Kraft Liner Paper Making Line: Complete Pulping to Paper Machine Solution
Kraft Liner Paper Making Line Overview
Kraft linerboard is the primary packaging material for corrugated containers, requiring high burst strength, excellent ring crush resistance, and consistent surface quality. A well-engineered kraft liner production line integrates pulping, screening, refining, and paper machine sections to achieve production capacities ranging from 200 to 800 TPD with basis weights of 100–300 gsm.
The complete kraft liner making line begins with waste paper or virgin pulp processing and extends through the wet end, press section, drying, and finishing. Key equipment includes hydraulic pulpers for efficient defibering, pressure screens for contaminant removal, double disc refiners for fiber development, and fourdrinier or gap former paper machines optimized for heavy-weight liner grades.
Key Equipment Specifications
- Hydraulic Pulper: Capacity 200–600 TPD, operating consistency 4–6%, motor power 132–500 kW. Designed for continuous operation with rotor extraction plate for tramp material removal.
- Pressure Screen (Primary): Screen basket with 0.20–0.35 mm slots, maximum feed consistency 3.5%, reject rate below 15%. Fiber recovery exceeds 95% with minimal fiber loss.
- Double Disc Refiner: Disc diameter options 660/910/1100 mm, motor 250–900 kW, refining consistency 3.5–5%. Energy savings of 15–20% compared to conventional conical refiners.
- Fourdrinier Paper Machine: Wire width 3200–5600 mm, design speed 300–600 m/min, basis weight range 100–300 gsm, daily output 200–500 TPD.
Energy Consumption and Cost Analysis
For a 400 TPD kraft liner production line, the typical energy consumption breakdown is as follows: pulping section 18–22 kWh per ton of pulp, screening and cleaning 8–12 kWh/t, refining 40–60 kWh/t (depending on target freeness), and paper machine drive 80–100 kWh/t. Total electrical consumption ranges from 150–200 kWh per ton of finished linerboard. Steam consumption in the drying section averages 1.8–2.2 tons of steam per ton of paper at 3–5 bar pressure.
Optimizing the refining process can reduce total energy by 12–18%, translating to annual electricity savings of approximately USD 45,000–65,000 for a mid-scale mill. Variable frequency drives on pumps and agitators contribute an additional 8–10% reduction in auxiliary power consumption.
Preventive Maintenance Guidelines
- Pulper rotor and screen plate: Inspect every 3 months for wear. Replace screen plate when hole diameter increases by more than 15% from original specification.
- Pressure screen basket: Check slot dimensions quarterly. Replace basket when slot width exceeds 0.05 mm beyond nominal — wider slots reduce screening efficiency and increase stickies carryover.
- Refiner plates: Monitor refining energy vs. freeness drop. Replace plates when energy consumption increases by 20% at the same freeness target, typically every 8–12 months under normal operation.
- Paper machine clothing: Forming fabric life 45–60 days, press felt life 30–45 days, dryer fabric life 12–18 months. Track water removal efficiency to optimize replacement intervals.
Turnkey Kraft Liner Solutions
Zhengzhou Leizhan Technology supplies complete kraft liner paper making lines including raw material handling, stock preparation, approach flow, paper machine, and auxiliary systems. Equipment is designed for 24/7 continuous operation with proven reliability in mills across 50+ countries.
For technical consultation and detailed equipment specifications, contact our engineering team at leizhanzhang@gmail.com or visit www.pulprefining.com.