Eco-friendly cardboard can replace plastic packaging

LUT has developed a new form of cardboard-based packaging for foodstuffs and other basic items that is airtight enough to easily protect perishable goods. The prototype, which uses gas seals, has been produced using LUT's own production line. The results of the research project are suitable for use in commercial production processes.

In the future, this new type of ecological cardboard packaging will be a worthy replacement for the plastic commonly used in the packaging of everyday goods.

"Achieving the right surface quality to contain the sealant gases proved to be the deciding factor in the manufacturing process for the cardboard packaging. The prototype packaging trays we've made using compression technology do not have joins. We've developed the manufacturing processes for the packaging, the technology for the production tools, and the sealant components", says Project Manager Mika Kainusalmi from LUT's Department of Mechanical Engineering.

The trays are manufactured using the flexible packaging production line developed and built by LUT's packaging technology laboratory. According to Mika Kainusalmi, the production line can make minute adjustments for the purposes of research, and it is this that has enabled them to produce such high quality packaging. This type of production line is not currently commercially available. 

Towards a plastic-free future

The research has been primarily carried out using commercially-available card and plastic materials, but test batches of the packaging have also been made with cardboard that has been coated with a bio-based material developed at LUT. The goal is to completely replace PET-based plastics with new bio-based products.

"The bio-based coatings developed by LUT Chemtech, LUT's School of Chemistry and Technology for Industrial Applications, are looking promising, but there's still room for improvement when it comes to the seal. We managed to get close to the quality of seal required by adding a small amount of a synthetic polymer to the biomaterial mix. The development work is still continuing."

The eventual research results will be beneficial for all areas of the packaging industry, including card and film manufacturers and firms that make the machinery required for these processes.

Developing Quality Control

Alongside the packaging itself, LUT has also developed Quality Control processes for the packaging products. All of the packaging manufactured by the university's production line has been photographed with an industrial camera in order to identify any possible rips or tears. Research was conducted on the effect that different tray dimensions and templates had on the overall consistency of the product quality.

"The cameras record the properties of and colour variations in the products; for example, if light goes through the package more easily in one part or another. These observations then help us to adjust the production parameters and prevent faulty batches being made in error. We were able to achieve effective Quality Control regardless of how big or small or what shape the trays and templates were", remarks Ville Leminen, junior researcher at the Dept. of Mechanical Engineering.

The research into goods packaging will continue in November when the university is set to begin using its new Thermoforming production line. This apparatus was originally designed for use with plastic-based materials. However, LUT is attempting to modify it to better-suit the cardboard materials of the future.

The cardboard packaging development work has been carried out with ERDF funding, as part of the "Safe packaging for the future" project, which concluded on 30 September 2014. LUT served as the project coordinator, with its packaging technology and biomaterials research groups sharing the responsibility for the development work. The project was carried out in partnership with Åbo Akademi University, Turku, and VTT - the Technical Research Centre of Finland.

Further information:

Project Manager Mika Kainusalmi, tel. +358 50 919 2939, mika.kainusalmi@lut.fi

Pictured: Eco-friendly cardboard packaging Photographer: Ville Jahn.