The challenges for cellulose packagings

Author :Benoit Bideau, Innofibre

The packaging sector is a complex field that must meet diverse needs depending on the types of contents involved. The nature of these will shape the packaging itself and its properties. For example, computer equipment requires a packaging that is, before all, shock resistant; meat packaging requires an oxygen-proof barrier to reduce oxidation and food degradation; dry cakes require moisture barriers to prevent an increase in moistness levels before reaching the consumers. Thus, each type of packaging must be optimized according to its contents.

Nowadays, most of the packaging in our daily lives is made of plastic (polyethylene, polypropylene, etc.) because they can meet all the requirements at a low cost. These pure materials or composites (mixtures) have absolute barrier properties against water, grease, and oxygen. Furthermore, they can be extruded, injected, or thermoformed easily at phenomenal production rates and low costs. Therefore, it has become a real challenge to reinvent the packaging industry without using plastics and simultaneously maintaining the same level of barrier properties.

On another level, increasing awareness concerning the need to preserve our planet, as well as, changes in consumer behaviors, are pushing companies to reconsider their packaging materials to offer more environmentally friendly products. It is only natural that they turn to bio-based and biodegradable products. In these categories, cellulose-based materials such as paper and cardboard are the most suited materials to replace plastics.

To achieve the desired properties, the use of innovative coatings must be examined to maintain the biodegradable or compostable aspect of a packaging. Indeed, PET-based coatings, although they offer the desired properties, pose a real challenge for recycling centers, and unfortunately often end up in landfills.

In this context, Innofibre is contributing by researching on innovative bio-based coatings derived from renewable resources that are not in competition with food crops and that result from the principles of green chemistry (ecological process). Thanks to its multidisciplinary expertise in the treatment of paper products, this research center is actively working on water and oxygen barrier properties, as well as bioactive coatings to eliminate infectious agents that react upon contact with certain products. Several projects are underway for testing materials such as starch, lignin, microfibrils, cellulose nanofibrils, and many other secret recipes to assist industrial partners in finding solutions. Innofibre also collaborates directly with other packaging research centers to stay closely aligned with the reality of the market and to understand the needs of various packaging types, while maintaining an ecological focus. In fact, the main challenge is to develop bio-based formulations that provide multiple barriers simultaneously, such as food trays that possess both oil and water barriers.

These coatings will then be applied using various coating processes, either on paper, cardboard, or even thermoformed cellulose-based products that are increasingly favored by both industries and consumers. In the latter case, the application becomes more complex due to the geometric shapes involved. However, Innofibre is now equipped with a unique pilot system in this field, which will address the needs of the industry, representing a major advancement for thermoformed products.

As we can see, there are numerous challenges involved in the transition towards replacing plastic products, but each project contributes a little more to finding a replacement solution. The next step will be to discover ways to produce paper bottles, but for the moment, that is a whole other chapter…