VTT and Aalto University develop packing material from fibril pulp
The method developed by VTT and Aalto University enables industrial scale roll-to-roll production of nanofibrillated cellulose film, which is suitable for example for food packaging to protect products from spoilage.Nanofibrillated cellulose typically binds high amounts of water and forms gels with only a few percent dry matter content. This characteristic has been a bottleneck for industrial-scale manufacture. In most cases, fibril cellulose films are manufactured through pressurized filtering, but the gel-like nature of the material makes this route difficult. In addition, the wires and membranes used for filtering may leave a so-called “mark” on the film, which has a negative impact on the evenness of the surface.According to the method developed by VTT and Aalto University nanofibrillated cellulose films are manufactured by evenly coating fibril cellulose on plastic films so that the spreading and adhesion on the surface of the plastic can be controlled. The films are dried in a controlled manner by using a range of existing techniques. Thanks to the management of spreading, adhesion and drying, the films do not shrink and are completely even. The more fibrillated cellulose material is used, the more transparent films can be manufactured.Several meters of fibril cellulose film have been manufactured with VTT’s pilot-scale device in Espoo. All the phases in the method can be transferred to industrial production processes. The films can be manufactured using devices that already exist in the industry, without the need for any major additional investment.VTT and Aalto University are applying for a patent for the production technology of NFC film. Trial runs and the related development work are performed at VTT.The nanofibrillated cellulose grade used was supplied by UPM.