Did you know that the package of a milk carton is more complex than it looks?

The shelf-life and safety of food increased enormously due to the use of food packaging in such way that we cannot imagine a life without food packaging. Consequently, with the use of packaging materials, food waste has been strongly reduced. Plastic packaging is widely used for its exceptional barrier properties and durability. The drawback of using plastic as packaging material is their non-biodegradability causing environmental pollution. Paperboard is a sustainable replacement for plastic packaging as it is bio-based, non-toxic, recyclable, biodegradable and inexpensive. However, the barrier performance of paperboard needs to be improved by applying a barrier coating. This barrier coating is a thin layer that protects the stored food from environmental influences like water(vapor), grease, oil and various gases. Ideally, the barrier coating has excellent barrier performance for both water, oil and gases, minimizes environmental pollution and ensures easy recycling of the paperboard packaging.

In her research, Sterre Bakker from Eindhoven University of Technology, is investigating a waterborne barrier coating. The challenge of such coatings is to make the transition from a water-based coating to a water-repelling coating. This means that material that initially likes water needs to be changed into a coating that hates water. This challenge is solved by using a special resin in the coating formulation that undergoes a structural change during film formation and drying. So, the coating is fabricated in water and when it is applied on paperboard water evaporates and forms a water-insoluble coating. The main focus of this research is to investigate the relation between coating structure and barrier performance. For example, research the coating application conditions, like drying temperature or time and coating thickness and relate this to the effect is on the barrier performance. This research will help in gaining a better understanding of the mechanism behind the barrier properties, which in turn will lead to improved waterborne barrier coating for paperboard food packaging.