Total indicated runout and its impact on combined board quality, Technical Information Paper TIP 0304-56 (2022)
In the process of making corrugated board, there are several steps in the process that require precise applications of pressure between rolls, or consistent gaps between rolls in order to meter precise amounts of adhesive to the flutes. In order for these requirements to be met, rolls have to be parallel to each other and also must be as close to perfectly round as possible. Bearings or journals must also be operating in such a manner as to allow the rolls to turn as close to perfect circular motion as possible.