and recharged at the same time. The coating is applied on the surface where the barrier has the greatest effect and INVO® Tip uses a soft tip that follows the changes in the paper’s structure. The result is a thin and smooth layer, a prerequisite for quick drying. We also avoid the pores in the barrier that have been a common problem with bio-based barrier materials.”
The new barrier properties were tested in collaboration with researchers at Karlstad University. A battery of standardized methods of food packaging was used and the initial evaluations were positive. “Soon, board and paper producers will have the opportunity to use the technology on an industrial scale,” says Emilsson.
Several environmental benefits
The tested fossil-free barrier materials are made of starch and a polyvinyl alcohol polymer. Both materials make it possible to recycle cellulosic fibers in the packaging or alternatively to compost the waste.
“We have daubed the carton with a thin film about 6 μ (microns) thick when wet. After the film has dried the thickness is reduced to 1-2 μ. Using a thin layer provides significant energy and environmental benefits in the drying process. It also reduces the consumption of coating material by 15-30 percent,” says Emilsson.
The picture shows the coated paper from one of the test runs at UMV’s research and development department in Säffle.
The world market for growth
The world market for barrier coating of paper and board was estimated at $ 5.1 billion in 2013 and 4 percent growth is expected per year. Interest in biodegradable packaging is growing rapidly and developing packaging materials that meet stringent future environmental requirements has become a priority.
At the same time, consumer demands for functionality and legislators’ protection requirements of the packaged product must be met. Additionally, the packaging gives food manufacturers the opportunity to provide information on product characteristics and market it through interesting designs. This is an equation with many parameters and where a fossil-free barrier material can have a distinct environmental benefit.
This article was published in October 2104