In a pilot-scale study to find alternative materials for rigid plastic packages, VTT Technical Research Centre of Finland has developed a cellulose-based material with high extensibility.
Whilst cardboard is often used as a replacement for rigid virgin plastic packaging, typical commercial boards only have between 3% to 6% extensibility and the best commercial formable boards have between 10% and 18% extensibility. The lower the extensibility, the lower the amount of product that can be packed into the same amount of material. Given that current paper and board manufacturing processes have some major limitations, including using a lot of water and energy and having limited capability to handle different raw materials, demand for traditional paper products is decreasing while demand for sustainable plastic alternatives is increasing, VTT says on its website.
Using its foam forming technology, VTT has now obtained up to 30% extensibility for a cellulose-based web material. Foam forming technology replaces water with aqueous foam in the material’s manufacturing process, thereby having the resource-saving edge over conventional board manufacturing technologies. With up to 30% extensibility, the cellulose-based material enables brand owners to use rigid, cardboard-like packaging to serve consumers looking to buy more sustainable products. This material improvement enables food brands producing cold cuts, for example, to increase cardboard-like package size from 75 g up to 200 g to 250 g. By adjusting the tray forming process and tray dimensions even larger cardboard-like packages can be produced.
The extensible cellulose-based material is also an excellent alternative to virgin polymers, in particular polypropylene films that have extensibility of up to 300%. This March VTT announced an investment of €1.5 million into cellulose films to replace conventional plastic ones in packaging.
“Polypropylene film is one of the world’s most used polymers – its extensibility is up to 300%. Our invention now offers a viable, sustainable alternative on the market,” said Jarmo Kouko, Research Team Leader at VTT.
The material was produced in an industrial product packaging line without introducing any changes to the process.
“The fact that VTT, together with gruppo x di x gruppo s.r.l. and Lappeenranta-Lahti University of Technology (LUT), were able to incorporate the product into existing product packaging lines with no changes in the process, making it affordable and easy for brands to adopt the product as a sustainable alternative to plastic packages can be a real game-changer,” said Kristian Salminen, lead, bio-based products at VTT.
The development work has been conducted as a part of a research program, in which VTT has cooperated with 54 companies and the Regional Council of Central Finland on up-scaling promising alternatives for plastic products.