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.
Bevel Profile
Edge geometry
Cartonboard converting relies on controlled board separation where a bevel profile determines the exact angular geometry sliced into folding boxboard edges during the die cutting operation. Slitting blades strike the substrate at precise inclinations ranging between thirty and sixty degrees to prevent fiber crushing while generating clean parting lines. Folding cartons carrying cosmetic products require sharp angular relief along glue flaps to ensure square box erection on high speed filling lines without board delamination.
Rotary cutters demand exact blade adjustments because angular deviations alter caliper compression ratios across the converted sheet.
Fiber separation
Substrate integrity depends entirely upon how cleanly steel rules divide compressed cellulose networks during the creasing and cutting phase. Board thickness dictates the required angular offset because heavy folding boxboard demands wider relief angles than lightweight linerboard used in corrugated packaging. Dull cutting knives generate excessive friction, causing microscopic surface tearing that weakens structural corners during subsequent gluing sequences.
Proper angular grinding prevents micro-dust accumulation on press rooms by eliminating loose fiber shedding during high speed converting operations.
Crease interference
Finished packaging performance relies on managing the physical interaction between adjacent score lines and angled board edges during automatic box closure. Excessively steep angular cuts reduce glued joint surface area by altering the physical footprint available for cold glue application. Packaging engineers calculate maximum permissible slitting angles to guarantee that erected cartons withstand stacking loads without failing along trimmed boundaries.
Proper angular alignment ensures reliable adhesive penetration into exposed paper fibers without squeezing liquid polymers out of joint interfaces.