Читать книгу The Rheology Handbook - Thomas Mezger - Страница 236

At room temperature, the hot-melt adhesive at hand behaves like a flexible but tacky, soft solid. Placed in a flat cylindrical container, the adhesive is sticking to both its base and its top cover. Turning the cover manually with a constant force against the base causes the adhesive to resist at first, but then yielding slowly, showing creeping motion with increasing deformation until the cover reaches a twist angle of approximately 90° against the base of the container. When releasing the force on the cover, external forces are no longer acting on the adhesive and together with the cover it is turning back. This motion is faster at first, becoming slower and slower then, reaching finally the initial position again.