Pre-treatment of MFC controls properties and energy consumption

Mikael Ankerfors, standing to the left, congratulated by Torgny Persson, Business area Director Material Processes, Innventia.

On 17 October, Mikael Ankerfors obtained his licentiate degree with his thesis “Microfibrillated cellulose: Energy-efficient preparation techniques and key properties”, which summarizes the effects of research within this field at Innventia.

The forest industry is looking for new business opportunities and products, and nanocellulose is an exciting possibility. Nanocellulose, also known as microfibrillated cellulose (MFC), is a potential bulk product with possible uses including as a strengthening component in other materials, such as paper and bioplastics. It could also be used in a diverse range of applications such as barrier materials for packaging, food additives, cosmetics, pharmaceuticals and electronics. At Innventia, research has focused mainly on the actual process – being able to produce nanocellulose in a way that is as energy-efficient as possible – and many advances have been made. Based on these research findings, a pilot facility was built in 2010 to produce nanocellulose in sufficient quantities for further development towards practical applications.

Mikael Ankerfors’ thesis describes three alternative processes for producing MFC, in which pulp fibres are first pre-treated and then homogenized using a high-pressure homogenizer. In one process, fibre cell wall delamination was facilitated with a combined enzymatic and mechanical pre-treatment. In the two other processes, this was done by introducing anionically charged groups into the fibre walls. All three processes are industrially feasible and enable production with considerably lower energy consumption – 91-98 percent lower – than that presented in earlier studies. By optimizing this pre-treatment, the quality – such as a film’s mechanical and optical properties and oxygen barrier – can be improved. The materials produced have been characterized in various ways, and it has been demonstrated that the MFCs produced are approximately 5-30 nm wide and up to several microns long.

Nanocellulose is an important part of Innventia’s research into material processes. Mikael’s licentiate thesis now provides a summary of various research collaborations in recent years.

“This work is an effect of international cooperation within projects financed by the EU and VINNOVA, as well as work within Innventia’s industry-financed Cluster Research Programme,” he explains.

“A great deal is being done by many different players, and I am delighted to be able to present a thesis summarizing some of what we can currently achieve when it comes to MFC.” “We hope that MFC will become a commercial product,” says Torgny Persson, Director of Business Area Material Processes at Innventia. “For example, Stora Enso is now investing in a pre-commercial production facility in Imatra. The research carried out together with the pilot facility is absolutely crucial in order for companies to make further progress.”