Borregaard As

Anne Opstad

Hans Henrik Øvrebø

Jarle Wikeby

Synnove Holtan

Jens-Uwe Wichmann

Sannøve Holtan

A process for the spraying of microfibrillated cellulose (MFC) is presented, which has a comparatively high solids content, onto a surface, thus forming a stable and homogeneous film coating of MFC on said surface. Therein, the MFC of the comparatively high solids content is subjected to a pressure drop in a nozzle, which pressure drop exerts shear pressure onto the MFC, thus lowering the viscosity during the spraying and coating process.

Spraying of microfibrillated cellulose

The present invention relates a process and a system for the point-of-use dilution of microfibrillated cellulose (MFC) from a higher solids content to a lower solids content, for example from a solids content in the range of 5% weight by weight ('w/w')-50% w/w, preferably 5% w/w-30% w/w, further preferably 5% w/w-15% w/w, down to a solids content of below 7% w/w, preferably below 5% w/w, preferably to a solids content of 0.01% w/w-5% w/w, further preferably to a solids content of 0.1% w/w-3% w/w. The process at least comprises the following steps: (i) providing microfibrillated cellulose in a solvent, wherein the solids content is in the range of 5% weight by weight (“w/w”)-50% w/w, preferably 5% w/w-30% w/w, further preferably 5 w/w-15% w/w; (ii) subjecting said microfibrillated cellulose from step (i) to a dilution step in a rotor-stator mixer; (iii) simultaneously to step (ii): injecting solvent into the rotor-stator mixer, or into a volume segment upstream of the rotor-stator mixer, in order to lower the solids content of the microfibrillated cellulose in the rotor-stator mixer.

Growing community of inventors

Sarpsborg, Norway

Anne Opstad