Slitter Scorer and Cut-Off Systems: Equipment Guide for Corrugating Lines

The slitter scorer and cut-off are the final processing stations on a corrugating line. They convert continuous board web into finished sheets at specified widths and lengths. Accuracy here directly affects downstream converting efficiency.

Slitter Scorer Function:

The slitter scorer performs two operations simultaneously:

1. Slitting — Cuts board to specified width (multiple widths possible)

2. Scoring — Creates fold lines for box manufacturing

Slitting Methods:

Sharp Slitter (Shear Cut):

• Two blades shear against each other

• Clean cut edge, minimal dust

• Preferred for high-quality board

• Blade life: 8-24 hours depending on board weight

Score-Cut Slitter:

• Single blade partially cuts through board

• Faster blade change, lower cost

• More dust generation

• Common on mid-speed lines

Tungsten Carbide Slitters:

• Longer blade life (3-5x standard steel)

• Higher initial cost, lower per-meter cutting cost

• Recommended for high-volume operations

Scoring Methods:

Linear Scoring:

• Score wheel creates straight crease line

• Most common method

• Score depth adjustable for board weight

• Too deep: Board cracks; Too shallow: Poor folding

Offset Scoring:

• Score line offset from slit edge

• Used for specific box designs

• Requires precise positioning

Reverse Score (Inside Score):

• Score from liner side

• For visible outside printing applications

• Requires specialized score heads

Cut-Off Machine Function:

The cut-off cuts the continuous web into individual sheets at programmed lengths.

Types of Cut-Off Systems:

Rotary Cut-Off:

• Rotating blade cuts against anvil roll

• High speed capability (up to 350 m/min)

• Standard on modern corrugating lines

• Cut accuracy: ±2mm typical

Flying Shear Cut-Off:

• Blade travels with web during cut

• Enables cutting at full line speed

• Required for speeds above 250 m/min

• More complex, higher maintenance

Guillotine Cut-Off:

• Vertical blade descends on stationary web

• Line must stop or slow for each cut

• Found on older or low-speed lines

• Simple but limits production speed

Key Specifications:

Working Width: Must match corrugating line (1400-2800mm)

Number of Slits: 1-5 simultaneous widths typical

Cut Length Range: 500-5000mm typical

Cut Accuracy: ±1-3mm depending on system

Speed Rating: Must match or exceed line speed

Setup and Changeover:

Order Change Procedure:

1. Input new sheet width and length in control system

2. Position slitter blades to new width settings

3. Adjust score heads to new positions and depths

4. Set cut-off length program

5. Run test sheets and verify dimensions

6. Adjust trim width if needed

Typical changeover time: 5-15 minutes for experienced operators

Maintenance Schedule:

Daily:

• Inspect slitter blade condition

• Check score wheel wear

• Clean debris from slitter section

• Verify cut length accuracy with sample sheets

Weekly:

• Replace worn slitter blades

• Lubricate moving parts

• Check belt tensions on cut-off drive

• Calibrate encoder and length measurement

Monthly:

• Inspect anvil roll condition (rotary cut-off)

• Check hydraulic/pneumatic systems

• Review cut accuracy statistics

• Replace score wheels as needed

Common Quality Issues:

Ragged Slit Edge:

• Dull blades, wrong blade type, excessive speed

• Solution: Replace blades, reduce speed, check blade alignment

Incorrect Sheet Length:

• Encoder drift, web slippage, worn drive rolls

• Solution: Recalibrate encoder, check web tension, inspect rolls

Poor Score Quality:

• Wrong score depth, worn score wheel, incorrect board moisture

• Solution: Adjust depth, replace wheel, check paper moisture

Dust Accumulation:

• Normal byproduct of slitting — requires dust extraction system

• Inadequate extraction causes quality and safety issues

• Maintain dust collection filters and ductwork

Integration with Stacker:

Slitter scorer and cut-off must coordinate with the stacker:

• Sheet count per stack programmed in cut-off

• Stacker receives signal for each sheet

• Misalignment causes miscounted stacks and delivery errors

• Modern lines use PLC integration for seamless coordination

Contact Xuegong for corrugating line configuration advice including slitter scorer and cut-off specifications.