Why is board stiffness testing and crease resistance testing important?

A printed sheet or roll of carton board is die-cut and creased into a preformed carton board blank.
This blank is then often glued and erected before being filled on an automated packaging line, these processes all interact mechanically with the blank to convert it into a three-dimensional object.

To be most cost-effective, it is important this conversion is performed at the maximum speed possible without causing misfeeds and blockages in the process.
It is also important that the finished material has the required dimensional strength to hold and protect the packaged product.

Board stiffness test and crease resistance testing are important parameters that help determine maximum conversion and packaging speeds, they can also be related to the final dimensional stability of the finished product.

Board stiffness is determined by the physical makeup of the substrate i.e. – its thickness, fibre mix, coating and manufacturing method. It is determined by measuring the resistance of a cut sample to a force applied through a pre-determined angle.

Crease resistance is a similar measure of resistance which is made across a preformed crease in the carton blank.