Roll hardness is a roll feature that indicates the equality of the thickness profile and tension in a roll. In most cases, a relationship exists...

Roll hardness is a roll feature that indicates the equality of the thickness profile and tension in a roll. In most cases, a relationship exists between the roll hardness and roll density. The higher the hardness value of a roll, the denser it is. Roll hardness measurements are widely used in the paper and plastic industries. Roll tightness and roll hardness terms are commonly used interchangeably in the paper industry.

Almost any material that must be wound into a roll can be controlled and measured for roll hardness.

In contrast to the thickness profile measurement, which measures the one wrap of the film only, the thickness equality obtained from measuring the roll hardness profile takes into account many thousands of wraps. Winding cannot make paper better, but in many cases the product quality can be much lower after winding, hence the correct control of roll profile hardness is one of the most important roll parameters.