Crown height is the difference between the diameter of the roller center and the diameter of near the roller end (Generally 50 mm from the end)
The purposes of giving crown to rollers are:
a. Correction of the roller deflection during operation. (Uniform contact)
b. Making the most appropriate flow of the substrate such as cloth, plate and paper. (To avoid meandering)
It is better to give crown especially to the following rollers.
- The value of L/D (roller length / roller diameter) is relatively big.
- The pressure of the roller is relatively big.
Crown precision is influenced by factors such as the roller length, the roller diameter, the rubber type, the rubber thickness, the finish condition, the crown volume and the rubber hardness. The crown precision of Katsura is within 5/100 mm (the tolerance between the diameters of 2 symmetrical points of the roller.)