Chemical Migration Test Protocols for Modified Dispersion Coated Packaging
Chemical migration testing for dispersion coated board requires single-sided extraction cells and post-crease migration proofs to account for score-line breaks.
Creasing Rule Mechanics
Indentation Depth
Die-cutting tooling components apply concentrated compressive force to fracture internal paperboard bonds without severing surface liners. Analysis of creasing rule mechanics evaluates how steel rule profiles force paperboard into female matrix channels to create clean scorelines. The process forces middle board plies to delaminate while the outer liner stretches without cracking.
Improper depth configuration causes liner tearing or insufficient fold relaxation.
Delamination Control
Penetration of the steel rule creates a localized shear zone that forces internal fiber plies to separate into distinct layers. Effective creasing rule mechanics requires matching rule width and matrix groove dimensions to substrate thickness. Excessive penetration cuts the top liner fibers, whereas insufficient penetration leaves the board stiff and resistant to folding.
Dynamic load cells inside die-cutting presses monitor peak impression force during high-speed converting. Machine operators adjust press impression in increments of hundredths of a millimeter to establish optimal ply separation. The delaminated zone acts as a micro-hinge that lowers bending resistance during carton erection.
Board stiffness and moisture content determine the precise impression force required for uniform creasing.
Tooling Geometry
Steel rule edge profiles range from full round to flat chamfered edges depending on board caliper and coating type. Correct application of creasing rule mechanics prevents scoreline cracking on heavy clay-coated folding boxboards. Matrix channel width must equal board thickness plus twice the rule thickness to prevent shearing.
Quality control labs inspect cross-section cuts of creased board to verify internal layer separation.