Influential behavior of a Nipcorect roll on the paper thickness grass direction profile in the softcalender

Since the demonstration of the influential behavior of a Nipcorect Roll at the APV 1994 in Graz, which was based exclusively on calculations at the time, certain practical results have been made available. The correction potential of the Nipcorect Roll predicted as a result of those calculations has been confirmed for all applications indicating that this potential represents a substitute for external components such as inductive heating systems or air jets. In addition to the presentation of practical results from certain installations, the construction of Nipcorect Rolls and related periphery receive closer scrutiny, in particular the correction potential where a conventional roll jacket (plastic-coated cast iron) is used with respect to reaction values and flute length. It is shown that the flexibility of the roll jacket, which is substantially dependent on wall thickness, together with the zone width in effect contributes decisively to the influenceable paper flute length. The zone width to wall thickness ratio must not fall below a certain value if economical operating behavior is to be guaranteed. With regard to the utilization of fully elastic, fibre-reinforced plastic roll jackets, which permit further reduction of zone widths, the results from a testing facility are demonstrated. In this testing facility profile corrections with a flute length of 55 mm are possible at a width of 600 mm. Fine profiling, not possible in the supercalender, is demonstrated under consistent application of the Nipcorect Roll in the Janus Calender.