Rotary Die Scoring Stress Wave Signal Acquisition
Real-time acoustic stress wave monitoring on rotary die scoring lines detects paperboard matrix micro-cracking instantaneously, reducing convert scrap by up to 80 percent.
Counter Matrix Alignment
Mechanical Coincidence
Creasing board requires precise coordination between the creasing rule and the grooved creasing matrix attached to the cutting plate. When this relationship is correctly established, counter matrix alignment ensures that the score lines run straight, prevent liner cracking, and yield clean folding edges on the converted folding carton. Misalignment of these parts produces asymmetric creases that rupture the outer board fibers during folding.
Registration Integrity
Platen presses use mechanical lockups to hold the cutting die and counter plate in position. Over long production runs, temperature shifts and mechanical vibration can cause minute shifts in the position of the matrix relative to the steel rule. This shift creates unequal shoulders on the crease, which reduces the carton’s top-to-bottom compression strength.
Press operators test this condition using pressure-sensitive films or test blanks to verify that the pressure is evenly distributed across both shoulders. Correcting this before run start-up is essential.
Converting Tolerance
The permissible tolerance for this positioning is usually under one tenth of a millimeter to maintain folding quality on high-speed gluer-folders. Heavy folding boxboard grades need more clearance than thin paperboards, as thicker boards have larger fiber volumes that must migrate into the crease bead. If the matrix shifts too far, the carton will fail on automated packing lines because the panels cannot fold to the specified ninety-degree angle.