Quasistatic theory of frost deformation in thermoplastic films

For the description of frost deformation in thermoplastic films, a quasistatic approach has been used. Considering equipotential and nonequipotential models, a relation between the spatial wavelength λ and the amplitude of the deformation is derived from the pressures in the equilibrium state. From this relation follows a predominant value of the frost wavelength to film thickness ratio λ/h. Reasonable agreement with the experimental results reported in the literature is obtained, i.e., the equipotential model is more appropriate, the predominant value of λ/h is approximately equal to π, and the frost can also occur if the surface potential is lower than the threshold value.