Finish Appearance Challenges and Opportunities at · PDF fileand Opportunities at Boeing ... Boeing has addressed a range of 787 composite finishing challenges ... Landing gear doors

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Finish Appearance Challenges and Opportunities at Boeing Bruce Davis Boeing Research &Technology

April 12, 2011

COPYRIGHT © 2010 THE BOEING COMPANY

Earlier developments in aviation history have driven dramatic changes in finish requirements

Boeing Model C

1916

Boeing 247

1933

Boeing 707

1957 - 1978

Linen fabric, wood, and wire:

Nitrocellulose lacquer

Aluminum pigment

Aluminum Construction:

Epoxy and polyurethane enamels

Hexavalent chromium

Chemical and corrosion resistance


• Environmentally compliant coatings

• Extensive use of composite structure

• Globally distributed supplier base

The 787 Dreamliner has placed a new set of demands on aircraft finishes


Extensive use of composite structures delivers benefits and drives new challenges

• Lighter

• More durable

• Negligible corrosion

and fatigue

• Reduced scheduled

maintenance

• Opens new design

possibilities

• Presents new finishing

challenges

Carbon laminate

Carbon sandwich

Other composites

Aluminum

Titanium

Titanium/steel/aluminum

Aluminum

20%

Titanium

15%

Steel

10%

Other

5%

Composites

50%


Boeing has addressed a range of 787 composite finishing challenges

• Composite fuselage design

• Epoxy impregnated carbon fibers are

wrapped onto smooth tool surface which

after curing becomes interior of fuselage

• Caul sheets used to create smooth exterior

surface

• “Weave” texture can contribute to orange

peel-like appearance

• Challenge is to achieve acceptable finish

quality without resorting to fillers and

surfacers, which add weight and can lead to

cracking problems


Final exterior appearance development for composites requires consideration of many factors

Final Exterior

Appearance

Mold Release

Agents

Cleanliness

Detection

Surface

Preparation

Caul Sheet

Development

Part Design

Appearance

Inspection/

Expectation

Coating

Optimization

Surfacing Film

Development

Durability


Asia Fuji

Mitsubishi

Kawasaki

KAL-ASD

Canada Boeing

Messier-Dowty

Australia Boeing

U.S. Boeing

Spirit

GE

Goodrich

Europe Messier-Dowty

Rolls-Royce

Latécoère

Alenia

Saab

Wing tips Seoul, Korea

Moveable trailing edge Melbourne, Australia

Fixed trailing edge Nagoya, Japan

Wing Nagoya, Japan

Nacelles Chula Vista, CA

Tail fin Frederickson, WA

Horizontal stabilizer Foggia, Italy

Aft fuselage Charleston, SC

Passenger entry doors Toulouse, France

Center fuselage Grottaglie, Italy

Mid forward fuselage Nagoya, Japan Forward fuselage

Wichita, KS

Cargo access doors Linköping, Sweden

Wing/body fairing

Landing gear doors Winnipeg, Canada

Engines

GE – Evandale, Ohio

Rolls Royce – Derby, UK

Fixed and moveable

leading edge Tulsa, OK

Landing gear Gloucester, UK

Center wing box Nagoya, Japan

Main landing gear

wheel well Nagoya, Japan

48

47

46

44

43

41

11 45

Partners Across the Globe are Bringing the 787 Together


Distributed supplier base introduces additional challenges for exterior finishes

• Some sections come fully painted from supplier

• Wings, engine pylons, horizontal stabilizer

• Final assembly of these sections accomplished in Everett,

WA

• Requires approximately 25,000 pre-painted fasteners (heads

only) for assembly

• Over 20 different suppliers applying paint prior to assembly

• Color match issues led to establishment of requirement for

quantitative color match to standard Hide over representative substrates

0

0.5

1

1.5

2

2.5

3

3.5

0 1 2 3 4

Topcoat dry film thickness (mils)

delt

a E

SD Wing-Copper/BMS10-118

SD Wing-Blk/BMS10-118

SD Wing-Copper/BMS10-118

SD Wing-Blk/BMS10-118

SD Metlbond/BMS10-103A

SD Metlbond/BMS10-103A

SD Glass/BMS10-21/BMS103A

SD Glass/BMS10-21/BMS103A

Diel Top(BMS5-45)

Wing BMS8/276/BMS10-118


Large aircraft painting introduces more challenges

787 Dreamliner Premiere 07.08.07

• Surface preparation and paint application in same hangar

• Manual application of coatings


Numerous factors contribute to final paint appearance

• Substrate

• Layup, surfacer type, caul plate

type, etc.

• Surface prep method

• Any repairs

• Painter

• Experience

• Training

• Preferred technique (gun

triggering, gun distance to part,

cross coating, etc.)

• Equipment

• Type (AA, Electrostatic,

Conventional, HVLP, etc.)

• Settings (fluid flow rate, air

settings, etc.)

• Equipment maintenance

practices

• Environmental Conditions

• Temperature and humidity

• Process

• Paint thickness (target and

actual)

• Overcoat times

• Cure conditions

• Paint

• Rheology

• Cure profile

• Batch to batch color

consistency

• Hide

• Facility

• Air quality and flow patterns

• Booth contamination

• Painter access to part


Lab studies of application parameters may or may not correlate with production

• Charts showing orange peel at

different gun to part distance, spray

gun type and paint mix age

0

10

20

30

40

50

60

70

80

90

100

du dullness Wa 0,1-0,3mm Wb 0,3-1,0mm Wc 1-3mm Wd 3-10mm We 10-30mm

Wavescan Data as a Function of Paint Gun Type and Paint Mix Age

HVLP Gravity as Mix

HVLP Gravity Pot Life

HVLP Pressure as mix

HVLP Pressure Pot Life

Airspray Pressure as Mix

Airspray Pressure Pot Life

Airless, Air Assist as Mix

Airless, Air Assist Pot Life

Tension vs Spray Distance (36 in & 18 in.)

13.02

9.8810.09

8.39

7

8

9

10

11

12

13

14

18 inches 36 inches

Distance From Gun to Panel

Te

ns

ion Topcoat

Tension

PrimerTension


Customers and industry continue to demand more quantitative measurement of appearance quality

• Currently most requirements are qualitative:

• “The film shall be uniform in appearance…”

• “It is acceptable to have a slight color variation…”

• “Cosmetic defects and features shall not detract from the

overall appearance of the detail part or assembly…”

• Some quantitative appearance requirements exist:

• 60° Gloss

• Waviness

• Color match to standard (“non-decorative” areas)

• Currently studying additional quantitative measurements:

• Orange peel

• Color (decorative areas and special effects coatings)

• 20° gloss (more sensitive for high gloss coatings)


Each layer of exterior paint system requires unique appearance quality controls

• Need measurement and control at all levels of part

completion

• Substrate (metal or composite)

• Fillers and surfacers

• Primers and other undercoats

• Final topcoat (urethane monocoats, special effects coatings,

clear coats)

• Potential defects specific to layer

• Composite: pits, pinholes, roughness, waviness, resin

starvation…

• Primers and topcoats: blisters, contamination, cracking,

craters, crazing, drips, fish eyes, runs, sags, scratches,

seeding, solvent pop, wrinkles, overspray, dry spray, mottling,

orange peel…


Future challenges require on-going development commitment – Wish List

• Measurement of composite texture (“weave”)

prior to paint application

• Local shape measurement (depressions,

waviness)

• Quantitative measurement of pits and pinholes in

composites (unpainted, primed and enameled)

• Quantitative measurement of particle

contamination in enamels and primers


Wish List Continued • Wish List:

• Orange peel measurements on

very “peely” surfaces

• Mica and special effect coatings appearance characterization

• Strategy for establishing orange peel requirements for huge palette (hundreds) of customer colors

• What combination of Wavescan parameters best correlates with customer perception of quality finish?

• Paint thickness measurement on composites

• Stand off measurements of color and gloss


Questions Questions ?

Documents

Finish Appearance Challenges and Opportunities at · PDF fileand Opportunities at Boeing ... Boeing has addressed a range of 787 composite finishing challenges ... Landing gear doors