Influence of base paper on the barrier properties of chitosan-coated papers

摘要

A kraft paper and three greaseproof papers with different porosities were coated with chitosan to see whether the cheaper kraft paper can be used as a base paper for this coating and whether the final coated paper meets the demand for a low oxygen transmission rate. The coating was performed on a bench scale and two coat weights were applied: 3.4 and 6.0 g/m~2. Besides the oxygen transmission rate, the coated material was also tested with respect to air permeance, grease resistance and water vapour transmission rate. The results showed that the coated kraft papers did not meet the target for a low oxygen transmission rate. A lower oxygen transmission rate was obtained on the greaseproof paper with the lowest porosity, where the coating stayed on the surface and formed a continuous film without cracks. The chitosan coating gave a high grease resistance on the two most dense greaseproof papers. Chitosan provided no barrier against water vapour transmission.