Creasing is an operation which facilitates the folding operation. During this process, the paperboard is weakened along well defined folding lines, which then act as hinges for folding packaging and graphical products. Without creasing the surface, plies will crack and/or the folding line will be undefined preventing a neat and clean fold. This folding process is carried out using a steel ridge on the die with a round smooth edge and an accurately cut groove in the mirrored anvil to the cutting die (sometimes referred to as the counter-doe). The rule pushes the paperboard into the groove located under the paperboard, creating a permanent crease. The tool’s construction and performance are essential elements in obtaining a satisfactory result.
Example of a good crease
Example of a bad crease
The quality is highly dependent upon die setup, integrity of die registration, and die wear. In order to achieve satisfactory creasing or embossing, a die set must be prepared and set-up to meet specifications. Dies can feature specially designed segments and removable rings to accommodate a wide variety of ways while enabling selective repair of high wear areas.