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Coating Formulation and Application Technology for High-Qual...
Coating Board Production Technology Coating board production combines multi-layer forming with precision coating application. The process requires careful control of fiber composition, formation uniformity, and coating formulation to achieve the surface quality demanded by packaging converters. Multi-Layer Forming Configuration Top Liner: Bleached kraft pulp, 25-40 g/m2, high brightness for print surface Middle Layer: Mechanical pulp or deinked pulp, provides bulk and stiffness Back Liner: Unbleached kraft or recycled fiber, 25-40 g/m2 Coating Layers: Pre-coating (10-15 g/m2) + top coating (8-12 g/m2) per side Equipment Specifications Headbox: Multi-layer with 3-4 channels, slice opening 12-18mm Fourdrinier: 25-30m wire length with dewatering elements Press Section: 3-nip, 80-150 kN/m, dryness target 46-48% Dryer Section: 36-48 cylinders, 1800mm, 4-5 steam groups Coating Station: Blade or air knife, 400-800 m/min Calender: 2-4 nips, heated rolls for surface finish Energy Data Steam: 1.8-2.2 tons/ton paper Electric power: 350-450 kWh/ton Coating drying: 30-40% of total energy Maintenance Intervals Daily: Doctor blade contact check, coating blade inspection, dryer surface monitoring Weekly: Wire/felt tracking, steam trap verification, coating preparation system cleaning Monthly: Coating blade replacement (or when streaks appear), calender roll surface inspection Quarterly: Full dryer inspection, press roll cover check, coating circulation system flush Contact us for coating board...
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Fine Screening and Cleaning Systems for Premium Cultural Pap...
Cultural Paper Production: Deinking and Refining Technology Premium cultural paper production requires advanced deinking systems and precise refining control. Writing paper, copy paper, and offset grades demand high brightness, uniform formation, and controlled surface properties. Deinking System Equipment High-Consistency Pulper: 14-18%, 40-50°C, chemical dosing for ink detachment Coarse Screening: 2.0-3.0mm holes for large contaminant removal Fine Screening: 0.15-0.25mm slots for small particles Flotation Deinking: Multi-stage cells, 0.8-1.2% consistency, 85-95% ink removal Dispersion: 80-95°C, 25-30% consistency for residual ink particle reduction Post-Flotation: 0.8-1.0% for final specks removal Disc Thickener: Concentrates to 8-12% before machine chest Refining Parameters by Grade Copy Paper (70-80 gsm): Target 35-40 °SR, SEL 1.0-1.5 J/m Offset (60-100 gsm): Target 38-45 °SR, SEL 1.2-1.8 J/m Writing/Bond (80-120 gsm): Target 40-48 °SR, SEL 1.5-2.0 J/m Energy Consumption Deinking system: 200-300 kWh/ton (flotation + dispersion + cleaning) Refining: 80-180 kWh/ton for 30-45 °SR increase Paper machine: 280-350 kWh/ton Maintenance Schedule Daily: Check flotation cell air flow, verify chemical dosing rates, monitor brightness Weekly: Inspect screen baskets, check refiner plate gap, verify disc thickener filtrate clarity Monthly: Calibrate brightness meter, check disperser disc wear, clean flotation cells Quarterly: Refiner plate inspection, screen basket replacement if slots widened >15% Contact us for...
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Kraft Liner Paper Production: How to Reduce Energy Consumpti...
Kraft Liner Production: Equipment and Process Overview Kraft linerboard production from recycled fiber requires a carefully integrated stock preparation and paper machine system. The process converts OCC (old corrugated containers) and kraft cuttings into high-strength linerboard suitable for corrugated box manufacturing. Key Equipment Specifications A complete kraft liner production line rated at 300-600 TPD includes the following major equipment: Hydraulic Pulper: D-type design, 132-500 kW motor, pulping consistency 4-6%, batch time 15-20 minutes High-Density Cleaner: 3-4 stage cascade, inlet consistency 3-4%, reject rate below 8% Pressure Screen: 0.15-0.35mm slots, 2-stage screening, fiber recovery above 95% Double Disc Refiner: 660-910mm discs, 250-900 kW, freeness reduction 8-12 °SR per pass Paper Machine: 3200-4800mm wire width, 90-250 gsm, 350-500 m/min design speed Energy Performance Data Operating data from kraft liner mills shows the following energy benchmarks: Stock preparation power: 80-120 kWh per ton of pulp Paper machine drive power: 280-320 kWh per ton of paper Steam consumption: 1.6-1.8 tons per ton of paper (closed hood) Water usage: 8-12 m3 per ton (closed-loop recycling) These figures represent a 15-20% reduction compared to older configurations, achieved through optimized rotor designs, heat recovery, and VFD controls. Maintenance Guidelines Daily: Check lubrication levels, inspect doctor blade contact,...
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Multi-Layer Coating Board Production: Equipment for Premium ...
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 FoundationCoating 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% ISOUnder-top: Mixed bleached pulp (30-50 gsm)Middle/Filler: OCC or DIP (150-300 gsm), lowest cost layerBack layer: Unbleached kraft or OCC (50-80 gsm), for bending stiffnessKey Equipment for Each LayerTop Layer Preparation — Bleached Pulp RefiningThe 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 ProcessingThe 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 StockCoating board demands cleaner stock than liner or corrugating medium....
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Deinking Process Optimization: High Brightness Recycled Cult...
The Challenge of Recycled Cultural Paper ProductionProducing high-quality writing and printing paper from recycled fiber is one of the toughest challenges in our industry. Core Deinking Equipment ConfigurationA modern deinking line for 150-300 TPD cultural paper production needs a carefully sequenced equipment train. Here is the proven configuration Leizhan recommends:High-Consistency Hydrapulper with D-TopThe pulping stage sets the foundation. Leizhan high-consistency hydrapulpers operate at 13-18% consistency with a dedicated detrashing top (D-Top) that continuously removes lightweight contaminants. Key specs:Capacity: 150-300 TPDConsistency: 13-18%Motor power: 250-450 kWPulping time: 15-25 minutes per batchChemical addition: NaOH 0.8-1.5%, H2O2 0.5-1.0%, sodium silicate 1.0-2.0%Coarse and Fine Screening — Stickies RemovalStickies are the number one enemy of cultural paper quality. A two-stage screening system with 0.15-0.20 mm slots removes 85-92% of stickies particles before they reach the paper machine. Leizhan fine screens operate at 1.2-1.8% consistency with 75-110 kW motors.Flotation Deinking CellsThis is where brightness is won or lost. Multi-stage flotation cells (primary, secondary, tertiary) achieve 92-96% ink removal efficiency. Operating parameters: consistency 0.8-1.2%, air-to-stock ratio 0.3-0.5, residence time 8-12 minutes per stage. Target brightness gain: 12-18 points ISO.Washing and Thickening — Disc FilterAfter flotation, multi-disc filters remove residual ink particles and ash while thickening to 8-12% consistency....
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OCC Pulping System: Key Equipment for 400 TPD Kraft Liner Bo...
What Makes a High-Performance OCC Pulping Line? Core Equipment for 400 TPD Kraft Liner Production A complete OCC pulping system must handle high contamination loads while maintaining fiber strength. Here are the key components: Drum Pulper — The First Line of Defense The chain conveyor to drum pulper setup handles raw OCC bales with minimal fiber damage. Leizhan drum pulpers operate at 10-15% consistency with capacity of 400-600 TPD. The gentle tumbling preserves fiber length — critical for liner board strength. Capacity: 400-600 TPD Consistency: 12-15% Power: 15-18 kWh per ton Screen plate holes: 10-16 mm High-Density Cleaner After the drum pulper, an HD cleaner removes stones, metals, and glass before they damage downstream equipment. Leizhan HD cleaners achieve 98%+ removal efficiency at 3-4% consistency — saving mills $15,000-$25,000 annually in avoided screen basket replacement. Coarse Screening with Pressure Screens The pressure screen system is where many mills lose efficiency. For kraft liner board we recommend: primary screen 1.6-2.0 mm holes, secondary screen 1.4-1.6 mm holes. Motor power 55-90 kW primary, 37-55 kW secondary. Typical reject rate 12-18%. Fractionation Screening For multi-layer liner board, fractionation separates long fiber (surface layers) from short fiber (middle layer). Leizhan fractionation screens use 0.15-0.20...