Checking the parallel of corrugating rolls with “NCR” paper, Technical Information Paper TIP 0304-62 (2014)
This TIP describes a procedure for checking the parallel of corrugating rolls in a single facer using NCR paper. The impressions made on the paper by the corrugating roll flute tips are then compared to evaluate parallelism.
Misaligned or out of parallel corrugator rolls can result in medium fracture, leaning flutes, and hi-lows. It can also reduce the “life” of corrugator rolls and the drive motor. The simplest method of checking the parallel of corrugator rolls is to use two copy “no carbon required” or NCR paper. Small narrow rolls are sold at most office supply stores for use in calculators or adding machines. Wider widths can usually be purchased from corrugating roll vendors. When fed through the corrugating rolls, the flute tips leave their impressions on the NCR paper where contact occurs.