Designing Counter Die Relief Profiles for Laminated Folding Boxboard
Counter die relief profiles for film laminated folding boxboard require expanding channel widths by twenty percent to prevent outer film shear tearing.
Creasing Moment
Mechanical Resistance
Physical force measured in newton-millimeters describes the torque required to fold paper or paperboard along a defined line. The creasing moment represents the opposition a substrate offers to a rotary creasing rule as it displaces fibers to form a hinge. High values denote stiff or thick stocks that necessitate greater pressure during the conversion process to prevent cracking or uncontrolled folding.
Low values allow for easier folding but risk insufficient fiber compression and poor hinge definition.
Production Variables
Board composition influences the level of energy required to deform the sheet during the folding operation. Recycled fibers often produce different force profiles compared to virgin pulp due to variations in moisture absorption and internal bonding strength. Caliper adjustments also alter the load required, as thicker sheets naturally increase the distance from the neutral axis during the bend.
Lubrication of the creasing channel sometimes reduces friction, though the underlying substrate resistance remains a function of internal stiffness and structural density.
Application Tolerance
Automated packaging lines require consistent folding force to maintain high speeds without causing jams or irregular package geometry. Excessive variation leads to cartons that fail to sit square or exhibit resistance that exceeds the capacity of the folding machinery. Quality control departments verify this parameter to ensure that every batch performs within the specified threshold of the converting equipment.
Stable folding behavior reduces mechanical wear on equipment parts and guarantees structural integrity for the finished product.