Corrugated Box Slotter Knives

Corrugated Box Slotter Knives

Persistools corrugated box slotter knives are precision cutting tools used in corrugated converting equipment to form the slots between carton flaps before folding, gluing, or closing.

After corrugated board has been printed, scored, and cut to the required dimensions, the slotting section removes narrow sections of material between adjacent flaps.

These slots allow the upper and lower carton flaps to fold independently and form the final box structure.

Typical applications include:

• Corrugated box production
• Carton converting
• Flexo printing and slotting lines
• Folder-gluer systems
• Corrugated board finishing
• Packaging box manufacturing

Upper and Bottom Slotter Knife System

A complete slotting position normally uses an upper slotter knife and a corresponding bottom slotter knife.

Upper Slotter Knife

The upper knife is commonly manufactured in a segmented or sector-shaped form.

During machine rotation, the upper knife enters the corresponding cutting area of the lower knife and removes the material required to form the flap slot.

The upper knife is responsible for the main cutting action and therefore requires:

• Sharp cutting edges
• Good toughness
• Stable geometry
• Accurate mounting dimensions
• Consistent cutting profile

Bottom Slotter Knife

The bottom knife is generally circular or assembled from semicircular sections around the lower shaft.

It provides the mating cutting position and mechanical support required for the upper knife to complete the slotting action.

Accurate matching between the upper and bottom knife is important for:

• Clean slot edges
• Stable cutting depth
• Reduced tearing
• Consistent slot width
• Reduced knife collision
• Longer service life

HSS Construction for Tough, Repeated Cutting

Corrugated slotter knives are commonly manufactured from high-speed steel or selected tool steels.

Compared with very hard but brittle cutting materials, HSS provides a practical balance of:

• Cutting-edge sharpness
• Impact resistance
• Toughness
• Wear resistance
• Regrindability

This is important because slotting knives repeatedly enter and leave the cutting position during high-speed machine rotation.

Machine-Specific Designs

Unlike simple standard circular knives, corrugated slotter knives are often closely related to the machine structure.

Different converting machines may use different:

• Knife diameters
• Segment radii
• Mounting-hole patterns
• Knife thicknesses
• Slot widths
• Upper/lower knife combinations
• Cutting profiles
• Shaft diameters

For this reason, replacement knives are commonly manufactured according to:

• Machine brand
• Machine model
• Original knife dimensions
• Customer drawing
• Existing blade sample

Upper and bottom slotter knives can be supplied separately or as matched sets.