摘要 |
<p>A paper sheet of paperboard, such as boxboard, cardboard and the like has one surface coated with a surfactant to prevent, or at least retard the penetration of moisture through the thickness of the paperboard to the other surface thereof. A method of making a paper sheet or paperboard which has an improved resistance to or retards the penetration of moisture through the thickness of the paperboard comprises the sequential steps of applying a thin coating of a surfactant to one surface of the paperboard, and immediately drying the coated surfactant on the paperboard.</p> |