7 Finishing - EWFD 2012.ppt - Stiles Machinery · UV sealer coats UV sealer coats MUSTMUST be sanded well to obtain intercoat adhesion Possible to semiPossible to semi--cure between

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Engineered Wood Flooring DaysBuilding Profits through Technology

Finishing Technologies

A PROCESS GUIDE TO PRE‐FINISHED

ENGINEERED WOOD FLOORING

bob kostelnik may 2012

Engineered Wood Flooring Days

bob kostelnik – may 2012

Finishing TechnologiesFinishing Technologies

EWFD FINISHING SEMINAR

Typical Finish Process GUEST INDUSTRY EXPERTS

Edge Coating Bevels

Digital Printing

GUEST INDUSTRY EXPERTS

Brent Warren – Burkle Roll CoatersStefan Schiele – Schiele TransferDiscDigital Printing

Kaindle Flooring VideoSteve Williams – CCI CoatingsFrank Schneider – Klumpp CoatingsRoy Pagan – Durst Digital Printers

Note: Seminar will be followed immediatelywith finishing process demonstration in Lab


with finishing process demonstration in Lab


PRE‐FINISHING IS A 5 STEP PROCESS

White Wood Sanding

Staining

S liSealing

Sealer Sanding

Topcoat



WHITE WOOD SANDING (step1)


WHITE WOOD SANDING (step1)NOTE: pictures shown for example onlyand are not intended as a recommendation

details of sanding in another seminar



STAINING (step 2)


Use 100% solids UV stains

Apply by Roll Coater with 25 30 shore EPDM rubber flat surfaceApply by Roll Coater with 25 – 30 shore EPDM rubber flat surfaceusually 1 roll is sufficient quantity

Apply approx 20 – 25 grams per square meterApply approx 20 25 grams per square meter

Brush wipe with nylon bristle brushes (2 brushes in opposing directions)

UV Cure (about 5 seconds) 2 UV Gallium lamps



RCL Single Head Differential Roll Coater

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• Used for application of:

• Clear Sealers

• Clear Finish Coats

• Pigmented Base Coats

• Stains

• By far, the most common type of roll coater in use

• On a typical production line, if there are 9 roll coaters, 8 would be RCL type

• The term “differential” refers to the ability of the Doctor Roller to roll in clockwise OR counter-clockwise direction

• clockwise = direct mode = more film applied (stains)• counter-clockwise = indirect mode = less film applied but much smoother (clear or pigmented finish coats)







Rubber Applicator Roll Chrome Doctor Roll



ROLLER RUBBER AND HARDNESS


-In most applications, rubber is EPDM

Typical recommended hardness of rubber-Typical recommended hardness of rubber rolls used on a roll coat line:

- Stains – 18 Shore Sponge (water)- Stains – 30 Shore (100% solids)- Sealers – 35 Shore- Topcoats – 45 Shore

- Hand scraped flooring requires much softer- Hand scraped flooring requires much softerrubber to cover the depressions in the surface. Usually in the 15 – 20 shore range



ROLLER RUBBER AND HARDNESS


Shore Durometer:

“Durometer” is one of several measures of the hardness of a material. hardness may be defined as a material’sresistance to indentation. The durometer scale was defined byyAlbert F. Shore, who developed the Durometer in the 1920s.

The terms Durometer and Shore are used interchangeably and refer to the measurement as well as the deviceto the measurement as well as the device.



COATINGS USED WITH ROLL COATERS


• The most common chemistry type, by far, is 100% solids UV

• clear coats

i t d b t• pigmented basecoats

• fillers

• stains (new)

• Other chemistries

• water based basecoats

• water based stains

• water based fillerswater based fillers

• solvent based stains

Note: other than solvent stains, solvent coatings are very rare with roll coat systems


rare with roll coat systems.


COMPOSITION COMPOSITION –– typical coatingtypical coating


Petroleum-based or water

SOLVENT(VOLATILES)

“normal” solidsContent 30-40 %

Solids:SO S Solids:Resins, pigments, additives and fillers

SOLIDS



COMPOSITION COMPOSITION –– 100% solids UV100% solids UV


UV lidUV solidsContent 100%

100 % Solids

Solids: MonomerSolids: Monomer,Resins, Pigments, Additives and Fillers



BENEFITS OF UV COATINGS ( when applied by roll coating)


• Green chemistry – No formaldehyde and zero to very low VOC

• Instant cure with no flash zone (when 100% solids)

• Totally cures (cross links) in seconds with no apparent “post cure” waiting

• Not thermoplastic – will not “block” at end of line

• Highest performance – chemical and scratch resistance

• Recycled – not Reclaimed

• Easy to maintain equipment

• Near 100% transfer efficiency



BENEFITS OF UV COATINGS (roll coating)


• Lowest possible cost per square foot.

• $.04 - $.07 per square foot.

• Best cost of any spray coating is $.20 - $.25 (UV by spray is about $.35 per square foot)

• Why so inexpensive?

• no solvent or water evaporated (yes even water is expensive when part of a coating)

• 100% transfer efficiency (all gallons purchased are utilized on a part)

• very small amount applied



Roll Coating Film Thickness:


The largest application “problem” with roll coating is that of “roping”. “Roping” describes an appearance imagining stringsor ropes laid out touching each other in parallel lines. In most cases this appearance is unacceptable.

When roll coating this appearance starts to occur when more than .7 mils (.0007 “) is applied with 1 roller. Typically, a qualityAppearance requires no more than .5 mils per head. Therefore if 3 heads are used for sealer there is only about 1.5 mils (.0015”)to sand with a wide belt sander.

Topcoats are typically applied with two rollers (wet on wet) at only .3 mils wet each for a total of .5 mils ( one half of 1/thousand in.)p yp y pp ( ) y ( )

In order to measure films that small, we use gram weight:

If a UV coating weight 9 lbs per gallon, we calculate that to be 25 grams per square meter per 1 mil. If we want .5 mil that equals12.5 grams per square meter or 12.5/10.76 = 1.16 grams per square foot.

- - - - - - A very small amount



BURKLE TRUV & TRUVTC UV OVENS


Machine in lab



Elliptical ReflectorElliptical Reflector


Elliptical ReflectorElliptical ReflectorFocal point on coated partFocal point on coated part




UV C Li k CUV C Li k C


UV Cross Link CureUV Cross Link Cure

UV cured coatings are UV cured coatings are NOTNOT thermoplasticthermoplastic

UV sealer coats UV sealer coats MUSTMUST be sanded well to obtain intercoat adhesionbe sanded well to obtain intercoat adhesion

Possible to semiPossible to semi--cure between coats cure between coats

“B” stage“B” stage

G lliG lliGellingGelling

Applied coat is dry but not curedApplied coat is dry but not cured

Sanding is not requiredSanding is not required



HOW MANY LAMPS?


In general 1 lamp per 30 fpmline speed.

If the line is small and runs At 25 fpm, it is best to haveTwo lamps and run both atHalf or reduced power.p

Typical Lamp Life:2,000 hours mercury

700 hours Gallium

Lamps should have ability ofVariable power adjustment



SEALER APPLICATION (step 3)

Use 100% solids clear UV Sanding Sealer

Apply with Roll Coater 35 shore EPDM rubber 3‐4 heads normally required

A l 12 15 t h dApply 12 ‐15 grams square meter per head

UV “gel” (semi‐cure) with 1 mercury vapor lamp between coats

UV Cure total film with 2 or more mercury vapor UV lamps


.


SEALER SANDING (step 4)NOTE i t h f l l dNOTE: pictures shown for example only and are not intended as a recommendation

details of sanding in another seminar



Aluminum Oxide (Alox)

One on the hardest known materials (just less than Diamond)

When powder is suspended in UV resins, the coating is extremely hard and abrasion resistant

Primarily used when finishing commercial flooring when high wear resistance is required

Commercial flooring usually requires very high Taber abrasion cycles

Since it is an opaque white powder, it detracts from finish clarity

Commonly used is first one or two sealers with one or two more subsequent coats normal sealersince Alox bearing sealer is VERY difficult to sand.



Accelerated Wear TestAccelerated Wear Test

Taber Abraser

Coated samples are subjected to the action of twoabrasive wheels at a known load and rotated in opposite directions.

Typical abrasion test for flooring500 – 1000 grams500 – 1000 cyclesS42 wheels (sandpaper stripsS42 wheels (sandpaper strips



TOPCOAT APPLICATION (step 5)

Use 100% solids clear UV Topcoat


Use 100% solids clear UV Topcoat

Apply with Roll Coater 45 shore EPDM rubber 2 -3 heads normally requiredq

Apply 12 -15 grams square meter per head

UV “gel” (semi-cure) with 1 mercury vapor lamp between coats

UV Cure total film with 2 mercury vapor UV lamps



Single Pass Finishing Line for FlooringSingle Pass Finishing Line for Flooring





Schiele TransferDisc

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Designed for precision coating of beveled edges of laminate or parquet flooring




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Preferred installation is on the same transport as the cutting tool for the bevel

Speed is synchronized with speed of the production lineSpeed is synchronized with speed of the production line




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Disc rotates into a chilled coating reservoir

Coating is transferred to angled metal disc then to bevelg g


Fi i hi T h l i



Coating thickness is adjusted by the pressure of a brass wiper blade that is adjustable in 1/100 mm increments

Brass blade

Transfer disc



Thickness adjustmentSchiele TransferDisc

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brass scraper blade

Transfer disc

Disc in/outand angleadjustment





Coatings may be:

Water Basedor100% Solids UV100% Solids UV

Hot air dryer for water base



DIGITAL IMAGING



LARGE FORMAT INK JET DIGITAL PRINTING


Wood and other rigid substrates

OCE” commercial printer 100 to 450 sq ft/hr

DURST industrial printer 800 - 3000 sq ft/hr

DURST continuous pass printer to 150 fpm


DURST continuous pass printer to 150 fpm


THE PROCESS ‐‐‐‐‐‐‐‐Digital Printing


High speed ink jet printing of wood grains or other decorative patterns on rigid substrates up to 5ft x 10ft part size.

Replaces traditional off set printing by engraved rollers.

Primers, stains, topcoats applied with traditional roll coating equipment

May be installed “stand alone” or “in‐line”



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Utilize off spec or off color veneer

Applications - - from “mass production” to “mass customization”

Use low cost plywood to produce the look of very high cost or rare decorative species

In paper laminating production methods, ink print small batches or custom work

Print exotic wood grains over low cost hardwood flooring

Use low cost white HPL and decorate with any imaginableUse low cost white HPL and decorate with any imaginable natural or created pattern

Print any pattern or art work rather than silk screening directly on to rigid substrate



ADVANTAGES

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Create high value with low cost “sustainable” materials

ADVANTAGES- - - -

Create high value with low cost sustainable materials

Total design flexibility

Low volume custom order capability

All liquid coatings and inks totally “green” and LEED compliant

No physical set or clean up time required

No downtime between jobs

Fast turn around time

Full relief decorating on uneven surfaces


Full relief decorating on uneven surfaces


DIGITAL IMAGING SYSTEM FOR FLOORING




Stiles new “state of the art” printer in our High Point lab (June 1, 2012)

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Durst Rho P10

-1000 DPI

- 2 mt wide print capability

6 color printing- 6 color printing

- UV inks

- up to 1800 sq. ft. per hour

Durst R & D Center Lienz Austria


Durst R & D Center. Lienz, Austria

Finishing Technologiesg g

Single Pass Digital Imaging Flooring Line Video

Finishing Demonstration in Lab


Documents

7 Finishing - EWFD 2012.ppt - Stiles Machinery · UV sealer coats UV sealer coats MUSTMUST be sanded well to obtain intercoat adhesion Possible to semiPossible to semi--cure between