Cyclic Pressing as a Viable Approach for Dewatering and Controlling Shrinkage of Micro-Nanofabricated Cellulose Films

Abstract

Cellulose films, predominantly consisting of micro-nanocelluloses, are a new type of product with interesting properties for functional packaging applications. However, the potentially scalable production methodology has not yet been elucidated. Poor dewatering and high web shrinkage are issues that need solutions beyond what is available in conventional paper production. This research investigates a cyclic pressing method that shows potential in cellulose film consolidation. Cyclic pressing allows the MNFC films to be dewatered to about 90% solids while yielding a smooth, flat product. The results show no inherent physical limits for mechanical dewatering these high swelling webs, even at very high solids. Cyclic pressing allows controlled restraint during consolidation, which could be adjusted in an industrial setup to produce even films with desirable product characteristics.

Keywords

• capillary pressing
• consolidation
• film
• microfibrillated cellulose
• nanopaper
• shrinkage
• wet pressing
• dewatering