Evaluation method for paper materials used in wrapping cigarettes

In order to accelerate the pace of development of environment- friendly cigarette packaging materials, which are intended to replace aluminum foil or polymer film, a method for evaluating the ability of packaging materials to prevent moisture and l-menthol migration was investigated. Firstly, a mathematical model that represents migration of the absorbable components from a pack of cigarettes was developed. The model revealed that three physicochemical properties dominate the migration rates of these components; they are the gas (vapor) adsorption equilibrium relationship of tobacco, the permeability coefficient of the wrapping material, and the apparent diffusion coefficient through packed cigarettes. These properties were experimentally determined for water and l-menthol, and the validity of the mathematical model was confirmed by comparison of the experimental results obtained using cigarettes with the calculated ones. Finally, the changes in moisture and l-menthol content in a pack of cigarettes during storage were simulated. The results showed that typical paper material cannot be regarded as a barrier to moisture migration; however, a wax coating significantly improved (lowered) the permeability of l-menthol to paper material, which suggests that wax-coated paper material could possibly become comparable with polymer film for use in cigarette packaging.