CALCULATION OF THE CROSS-SECTIONAL AREA OF PLATEAU-GIBBS CHANNELS IN POLYDISPERSED FOAMS

An equation has been derived for the calculation of the cross-sectional area of a Plateau-Gibbs channel, by assuming different curvature radii of the channels (r1 greater-than-or-equal-to r2 greater-than-or-equal-to r3). By using this equation and experimental data for the actual distribution of bubbles in foams with a multiplicity factor of 25 and 240 by size, the numerical coefficient of the Leonard and Lemlich equation has been calculated. The value of the coefficient for polydisperse foams during the first minutes of existence is smaller by a factor of 2 than the theoretical value.