Curtain Coater as Air Knife Replacement - ppt.pdfCurtain Coater as Air Knife Replacement Martin...

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Transcript of Curtain Coater as Air Knife Replacement - ppt.pdfCurtain Coater as Air Knife Replacement Martin...

  • Curtain Coater as Air Knife Replacement

    Martin SchmidVoith Paper Inc.Appleton, WI

    PaperCon 2011 Page 2522

  • Content

    1. Introduction

    2. Curtain Coating

    3 Rebuild3. Rebuild

    4. Results

    5. Summary

    PaperCon 2011 Page 2523

  • Sustainability The Vision for the Future of Paper ProductionThe Vision for the Future of Paper Production

    Raw material Energy Water

    Maximizing the Reducing worldwide Lowering consumption Maximizing the recycling rate primary energy consumption by half

    of fresh water to less than 1 liter per kg

    PaperCon 2011 Page 2524

  • Long-term Demand Growth by Product Area through 2025by Product Area through 2025

    Tissue Containerboards3.0

    Average 1.9%/a Carton-boardsCoated woodfree2.0

    2.5

    owth

    [%

    /a]

    Coatedh i l

    Uncoated woodfree

    1.0

    1.5

    Dem

    and

    gro

    Source: Pyry

    Uncoatedmechanical

    Sackpaper

    Other grades

    mechanical

    News-print0.0

    0.5

    0 20 40 60 80 100Sh f ti i 2006 [%]

    90705030Share of consumption in 2006 [%]

    Above average growth rates for containerboards and cartonboards

    PaperCon 2011 Page 2525

  • Curtain CoatingSingle MultilayerSingle - Multilayer

    Single layer Double layer Multi layer

    Well proven slot die technology

    More than 30 references

    Based on the proven single layer concept

    Application of two different coating

    Slide die technology Multiple layers

    possible30 references

    For all paper and board grades

    different coating formulations

    No "teapot" effect

    PaperCon 2011 Page 2526

  • Curtain Coating

    Characteristics BenefitsCharacteristics Perfect coverage Excellent runnability High solids contents

    Benefits Improved printability Less break time Reduced drying energyg

    Ease of operation High efficiency No wear parts

    y g gy Wide coat weight range Higher content of recycled

    fibers Excellent handling Optimum CD and MD

    coat weight profiles

    PaperCon 2011 Page 2527

  • DeaerationTypical Air Content Blade Film and CurtainTypical Air Content Blade, Film and Curtain

    Air contentOffset 5-12

    Air contentOffset 5-12 before

    deaeration

    Acceptable

    BladeOffset

    Roto

    6-8

    5-1210-25

    beforedeaeration

    Acceptable

    BladeOffset

    Roto

    6 8

    5-1210-25

    -

    air contentafterdeaeration

    Film

    Curtain

    -

    8

    5-12

  • DeaerationVacuum deaerator for Curtain CoatersVacuum deaerator for Curtain Coaters

    Motor

    Color inlet Vacuum pump

    Cascade principle:

    3 X more surface at similar outer dimensions comparedouter dimensions compared to competition

    Color outletColor outlet

    PaperCon 2011 Page 2529

  • DeaerationVisualisation of Air Coating Color on a Glass PlateVisualisation of Air - Coating Color on a Glass Plate

    Before deaeration After deaeration

    PaperCon 2011 Page 2530

  • Curtain Coating Coverage effect with Curtain TechnologyCoverage effect with Curtain Technology

    Curtain Coater is capable to cover rawcapable to cover raw paper or board with low brightness!

    PaperCon 2011 Page 2531

  • Curtain Coating Brightness vs Coat WeightBrightness vs. Coat Weight

    PaperCon 2011 Page 2532

  • Pilot Trial Samples

    Air Knife(10 parts TiO2)12 / K 42%

    DF- Coater (10 parts TiO2)

    / %

    DF- Coater (no TiO2)

    12g/m K: 42% 12g/m K: 64,5% 12g/m K: 64,5%

    PaperCon 2011 Page 2533

  • Pilot Trial Samples

    Air Knife(10 parts TiO2)

    DF- Coater (10 parts TiO2)

    12g/m K: 42%

    200x

    12g/m K: 64,5%

    200x

    reduced cloudiness

    PaperCon 2011 Page 2534

  • Machine RebuildCurtain Coater for a Board MachineCurtain Coater for a Board Machine

    Substitution of an air knife by a curtain coater

    Products: several board gradesBasis weight: 230390 g/mMachine speed: 370550 m/minCoat application: 12 g/m pigment coat in the middle coatSolids content: 62 % (previously with air knife: 42 %)Width: 4850 mmStart up: May 2010

    Top coat: bladeMiddle coat: curtainPre coatBase boardBack side coat

    PaperCon 2011 Page 2535

  • Machine RebuildLayout with Air Knife Coater (Before Rebuild)Layout with Air Knife Coater (Before Rebuild)

    Backside Coater 5g/m / 45%g

    Pre-Coater5g/m / 50%

    Air Knife (middle)12g/m / 42%

    Blade Coater 11g/m / 68%

    PaperCon 2011 Page 2536

  • Machine Rebuild with Curtain CoaterMain Scope of SupplyMain Scope of Supply

    PaperCon 2011 Page 2537

  • Machine RebuildStart upStart-up

    First color on web on June 17, 2010

    Since June 18, 2010 in continuous operation

    June 19 and 20: 24hrs operation without a break

    Savings in drying energy immediately achieved(6 rows of IR instead of 14)

    Color curtain is very stable Color curtain is very stable

    Curtain formation after start is extremely fastextremely fast

    PaperCon 2011 Page 2538

  • Machine Rebuild QualityQuality

    Produced board was saleable from the 1st jumbo roll

    Coverage (opacity) and gloss are better than before

    Coat weight could be reduced

    Flatness was much better Sheeters could run faster

    Improved pick resistance Improved pick-resistance

    Better printability (no mottling)

    PaperCon 2011 Page 2539

  • ResultsCurtain Coater for a Board MachineCurtain Coater for a Board Machine

    Latest results: Superior coverage and reduced cloudinessR b ildReference:

    Air knife as middle coatRebuild: Curtain Coater as middle coat

    Precoat: 6 g/m rod coaterMiddle coat: 12 g/m air knife or curtain coater, resp.Top coat: 11 g/m bent blade

    contrast enhanced

    Top coat: 11 g/m bent blade

    PaperCon 2011 Page 2540

  • ResultsCoating LayerCoating Layer

    Air Knife

    Curtain Coater

    PaperCon 2011 Page 2541

  • ResultsCurtain Coater for a Board MachineCurtain Coater for a Board Machine

    PaperCon 2011 Page 2542

  • ResultsCurtain Coater for a Board MachineCurtain Coater for a Board Machine

    PaperCon 2011 Page 2543

  • ResultsCurtain Technology versus Air Knife CoaterCurtain Technology versus Air Knife Coater

    Superior coverage and clearly reduced cloudiness

    Best coating color distribution (CD + MD)

    Improved visual appearance by coating layer

    Si ifi t hi h lid t t (62 64 %) Significant higher solid content (62 64 %)

    No speed limit (v > 500 m/min)

    Wid t i ht (11 t 20 / ith t diffi lt ) Wide coat weight range (11 to 20 g/m without any difficulty)

    Very good runnability (no web break in the curtain coater since start up).p)

    PaperCon 2011 Page 2544

  • SummaryCurtain Coater for a Board MachineCurtain Coater for a Board Machine

    Furnish cost reductionFurnish cost reductionImproved coverage allows to replace DIP by mixed waste paper

    Production increase due to increased machine speedAir knife has been the bottleneck

    Energy savings Increase in solids content from 42% to 62% means 50% less water to be evaporatedp

    Coating cost reductionReduced pigment costs at maintained quality due to superior coverage of the coat (e.g. less TiO2 or lower coat weight, less binder)( g 2 g )

    PaperCon 2011 Page 2545

  • MM Frohnleiten KM3 - Pictures

    PaperCon 2011 Page 2546

  • Summary

    Curtain Coating is a Green Technologygy

    Energy savings due to: Higher machine efficiency Less drying requirements

    Increased use of recycled fibers Increased use of recycled fibers due to:

    Improved machine runnability Improved coating coverageImproved coating coverage

    PaperCon 2011 Page 2547

  • Thank You!

    PaperCon 2011 Page 2548