The packaging industry in Europe has a yearly turnover growth of 2 to 3%. The use of graphical techniques in the industry causes a need for attention to environmental issues. This has led to increased EU interest in this industry as it is economically important but may have a high environmental impact. Investigation was called for and was performed in the ECOFLEXOBAG project, an initiative of several European partners including the Dienstencentrum.

The ECOFLEXOBAG project researched the applications in which water based flexo inks can successfully replace solvent based inks. To keep the scope manageable and relevant the project focused on commercial plastic bags. Production tests done doing the project showed that it is just as possible to use water based inks as replacement for solvent based inks. As you may know, solvent based inks contribute to global warming. This is exactly what we wish to prevent.

Switching to water based inks thus looks like a perfect solution. But is it possible in all cases, and can it be achieved easily? These are the questions an entrepreneur faces before being able to switch to a new method of production.

We now know that it is quite possible to use water based flexo inks to print plastic carrying bags. If you go into a supermarket you will see – nearly everywhere – plastic bags that have been made with water based inks on recycled plastic. A good start towards making the industry more sustainable. But the question that naturally arises is whether water based inks can be used in all applications? The consumer is naturally included to swiftly respond with a ‘yes’.

In order to answer this question with authority, the ECOFLEXOBAG project focused on the production of commercial plastic carrying bags. This scope is needed, as the applications of flexible plastic packaging are legion and the resulting requirements to all these variants are more so. For printing of plastic foil, some of these are:

  • There may be no migration of ink to packaged foods, as this is a toxicity hazard;
  • The ink should be scratch resistant;
  • If the inks are exposed to daylight they should be UV resistant to prevent discoloration or separation from the foil.
  • Inks on stretch- or shrink foil should also be similarly flexible, or they will break up and off the plastic.

For production of a plastic carrying bag the previous requirements are not, or much less, important. By focusing on the production of plastic carrying bags with both water based and solvent based inks the research team was able to focus on relevant facts more objectively.

During the project the leading research institutes VTT (Finland) and AIMPLAS (Spain) performed a Life Cycle Assessment (LCA) based on equivalent parameters for both print methods. It showed that the bag printed with water based inks was indeed more sustainable than the one printed with solvent based inks. Even when one takes into account the fact that drying water based inks requires 3 times the amount of energy (as solvent based inks have a higher innate rate of evaporation). Water based inks thus seemed to be proven the more sustainable alternative to solvent based inks by the LCA.

But does this conclusion hold for other applications of plastics? This was the follow-up question that the researchers looked into together with other stakeholders (such as the EFTA and FTA Europe). The answer is ‘No’. What is going on in this case?

In 2014 problems with the use of water based inks also became apparent. Certain components of water based inks are likely to be harmful to our health if we come into contact with them. This means that water based inks cannot yet be used for food packaging. To make this possible, alterations of the water based inks are needed.

Does this mean that the flexible packaging industry is condemned to the use of solvent based inks?

Perhaps not. Recent developments exist of new print technologies: UV- or Electrobeam technology, or even digital print. As of today there are 5 print techniques in the flexible packaging industry: solvent based, water based, UV, Electrobeam and digital print. The (best) exact combination of technique, substrate and application is still unclear to the industry and will require more research. Without clear answers in this case the industry will hold on to existing conventional print techniques: solvent based and environmentally unfriendly.

This means that the life after the important ECOFLEXOBAG project should consist of more applied research. As of now there are too many unknown variables in the production process that prevent a clear determination of the best print technique in every situation. A result is large (financial) disappointments for entrepreneurs. Whatever the future may hold: ECOFLEXOBAG was a first big step forward. What is the next sustainable step?

   « news overview