The scope below describes the Proposal for a New Standard with development in progress.
New standard for measuring hardness of the wound roll.
Method: Deceleration measurement with constant collision energy
Roll hardness measurement has been traditionally carried out in industries where products are formed into rolls. Roll hardness measurement is employed to gauge the roll uniformity. Baggy edges, gage bands, telescoping, staring, for example, are all issues that can be detected with proper roll hardness measurement systems. The variation in the hardness across the roll relates directly to converting issues.
The plunger is accelerated very precisely and repeatedly towards the roll surface with a known velocity. As soon as the plunger comes in contact with the surface of the roll, it begins to "decelerate". Once the velocity reaches 0, the results are calculated and reported in g-force or 1g = 9.81m/s. The rate of deceleration has a direct relationship to surface hardness.
If you would like to join the Working Group that is working on this new proposal, please write to standards@tappi.org