Mixing drying of nanofibrillated polysaccharide

Abstract

A method for drying nanofibrillated polysaccharide to obtain a substantially dry nanofibrillated polysaccharide product, comprising the following steps: (i) providing an aqueous suspension of nanofibrillated polysaccharide; (ii) increasing the solid content of said suspension, thereby forming a high solid content microfibrillated cellulose suspension; and (iii) drying said high solid content microfibrillated cellulose suspension, through a simultaneous heating and mixing operation.

1 . A method for drying nanofibrillated polysaccharide to obtain a substantially dry nanofibrillated polysaccharide product, comprising the following steps:
 (i) providing an aqueous suspension of nanofibrillated polysaccharide;   (ii) increasing the solid content of said suspension, thereby forming a high solid content microfibrillated cellulose suspension; and   (iii) drying said high solid content microfibrillated cellulose suspension, through a mixing operation, comprising a fibrillation or grinding operation.   
     
     
         2 . The method for drying as claimed in  claim 1 , wherein in step (ii), the solid contents is increased to >15 wt %. 
     
     
         3 . The method of drying as claimed in  claim 1 , wherein step (ii) comprises any one of a centrifugal force operation, pressing operation and dewatering operation. 
     
     
         4 . The method as claimed in  claim 3  wherein the dewatering operation comprises an electro-osmosis operation. 
     
     
         5 . The method as claimed in  claim 3 , wherein the pressing operation comprises a wet pressing operation. 
     
     
         6 . The method as claimed in  claim 1 , wherein at step (iii) the temperature of the suspension is in the range of 75-99° C. 
     
     
         7 . The method as claimed in  claim 1 , wherein at step (iii) the suspension is heated from about room temperature to the range of 75-99° C. 
     
     
         8 . The method as claimed in  claim 1 , wherein at step (iii) the temperature of the suspension is in the range of from 40 to 50° C. 
     
     
         9 . The method as claimed in  claim 1 , wherein in step (iii) there is further provided a simultaneous heating and mixing operation. 
     
     
         10 . The method of drying as claimed in  claim 1 , where step (iii) is performed under vacuum. 
     
     
         11 . The method as claimed in  claim 1 , wherein the nanofibrillated polysaccharide is a nanofibrillated cellulose or a microfibrillated cellulose. 
     
     
         12 . The method as claimed in  claim 1 , wherein in step (iii) there is further provided a drying additive. 
     
     
         13 . A substantially dry nanofibrillated polysaccharide product obtainable by the method as claimed in  claim 1 . 
     
     
         14 . Use of a dry nanofibrillated polysaccharide product as claimed in  claim 13  in, or for the production of composites. 
     
     
         15 . Use of a dry nanofibrillated polysaccharide product as claimed in  claim 13 , for any one of a rheology application, fixative agent, strength enhancing agent, emulsifying agent, excipient, paper applications, and in paper or paperboard of products thereof. 
     
     
         16 . The method for drying as claimed in  claim 1 , wherein in step (ii), the solid contents is increased to >20 wt-%. 
     
     
         17 . The method for drying as claimed in  claim 1 , wherein in step (ii), the solid contents is increased to >25 wt-%. 
     
     
         18 . The method for drying as claimed in  claim 1 , wherein in step (ii), the solid contents is increased to >30 wt-%. 
     
     
         19 . The method for drying as claimed in  claim 1 , wherein at step (iii) the temperature of the suspension is about 80° C.