Manufacturing of cellulose-based paper: dynamic water absorption before and after fiber modifications with hydrophobic agents

Absorption of liquid or vapor water in paper designed for conversion processes is a critical phenomenon. In particular, the dimensional stability of the paper as the water content changes is crucial for the success of all the conversion processes, including copying and printing. Appropriate chemical treatments of the fibers can limit the phenomena of water absorption, allowing a better workability of the paper substrates. In the present study, moisture absorption tests were conducted under isothermal conditions on untreated papers and treated by coatings with silane, organo-siloxane and silicone agents, as well as with polyelectrolytes using layer-by-layer techniques. The treated and untreated papers were tested by changing the relative humidity between 0 and 80% relative humidity. The Guggenheim–Anderson–de Boer model was used to study moisture absorption isotherms, showing the increase in the dimensional stability of the papers after the chemical treatments of the fibers.