Coating Blankets

8/3/2019 Coating Blankets

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Coating Blankets


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What is a coating?

A coating is a clear layer applied to all, or part of asheet after printing - achieving a variety of finishes.

Before drying, most coatings are opaque liquids,quite unlike a sheetfed ink.

Coating is commonest in carton printing, but alsowidespread in commercial printing.


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In-line and off-line coating

In-line coating - Printed then coated on the same press in one pass.

Off-line coating - Printed then coated as a separate process on another machine.

PRINTING COATINGDEDICATEDCOATING UNITS

PRINTINGCOATING


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Why are sheets coated?

Improved appearance - higher gloss, brighter look,special finishes etc.

Protection - stops the image rubbing, scuffing etc.(also known as a sealer).

Faster processing - cutting and creasing etc.

Sometimes two coatings are applied to a sheet (double

coating).


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Coating types

Chemistry/drying process:

Aqueous (or water based/dispersion) - dried with hotair or infra red radiation (80% of the market).

UV - dried with UV radiation (20% of the market).

Finish:

Gloss

Satin

Matte


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Terminology

Gloss:

The ability of a surface to reflect directed light.

Has an effect on colour and brightness.

Slip:

The slip value of a coating is chosen to suit processing(folding/gluing) and/or the final application.

Laydown:

How smooth and even the coating appears.

Bad laydown means mottle or orange peel effect. More critical on matte than gloss coatings.


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Coating terms and types

Knock outs or glue flaps (75% of cartonmarket)

Selected areas only, e.g. carton work.

No fine details.

Use a Coating Blanket.

Flood coating (15%)

Whole sheet coated, no detail. Use any Printing Blanket.

Spot coating (10%)

Detailed text or halftones.

Use photopolymer plate (Cyrel, Nyloprint etc).

Alternatively use a litho varnish (clear ink).

Spot coatingfor detailed

work


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Why bother with knock-outs?

Coatings can cause problems in carton printing.

Glues wont stick to most coatings.

Nor will inks used to print sell by dates etc.

Areas of the blanket must be cut and stripped away tomake a STENCIL so they will not transfer coating.


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Knock outs and glue flaps

Coated areas

Non coated areas

Carton coating design

Glueflaps

Date box

Coating blanket

stripping patternNon stripped areas

Stripped areas

Glue flap outline


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How is the stencil prepared?

Cut by hand - on or off press

Cheap but inconsistent, lessaccurate.

Cut by CAD/Plotter

Fast and accurate.

The blanket is always stripped by hand!


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Roller versus Anilox coater

Impression cylinder

Plate/blanketcylinder Fountain

roller

Paper/board

Coating

Coatingroller

Impression cylinder

Plate/blanketcylinder

Doctorblade

Paper/board

Coating

Anilox

roller

Anilox coater unit

The anilox roller is solidmetal or ceramic, with tinycells in its surface.

The coating film weight iscontrolled by the cell size.

Roller coater unit

The coating roller is coveredwith solid rubber.

The coating film weight iscontrolled by pressurebetween the rollers.


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Why use a Duco stripping blanket?

Dedicated coating blanket design.

Consistent stripping properties.

Optimum coating properties.

High smash resistance/durability.

Widest range available.

3 different backing options.


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Whats wrong with the alternatives?

Old printing blankets

Poor and inconsistent stripping properties.

Poor and inconsistent coating performance.

Often damaged by smashes etc.

Photopolymer plates

High costs - can be up to 4 x coating blanket cost. Easily damaged - printer may have to buy spare.

Availability - off site processing.

Limited gauge range. Processing waste.

Environmental impact - chemical usage.


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Duco coating blanket range

Worlds largest range of coating blankets.

Available in gauges from 0.90mm to 1.95mm.

Fabric backed Polyester backed Sticky backed


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BaseCastAdhesive0.95, 1.05,

1.68 & 1.95

Superstrip SB

SpongeCastPolyester1.95Superstrip PB &

UVPB

SpongeCastPolyester1.95Superstrip PB

Ultra

BaseMicro ground

(*also cast)Polyester

1.15, 1.30*,

1.35 & 1.40Superstrip PB

SpongeCastFabric1.68 & 1.95Superstrip FB &

FBLR

Strip toSurfaceBackingGaugesProduct


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1.68Mitsubishi

1.95Ryobi

1.95Komori

1.30 1.40KBA

1.95Manroland

1.95Heidelberg

Compatible blanket gaugePress type

Please considerthat thinnercoating blanketsor plates may beused with the

appropriateadjustment inunderpacking.


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Documents

Coating Blankets