VERFAHREN ZUR HERSTELLUNG VON ABREISSBAREN BÖGEN

摘要

The present invention relates to a method of manufacturing tearable sheets, wherewith each sheet obtains a perfectly smooth tear edge when torn-off. The method comprises the steps of: punching each sheet transversely of the fibers of said sheet from a first side of the sheet to an extend corresponding to a firs portion of the thickness of the sheet; and punching each sheet transversely of the fibers of said sheet from a second side of the sheet to an extent corresponding to a second portion of the thickness of said sheet; wherein the sum of said first thickness portion and said second thickness portion is smaller than the thickness of the sheet, and wherein the second punching operation is performed parallel with the first punching operation but displaced in a plane parallel with said first and said second sides of the sheet, said displacement being adapted for tear-off purposes.