Stacker and Board Delivery Systems: Corrugating Line End Section Guide

The stacker is the final machine on a corrugating line. It receives cut sheets from the cut-off, organizes them into neat stacks, and prepares them for downstream converting or shipping. A well-configured stacker maximizes line efficiency and protects board quality.

Stacker Functions:

1. Receive individual sheets from cut-off at line speed

2. Count sheets per stack (programmable)

3. Align and square each stack

4. Compress stacks for stability

5. Discharge stacks to conveyor or bundling system

6. Handle multiple widths simultaneously (multi-cut lines)

Types of Stackers:

Counter-Stacker (Most Common):

• Sheets counted and dropped onto accumulating platform

• Platform lowers as stack grows

• When count reached, full stack discharged laterally

• Speed: Up to 350 sheets/min

• Standard on most corrugating lines

Belt-Stacker:

• Sheets conveyed onto stacking belts

• Belts jog sheets into alignment

• Gentler handling for lightweight or printed board

• Better for high-quality liner surfaces

Bypass Stacker:

• Can divert sheets to bypass stacking

• Used when connecting inline to converting equipment

• Sheets flow directly to FFG without stacking

• Essential for inline corrugator-to-FFG configurations

Multi-Stacker (Multi-Cut Lines):

• Separate stacking stations for each width

• Slitter scorer cuts 2-3 widths simultaneously

• Each width stacked independently

• Improves efficiency for multi-order production

Key Specifications:

Stacking Speed: Must match or exceed cut-off speed

Max Sheet Size: Match line working width and cut length

Max Stack Height: 800-1500mm typical

Sheets Per Stack: Programmable, typically 20-50 sheets

Number of Stacks: 1-3 simultaneous (multi-cut)

Stack Accuracy: ±2mm alignment tolerance

Board Quality Protection:

The stacker is the last point where board quality can be affected before converting:

• Gentle sheet handling prevents edge damage

• Proper alignment avoids dog-eared corners

• Controlled stacking pressure prevents board crush

• Adequate support prevents bottom sheet bowing

• Anti-static systems prevent sheet misfeeding

Bundle and Delivery Systems:

After stacking, boards typically go through:

Strapping/Bundling:

• Plastic strap or band applied around stack

• Secures stack for handling and transport

• Automatic or semi-automatic systems

• Cross-strapping for tall stacks

Conveyor Delivery:

• Belt conveyors transport stacks to warehouse or converting area

• Right-angle transfers for space-efficient layouts

• Automatic routing to different destinations by order

Forklift Loading:

• Stacks placed on pallets for forklift handling

• Automatic pallet dispensers and loaders available

• Standard pallet size: 1200×1000mm or regional equivalents

Waste Handling Integration:

The stacker area also manages edge trim waste:

• Trim chutes collect edge waste from slitter scorer

• Pneumatic or belt conveyors transport trim to baler

• Automatic baling systems compress waste for recycling

• Proper waste removal prevents accumulation and fire risk

Stacker Maintenance:

Daily:

• Check sheet counting accuracy

• Inspect stacking platform condition

• Clean dust and debris from stacking area

• Verify discharge mechanism operation

Weekly:

• Lubricate lift mechanism and guides

• Check belt conditions on belt-stackers

• Inspect squaring paddles and alignment devices

• Calibrate sheet counter

Common Problems:

Miscounted Stacks:

• Sensor misalignment or dust on counting sensors

• Sheet double-feeding from cut-off

• Solution: Clean sensors, check cut-off timing

Poor Stack Alignment:

• Worn squaring paddles, uneven stacking platform

• Solution: Replace wear parts, level platform

Sheet Damage at Stack:

• Excessive drop height, worn impact surfaces

• Solution: Adjust platform lowering speed, replace padding

Stack Discharge Jams:

• Misaligned discharge conveyor, stack too tall

• Solution: Align discharge, reduce sheets per stack

Integration with Downstream Equipment:

Offline Converting: Stacks conveyed to warehouse, then manually loaded to FFG

Inline Converting: Bypass stacker feeds sheets directly to printer slotter or FFG

Pre-Print Lines: Stacks may feed to laminating station for printed sheet application

Contact Xuegong for corrugating line configuration including stacker and delivery systems.