Process for the production of nano-fibrillar cellulose gels

A nano-fibrillar cellulose gel obtained by the process comprising the steps of:

• (a) providing cellulose fibres contained in pulps selected from the group consisting of eucalyptus pulp, spruce pulp, pine pulp, beech pulp, hemp pulp, cotton pulp, or any mixture thereof;
• (b) providing a filler;
• (c) combining the cellulose fibres of step (a) and the filler;
• and
• (d) fibrillating the cellulose fibres in an aqueous environment in the presence of the filler from step (c) until a nano-fibrillar cellulose gel is formed;
• wherein the formation of the gel is verified by monitoring the viscosity of the mixture in dependence of the shearing rate, wherein the viscosity decrease of the mixture upon step-wise increase of the shearing rate is stronger than the corresponding viscosity increase upon subsequent step-wise reduction of the shearing rate over at least part of the shear rate range as shearing approaches zero;
• wherein the filler is natural ground calcium carbonate,
• wherein in step (d) the weight ratio of fibres to filler on a dry weight basis is from 1:33 to 10:1, wherein the Brookfield viscosity of the nano-fibrillar cellulose gel formed in step (d) is lower than the Brookfield viscosity of a corresponding nano-fibrillar cellulose suspension having been fibrillated in the absence of the filler.