Multi-Layer Coating Board Production: Equipment for Premium White Board | Leizhan
The Recipe for Premium Coating Board
The best coating formulation in the world cannot fix a poorly formed base sheet. Here is what Leizhan recommends for a 200-400 TPD multi-layer coating board line.
Multi-Layer Forming — The Foundation
Coating board (Folding Box Board / White Liner Board) typically requires 3-5 layers. Each layer has a specific function and fiber recipe:
- Top layer: Bleached kraft pulp (60-90 gsm), brightness 82-88% ISO
- Under-top: Mixed bleached pulp (30-50 gsm)
- Middle/Filler: OCC or DIP (150-300 gsm), lowest cost layer
- Back layer: Unbleached kraft or OCC (50-80 gsm), for bending stiffness
Key Equipment for Each Layer
Top Layer Preparation — Bleached Pulp Refining
The top layer determines printability and appearance. Leizhan double disc refiners (DD refiner) operate at 4-5% consistency with 30-50 kWh/t specific energy, targeting 28-35 SR freeness. Disc diameter: 500-660 mm, motor: 132-250 kW.
Middle Layer — Recycled Fiber Processing
The middle layer represents 50-65% of total board weight and is your biggest cost lever. A proper OCC pulping line with drum pulper and pressure screens produces middle layer stock at $180-250 per ton versus $500-700 for virgin fiber. Leizhan systems handle 200-500 TPD for the middle layer alone.
Screening and Cleaning for Coating Base Stock
Coating board demands cleaner stock than liner or corrugating medium. We recommend:
- Top layer: 0.12-0.15 mm fine slotted screen + forward cleaner (4-5 stage)
- Under-top: 0.15-0.20 mm slotted screen + forward cleaner (3-4 stage)
- Middle: 0.20-0.35 mm slotted screen with rejects to secondary stage
- Back: 0.25-0.40 mm slotted screen
Motor power for screening: 45-90 kW per screen position. Typical accepts consistency: 0.8-1.5%.
Energy and Cost Breakdown
Here is what a 300 TPD coating board line consumes:
- Stock preparation (all layers): 55-85 kWh/t
- Paper machine (Fourdrinier/multi-ply): 120-180 kWh/t
- Coating kitchen and application: 60-90 kWh/t
- Calendar and reel: 30-50 kWh/t
- Total: 265-405 kWh per ton of finished board
Maintenance Tips for Coating Board Lines
- DD refiner plates: Replace every 3-5 months. Worn plates increase energy 15-25% for same freeness and cause fiber cutting.
- Fine screen baskets: Inspect slot width monthly. 0.02 mm widening allows stickies breakthrough that causes coating defects.
- Coating filters: Change every 4-6 hours during coating runs. Plugged filters create streaks that ruin entire reels.
- Press felt conditioning: High-pressure showers at 20-25 bar, continuous oscillation. Poor felt condition affects coating holdout.
Leizhan Coating Board Solutions
At Leizhan Technology, we provide complete stock preparation systems for multi-layer coating board production from 100 to 600 TPD. Whether you are producing folding box board, white liner, or coated duplex board, we engineer the pulping, screening, and refining equipment to match your specific layer requirements.
Ready to upgrade your coating board production? Email leizhanequipment@gmail.com. Share your daily tonnage and board grades — we will design a custom stock preparation solution within 48 hours.