Dynamic Optical Displacement Calibration Protocols across Folding Boxboard Converting Lines
Dynamic blue-laser displacement calibration eliminates light-penetration drift, securing exact FBB crease metrics and stopping false sheet rejection.
Crease Profile Depth
Indentation Boundary
Converting quality specifications define the geometric vertical displacement imparted onto paperboard during die-cutting and creasing operations. High-speed folding box manufacture relies on this dimensional feature, where crease profile depth measures the distance between the uncreased board surface and the lowest point of the creasing channel groove. Standard benchtop optical profile gauges and contact depth micrometers capture this profile across the creasing channel.
The parameter applies strictly to the permanent deformation depth created by mechanical penetration, excluding elastic spring-back that occurs immediately after tool withdrawal.
Folding Performance
Folding resistance drops sharply when creasing depth establishes clean internal delamination lines across the board structure. Shallow creases leave internal fibre bonds intact, causing high cracking rates along outer linerboard surfaces during box squaring. Over-creasing cuts into face fibres and reduces packaging compression strength.
Tooling Geometry
Penetration force applied by the steel creasing rule forces target paperboard plies down into the elastic counter-crease groove. Board thickness, female channel width and male rule thickness together dictate the achievable depth of the groove profile without rupturing top liner fibres. Deep grooves promote localized shear stresses between middle plies, inducing controlled internal delamination necessary for clean ninety-degree carton folds.
Crease profile depth reaches stability once the creasing matrix material resists further compaction under repeated press impressions. Adjusting die-cutter platen pressure alters depth profiles directly across the full layout sheet.