Depending on the desired effect, the roller surface can be polished, matted or a pattern can be engraved. In addition, double-wall roller systems providing the possibility of heating or cooling are available. The pressure is generatred hydraulically or pneumatically via lever systems, depending on the required pressing force. From simple pressing units with a linear pressure of 25 N/mm up to high-capacity textile calenders with more than 250 N/mm are usual. Special provisions have to be made for the roller design in order to compensate the bending due to pressure generation and thermal deformation. Depending on the profile of requirements three different roller types are available:
- Flexible roller with crowing
- The so-called centre-supported rollers
- Rollers with adjustable pressure
- Equal pressing force across the complete working width
- Stable and long-lasting design