In order to clarify the process of snow accretion, which occurs at a temperature below the melting point of ice, experimental studies were made on the microscopic process of ice Adhesion as well as the tensile adhesive strength of snow onto various kinds of materials.
For this purpose, direct observations were made of the formation of an ice bond developed at the interface between an ice particle and a plate made of a transparent material such as glass, acrylic plastic (polymethyl methacrylate (PMMA)), or ice, and measurements made of the growth rate of the real contact area.
The growth rate of an ice bond formed at the interface between an ice particle and the plate of a hydrophilic material such as glass was equal to or slightly larger than that of ice sintering, while an ice bond was not formed at the interface between an ice particle and the plate of a hydrophobic material such as teflon.
As for adhesive strength, with the lapse of time it increased rapidly at the former interface and slowly at the latter interface. Examinations of fracture planes revealed that at or near the interface a pure adhesive break did not take place with the exception of teflon and vinyl, and that what took place there was a cohesive break or a mixture of cohesive and adhesive breaks.