Description

TAPPI TIP 0304-64 – How to Minimize Rolling Scores on Lightweight and High-Performance Liners in Diecutting Operations

This Technical Information Paper includes recommended operating procedures to minimize incidents of rolling scores on combined board in diecutting operations.

The ideal score must:
(1) crush the paper to produce a crease about which the board will fold or hinge
(2) produce relief for corrugated board or paper adjacent to the fold crease
(3) control the corrugated board deformation in the vicinity of the score to limit tension or shear in the paper.

The resultant score should be accomplished without cutting or cracking the paper of the combined board and should fold squarely along the centralized crease line. In order to achieve this, the scoring operation must be in good mechanical condition. This includes the following:
– Correct rolls, scores, and anvil diameters with correct total indicated runouts.
– Proper diameter of female anvil and correct OEM specified score width and height requirements.

Description

This Technical Information Paper includes recommended operating procedures to minimize incidents ofrolling scores on lightweight and high performance liners in both rotary and flat bed diecutting operations.The ideal score must:

(1) crush the paper to produce a crease about which the board will fold or hinge

(2) produce relief for corrugated board or paper adjacent to the fold crease

(3) control the corrugated board deformation in the vicinity of the score to limit tension or shear in the paper.

-Correct rolls, scores, and anvil diameters with correct total indicated runouts.

– Proper diameter of female anvil and correct OEM specified score width and height requirements.

High performance liners will give up moisture at a faster rate than a typical virgin liner produced with similar moisture content. High performance liners will release moisture more readily and heat up more quickly due to sheet densification (less air is trapped). The levels of preheater wrap typically used in the past will not work on high performance liners. The starch solids typically run are the 25-28% range to help improve bond in the high performance material to facilitate and insure efficient downstream operations without quality problems.