TAPPI TIP 0304-53 PDF

Singlefacer corrugator rolls are important components in the corrugating process. They produce the fluted medium which is the foundation on which the quality of corrugated board is based. If the condition of the corrugator rolls is allowed to deteriorate, board quality and corrugator productivity will deteriorate with it.
Corrugator rolls are hollow steel cylinders, with gear like teeth (or flutes) machined onto the surface. The entire surface is overlaid with a coating – often chrome or tungsten carbide – which protects the underlying steel flutes from wear. During the running life of a corrugator roll, wear caused by friction from the corrugating medium gradually wears away the roll coating, thus exposing the machined steel teeth underneath to wear. If the base metal is allowed to wear without recovering it with a fresh coating, a noticeable drop in flute height (caliper) will occur, and high-lows (a condition whereby flutes are not uniform height exiting the corrugators rolls) will become more pronounced. The corrugator roll will have to be recut, rebuilt to original specifications, or even scrapped.
A series of separate tests can determine current wear and help to track corrugating roll condition:
• Roll Surface inspection
• Flute depth---Use Tip 0304-75 for procedure
• Roll Diameter
• Coating Thickness