Lesson 1Brownstock washing principles: dilution, displacement, and counter-current washingDis cover dilution and displacement mechanisms, shower and drum operation, and counter-current layouts. E emphasize washing efficiency, soda loss, filtrate reuse, and impacts on evaporators, recovery boiler, and downstream fiber quality, so you fit understand how to do am proper.
Dilution and displacement washing mechanismsWashing factor, dilution factor, and soda lossWasher types: drum, DD, pressure, and beltFiltrate segregation and counter-current circuitsEffects on evaporators and recovery boiler loadImpacts on bleaching chemistry and fiber qualityLesson 2Drying section basics: dryer cylinder operation, temperature profiles, runnability factors, and reel windingE explain dryer cylinder operation, steam and condensate systems, and hood ventilation. Cover temperature profiles, pocket ventilation, sheet draws, and runnability, ending with reel winding principles, tension control, and roll structure, to help you manage di drying well.
Steam groups, condensate removal, and siphonsCylinder surface temperature and heat transferPocket ventilation and humidity managementSheet draws, threading, and runnability limitsDryness profiles and curl or cockle controlReel winding tension, nip, and hardnessLesson 3Bleaching sequences for wood-free papers: typical chemical stages and objectivesE detail common bleaching sequences for wood-free grades, including oxygen, peroxide, and chlorine-free stages. Explain stage objectives, selectivity, brightness targets, chemical interactions, and impacts on strength, dirt, and environmental load, so you sabi how to bleach proper.
Typical ECF and TCF sequences for wood-free pulpStage objectives: O, D, E, P, and peroxide stagesBrightness development and reversion controlChemical selectivity and fiber strength retentionCarryover limits from washing to bleachingEnvironmental and effluent considerationsLesson 4Overview of kraft pulping and brownstock composition and contaminantsE explain kraft brownstock composition, residual lignin, extractives, and entrained black liquor. Cover contaminants, shives, metals, and carryover wey influence washing efficiency, bleaching cost, sheet defects, and recovery load, helping you know di full picture.
Kraft cooking reactions and delignification profileTypical brownstock kappa, viscosity, and brightnessOrganic and inorganic contaminants in brownstockImpact of shives and knots on downstream operationsCarryover to washing, bleaching, and recoveryLesson 5Stock preparation: screening, cleaning, blend control (hardwood/softwood) and consistency managementE describe screening, cleaning, refining interface, and hardwood–softwood blending. Focus on consistency control, contaminant removal, fiber fractionation, and how stock prep settings influence formation, strength, and runnability on di machine, for better preparation.
Coarse and fine screening efficiency targetsCentricleaners and removal of heavy contaminantsHardwood and softwood blend strategiesConsistency control loops and instrumentationRefining location relative to screening stagesEffects on formation, strength, and defectsLesson 6Mass and energy balances across the fiber line: yield, solids flow, steam and condensate flowsE develop mass and energy balances across di fiber line, from brownstock to reel. Include yield, solids and liquor flows, steam and condensate circuits, and how balances support troubleshooting, optimization, and cost tracking, to make operations efficient.
Defining system boundaries and process mappingFiber yield, rejects, and loss accountingSolids, liquor, and filtrate flow balancesSteam, condensate, and heat recovery loopsUsing balances for troubleshooting and auditsLinking balances to cost and KPI trackingLesson 7Approach flow systems: save-alls, blending chest, screens, and chemical additionsE explore approach flow layout from machine chest to headbox. Cover mixing and blending chests, screens, cleaners, save-alls, and chemical addition points, emphasizing stability, basis weight control, and short-circulation cleanliness, for smooth flow.
Machine chest, mixing chest, and level controlFan pump function and pressure stabilityApproach flow screening and cleaning stagesSave-all systems and white water recoveryChemical addition strategy and timingBasis weight and dilution control systemsLesson 8Interdependencies: how changes in washing, bleaching, refining, or forming affect downstream moisture, strength and steam demandE show how washing, bleaching, refining, forming, pressing, and drying interact. Emphasize how upstream changes shift moisture, strength, porosity, and steam demand, and how to diagnose root causes using cross-section data, to fix problems quick.
Washing carryover effects on bleaching and dryingRefining impacts on drainage, strength, and energyForming quality versus pressing and drying limitsPress dryness and downstream steam consumptionBleaching and strength tradeoffs in final sheetSystematic root cause analysis across the lineLesson 9Forming section fundamentals: headbox hydraulics, slice setting, jet-to-wire ratio, and forming fabricsE introduce headbox hydraulics, slice opening, and jet-to-wire ratio. Explain turbulence generation, fiber orientation, forming fabric design, and drainage elements, linking settings to formation, CD profiles, and two-sidedness, for good sheet formation.
Headbox types: open, hydraulic, and dilutionHeadbox consistency and turbulence intensitySlice opening, lip profile, and CD controlJet-to-wire ratio and fiber orientation effectsForming fabric design and conditioningDrainage elements and vacuum box settingsLesson 10Pressing and consolidation: nip types, press loading, press felts and water removal mechanismsE cover press nip types, loading strategies, and press felt design. Explain water removal mechanisms, nip dwell time, void volume, and rewet, and how pressing influences dryness, bulk, strength, and steam demand in di dryer section, to improve pressing.
Single, double, and shoe press configurationsPress loading, line pressure, and nip dwell timePress felts, void volume, and conditioningMechanisms of water removal and rewetPress dryness versus bulk and strength tradeoffsImpacts on dryer steam demand and runnability
