Production and evaluation of physicochemical characteristics of cellulose acetate porous film as an alternative for current tea bags

Given that tea bag paper is imported, production of them with other suitable materials is necessary so that porous film can be used for this application. Porous film of cellulose acetate was prepared by the dry phase inversion process and the acetone was used as solvent and ethanol as non-solvent solutions. The effect of the film permeability was investigated by changing the ratio of the solvent to non-solvent and the concentration of cellulose acetate in solutions. The ratio had a great influence on the pore size of cellulose acetate (CA) film. The best porous film was produced only in 6:4 ratio of solvent to non-solvent. Increasing the CA content (%10) in the casting solution decreased the permeability of the films. In contrast, the solubility, mechanical properties and opacity of the films increased, hence, white index did not have a significant different in the films. SEM photos illustrated that addition of low concentration of CA (%2/5) to the casting solution created a highly porous structure in the film. This study showed the good potential for application of porous CA films to achieve permeable paper as an alternative to the tea bag paper.