Cellulose fiber foams have attracted significant interest in recent years as a sustainable alternative to fossil-based foams for cushioning applications in packaging. Their highly porous structure, composed of hydrophilic cellulose fibers, enables moisture absorption, making them promising for moisture-control active packaging when combined with adsorbing compounds.
This study analyzes active cellulose fiber foams containing calcium chloride (CaCl₂) at different concentrations (10, 20, and 30% w/w). The foams were treated with a CaCl₂-ethanol solution, and their structure and CaCl₂ dispersion were analyzed using scanning electron microscopy (SEM). Water vapor interactions with the cellulose foams, including water vapor adsorption and diffusion, were studied.
Moisture sorption isotherms were determined at 23°C, fitting the GAB model. The moisture content of the foams increased by 8, 16, and 25% (w/w) at 50% RH with the addition of 10, 20, and 30% (w/w) of CaCl₂, respectively. The moisture buffer value (MBV) was calculated from the sorption isotherms, and adsorption kinetics were conducted at 80% RH and 23°C. Moisture buffer capacity tests confirmed that the presence of CaCl₂ enhances water vapor retention and slows diffusion through the foam. These findings highlight the potential of these CaCl₂-cellulose fiber foams for humidity control in active packaging applications.