Dynamic Fracture Mechanics of Multi Layer Paperboard Creasing under Rapid Shear Loading
Rapid shear creasing requires tailored interply delamination toughness to prevent liner fracturing while reducing folding torque on high-speed lines.
Score Rupture Allowance
Folding Resistance
The maximum force or elongation that a creased paperboard can withstand before its outer fibers crack governs the structural integrity of a folded carton. The score rupture allowance represents the limit of deformation a creased line can undergo during high-speed assembly. It ensures that the folding carton maintains its aesthetic appeal and strength.
This parameter is measured using standardized crease-bend test methods.
Converting Impact
High-speed filling lines require boards that do not split when the carton flaps are folded and glued. If the score rupture allowance of the board is too low, the packaging will fail on the line, causing machine downtime and product waste. During the converting process, the score must be deep enough to facilitate easy folding but not so deep that it damages the paper fibers.
The correct balance allows the carton to be erected smoothly at speeds of several hundred units per minute. Inadequate score line performance leads to rejects and lost productivity.
Fiber Quality
Fiber length and moisture content of the board determine this mechanical allowance. Long softwood fibers and high humidity increase the elasticity of the board, allowing for a higher score rupture allowance. Dry board or recycled fibers with shorter lengths are more brittle and prone to cracking.