Creep - What is creep?
Definition of CREEP:
Also known as cold flow, creep is a type of material deformation that is defined as the tendency of a solid material to slowly move or deform under the influence of mechanical stress. Creep is a time-dependent deformation and accumulates as a result of long-term exposure to stress; the rate of creep is determined by the material’s properties, exposure time, exposure temperature, and the degree of stress that is applied to the material. Temperature is a particularly influential factor as virtually all materials will creep when approaching their melting point. This means that creep can occur at relatively low temperatures; for example, some plastics and metals (with low melting temperatures) will begin to creep at room temperature, while glacier flow is a result of creep in ice.
In labelling, creep can occur in any of the materials used to make labels, including adhesives, coatings, face materials, backing sheets, and printing inks. Creep is most commonly caused by label materials being exposed to too much heat and/or pressure at any point throughout the manufacturing and printing processes, during storage, or after a label has been applied to a substrate. It is particularly problematic when dealing with label adhesives, as creep will result in an adhesive moving outside of its own layer within a label construction, which can result in blocking (surface to surface sticking between sheets or rolls of labels), deformation or discolouration in adjacent layers, can damage printers, and can ultimately prevent a label from successfully adhering to a substrate. When creep occurs in an adhesive it is commonly referred to as adhesive bleed or adhesive ooze.Go Back to Glossary