Pressure Inside a Paper Roll

Hello UoDChemE02,

For most applications, you want the pressure at the core and the outside of the roll to be the same. This is achieved by a tension taper function as the roll is wound. Some winders use torque to achieve a "natural" taper. In more precision winding, the amount of taper is determined using feedback from the load cells with an algorithm. If you do not decrease the tension enough as you are winding the roll, the pressure at the core will increase with successive winds and you may crush the core.

This is extremely difficult to calculate because, not only do you have tension to take into account, but the friction of the web material to itself and it's elasticity.

If your winder has a taper function that can be adjusted, the best solution I can see would be to generate some data by running some trials. The tension in these rolls can be measured using pressure-sensitive films. See the following sources (disclaimer):

http://www.sensorprod.com/index.php

http://www.tekscan.com/pressure-indicating-film.html?gclid=CNvJz-aXh6ICFVbE3AodNH0eUA

Using the data from these trials, adjust the taper function parameters accordingly.

Let me know if I can elaborate on anything.

Mike