Oxbow Effect and Surface Temperature Profiles of Calender Rolls

Calender rolls distort on the ends where the paper is not acting as a heat sink. This can cause soft edges and cracks on the reel due to ends that have expanded more than the rest of the roll. Alternatively, the rolls can have hard edges when the ends of the rolls have been over-insulated and are of smaller diameter.

This presentation will go through the calculation procedure using finite element analysis to determine the shape of the calender roll currently in use. It gives examples of the calculated temperature and distortion profiles. The methods that can be used to reduce the amount of deformation are outlined. The discussion concludes with the measurement of a temperature profile through a calender stack, and the resulting thermal distortion.