Creasing Rule Selection for Coated Folding Boxboard Conversion
Selecting steel creasing rules and matrix channels for coated FBB requires matching board caliper and CTMP core shear limits to prevent surface cracking.
CNC Steel Counter Plate
Die Tool
Computer-controlled milling machines carve dedicated score channels into hardened steel sheets to form rigid counter dies for long-run carton conversion. Machined steel plates replace phenolic or paperboard counter materials on high-speed flatbed die cutters. A CNC steel counter plate aligns female creasing grooves directly opposite male steel rules set into cutting dies.
Precise groove geometry ensures consistent crease formation across millions of packaging blanks without channel wall degradation. Milling tools cut channels to exact depth and width tolerances corresponding to specific board caliper and crease geometry requirements. This tooling category governs folding boxboard creasing on high-volume runs and stops applying when converting corrugated fluting or low-volume custom packaging.
Milling Precision
Machining tolerances on steel counter tooling remain within five micrometers across the entire plate surface. Numerical control programs drive carbide end mills along precise vector paths derived from structural CAD drawings. Channel bottoms receive polished finishes to prevent paperboard drag during feeding operations.
Impression Durability
Hardened alloy construction prevents channel deformation under high compression loads experienced during continuous die cutting. Steel channels resist abrasive wear from board dust and fiber fragments over production runs exceeding five hundred thousand impressions. Phenolic counter channels degrade through shoulder rounded wear after shorter production intervals, altering crease geometry over time.
Boxboard converted with steel plates maintains consistent crease folding resistance from initial setup through final run completion.