The Particular Contribution of Exposed Surface Bubbles to the True Surface Area of Machined Rigid Foams

摘要

An equation was derived, showing that the increase in area caused by random spherical bubbles breaking an otherwise plane solid surface is related to the diameters of the circles of intersection formed by the plane cutting the bubbles.nThe equation was applied to machined plastic foams over a wide density range and the roughness factor (RB) caused by bubbles in the surface was shown to have values between 1 and 3. RB plotted against foam density gives a straight line. The contribution of the roughness of the solid material between the bubbles to the true surface area of the machined foams is not considered in this report.