Stora Enso Oyj

Tty-saatio

Teknologian Tutkimuskeskus Vtt Oy

Taina Kamppuri

Marianna Vehvilaeinen

Pertti Nousiainen

Marianna Vehvilainen

Isto Heiskanen

Kaj Backfolk

Ali Harlin

Maija Jarventausta

Maarit Peltola

Marianna Vehviläinen

Maija Jaerventausta

Maija Järventausta

Marianna VEHVILÄINEN

A process for treating cellulosic fibers comprises mechanically pre-treating the fibers followed by treating the fibers with an enzyme and thereafter mixing the fibers with a solution comprising an alkali metal hydroxide followed by mechanically treating the fibers to form microfibrillated cellulose. In this way it is possible to produce microfibrillated cellulose (MFC) in an improved and energy efficient way.

Process for producing microfibrillated cellulose

A process for treating cellulosic fibers comprising pre-treating the fibers with an enzyme in a first enzymatic treatment followed by mechanical pre-treating the fibers in a first mechanical treatment and a second enzymatic treatment followed by a second mechanical treatment of the fibers to form micofibrillated cellulose. In this way it is possible to produce mircofibrillated cellulose (MFC) in an improved and energy efficient way.

The present invention relates to a method for dissolving cellulose. The method comprises&#x2014;introducing cellulosic raw material,&#x2014;treating the cellulosic raw material in an enzymatic treatment process,&#x2014;mixing the cellulosic raw material after the enzymatic treatment in an aqueous solution in order to obtain an aqueous intermediate product containing the cellulosic raw material of at least 3.5 wt.-%, alkali metal hydroxide between 3.5 wt.-% and 7 wt.-% and zinc salt,&#x2014;freezing the intermediate product to a solid state, and&#x2014;melting the frozen intermediate product. The present invention also relates to a cellulosic product obtained from a solution comprising dissolved cellulose.

Method for dissolving cellulose and a cellulosic product obtained from a solution comprising dissolved cellulose

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Tampere, Finland

Taina Kamppuri