Method for manufacturing nanofibrillated cellulose pulp and use of the pulp in paper manufacturing or in nanofibrillated cellulose composites

Abstract

A method for manufacturing pulp. The manufactured pulp includes at least 30 w-% nanofibrillated cellulose material measured from the dried pulp. A raw material is introduced to a system. The raw material includes cellulose. At least one type of an optical brightening agent is dosed as a refining additive to the system. The raw material is refined in the presence of the dosed optical brightening agent in at least one pre-refining stage or fibrillation stage to form fibrillar cellulose material.

Description

FIELD OF THE INVENTION[0001]The invention relates to a method of manufacturing nanofibrillated cellulose pulp. The invention further relates to use of the pulp in paper manufacturing or in nanofibrillated cellulose composites.BACKGROUND OF THE INVENTION[0002]Many stages of pulp production, especially refining stages, consume lots of energy. Specially a production of nanofibrillated cellulose consumes a great deal of energy due to several fibrillarion passages that are needed to achieve nano-sized material. Because the energy consumption of the manufactured pulp increases hugely when the produced pulp includes nanofibrillated cellulose, there may be an efficiency problem when the produced pulp consist at least partly of nanofibrillated cellulose. Sometimes another problem in the nanofibrillated cellulose pulp production is poor water removal due to several strong bonds between cellulose fibers and the water to be removed.[0003]Due to the above mentioned problems, it is beneficial to ...

AI Technical Summary

Benefits of technology

[0007]The inventors of the present invention have surprisingly found that optical brightening agents can increase the production efficiency of the nanofibrillated cellulose pulp if the additives are dosed before or during a pre-refining stage and/or a fibrillation stage. Optical brightening agents have been found to be able to create bonding with cellulose in such a way that the optical brightening agents can act as substituents in inter-fiber bonding and, thus, inhibiting hydrogen bonding of fibrils in cellulose. The increased production efficiency is mainly due to decreased energy consumption of the fibrillation st

Problems solved by technology

Many stages of pulp production, especially refining stages, consume lots of energy.

Specially a production of nanofibrillated cellulose consumes a great deal of energy due to several fibrillarion passages that are needed to achieve nano-sized material.

Because the energy consumption of the manufactured pulp increases hugely when the produced pulp includes nanofibrillated cellulose, there may be an efficiency problem wh

Images