Theory of tack of pressure sensitive adhesive. I

If the tack of a pressure‐sensitive adhesive is closely related to the rolling motion of a ball on the material, it is more scientific to express tack in terms of the rolling friction coefficient, which depends on the physical properties of the materials, and not on any trivial conditions of measurements. It is shown that the rolling friction coefficient of a pressure‐sensitive adhesive can experimentally be determined from the pulling cylinder method much more easily than the rolling ball method and that we can theoretically calculate the rolling friction coefficient by making some assumptions, concerning deformation and failure of a pressure‐sensitive adhesive.