紙の動的ぬれの測定について

抄録

Wettability of paper surface is fundamentally important in determining penetration and/or absorption of water into the paper, for instance, as in the case of a ink jet printer.
Therefore, contact angle of a water drop on paper surface with lapse of time was dynamically measured by means of a system consisting of an automatic syringe, an automatic rewinding camera, a stroboscope with a signal controller and a photo pick-up with a laser oscillator. The contact margin and profile of the drop was continuously photographed in every 10 ms.
Contact angle of a water drop on wood-free papers decreased with time during the initial 30 ins and then fluctuated periodically at a certain level. On the other hand, ink jet papers showed significantly sharp decrease in contact angle and no fluctuation. Influences of some paper-making factors, such as grade of pulp, degree of beating and wet pressing, degree of sizing and others, on the dynamic behaviour of contact angle were investigated.