Optimizing Creasing Rule Geometry for Coated Paperboard Packaging
Optimizing creasing rule tip radius and channel geometry enables controlled internal board delamination, eliminating coating cracking and springback jams.
Phenolic Resin Counterplate
Converting Subplate
Die-cutting and creasing operations in folding carton production use hard, dimensionally stable plates to support the sheet against the creasing rules. A phenolic resin counterplate is a custom-milled sheet of composite material that is bonded to the cutting plate to define the creasing grooves. This tooling provides a durable and precise alternative to manual creasing strips, ensuring sharp, clean creases over medium to long production runs.
Groove Milling
The grooves in the plate are cut using high-speed computer-controlled routers to match the layout of the creasing rules. The dimensions of these grooves must be matched to the board thickness to ensure the fibers are bent without cracking. This composite plate resists deformation under the repetitive pressure of the press, maintaining consistent crease geometry across the entire run.
If the counterplate is made from lower-grade materials, the grooves can round off, resulting in weak creases that fail on the packaging line.
Performance Control
Using these composite plates improves the speed of carton folding by ensuring that every crease is of equal depth. This consistency is vital for the correct operation of high-speed folder-gluers and cartoning machines. It minimizes waste and prevents the box from jamming during the erection process.