What_Are_Substrates used in car body in BIW

Define the type of metal substrates used in automotive OEM in manufacturing of a car body. The type of substrate in BIW ID IMPORTANT FOR COATING CRITERIA IN PAINT SHOP

1. What Are Substrates ?
A substrate is defined as a surface upon
which paint can be applied.
The correct preparation of any substrate
is a key factor to the adhesion, chip
resistance and long term durability of the
paint film.

2. Substrate Selection Factors
Corrosion Performance
Weight impact on Corporate Average Fuel
Economy (CAFE) standards
Design flexibility
Overall cost considerations

3. Different Substrates
Carbon Steels (Low Carbon, Medium Carbon &
High Carbon)
Stainless Steels
Coated Steels
Aluminium
Galvanised Steel
Cast Iron

4. Different Substrates
Plastics :- TPO (Bumper, Spoiler, instrument
Panel)
- ABS (Grills, mirror housing)
- PPO (Door handles / fuel lids)
- Nylon (Wheel caps)
- PC / PBT (Door handles)
- SMC
- Mineral filled polyanides
- FRP / MFN / GFN
- Low Density Structural Injection Molded
Polyurethane (LD-SRIM or RIM-Urethane)

5. Different Substrates
Polyether Sulphone (PES) (High Temp Electrical
Connection)
Polyphenylene Sulphide (PPS)
Polyethether Ketone (PEEK)
Polycarbonates (For headlamps lenses)
Polyester Polybutylene Terephthalate (PBT)
Polyethylene Terephthalate (PET)
PMMA for rear light lenses
Composite means plastic reinforced with fibres
usually glass

6. Different Substrates
Substrate made from recyclable Polypropylene and
Polyethylene Terephthalate provide a barrier to
absorb sound and reduce noice in the interior
compartment of a vehicle by 25 to 30 percent
(Improved acoustical performance)

7. Steel Sheets
Steel Class Hot Rolled Cold Rolled
Uncoated Uncoated EG HDGI HDGA
Mild Yes Yes Yes Yes Yes
Dent
Resistant
Non-Bake
Hardening
No Yes Yes Yes Yes
Bake
Hardening
No Yes Yes Yes Yes
High Strength Yes Yes Yes Yes Yes
Advanced
High
Strength
Dual PhaseDev Yes/
Dev
Yes/
Dev
Yes/
Dev
Yes/
Dev
Stretch
Flanging
Dev Dev No No No
TRIP No Dev No No Dev
MartensiteNo Yes Yes No No
EG : Electrogalvanized
HDGI : Hot-Dip-Galvanized
HDGA : Hot-Dip-Galvannealed
TRIP : Transformation Induced Plasticity
Yes : Products Commercially Available
No : No Products Commercially Available
Dev : Products are under development or in limited production

8. Potential for new materials for Automotive Engineering
Vehicle and component
performance & styling
Material &
Component Cost
Manufacturing
Cost & Constraints

9. Aluminium
Aluminium Alloy
Shot blasted aluminium
Sanded Aluminium
Oxidised Aluminium
Chromated Aluminium

10. Copper, Brass & Bronze
Cleaning
Sanding
Recleaning
Anticorrosion etch primer or an epoxy
primer

11. Methods of Surface Preparation
1.Cleaning : To remove surface contamination
- Solvent cleaning by hand
- Solvent cleaning by spray
- Solvent cleaning by dipping
2.Dry sanding : Various grades of sand paper
3.Blasting :
- Grit Blasting : Uses recyclable sand or grit
- Shot Blasting : Uses recyclable chilled iron shot
- Bead Blasting : Utilise plastic beads
For maximum durability
Average Amplitude x 3 = DFT of paint film required

12. Methods of Surface Preparation
Flash rusting of peaks
Low paint film thickness
If a coarse profile is obtained, sanding with 80 grit paper is recommended.
4. Chemical Cleaning / Pre Treatment
- Iron phosphating
- Zinc phosphating
- Manganesse phosphating
- 3 in 1 (Iron phosphating)
- Plastic pretreatment
5. For Plastics :- Solvent wiping (Deionised air spray required)
- Chemical Pre-treatment
- Corona Arc
- Flame burning

13. Construction Issues
Sharp edges should be rounded by sanding
End of cut sheet
Sharp edge
Extremely thin paint films on sharp edges are prone to corrosion

14. Construction Issues
Sealing of metal joints is extremely important
Panel
Rivet
PanelSealer needed here
Moister can penetrate the joint and then corrosion occurs

15. PRODUCT FOR TWO WHEELERS
PRIMER: - ALKYD + EPOXY – ESTER
- ISOLATING PRIMER
- ACRYLIC : (LATEST)
- 2K PU Primer
BASE : - TSA
- MODIFIED ALKYD
- POLYESTER (LATEST)
- 2K PU Base Coats
CLEAR COAT : - TSA
- MILKY CLEAR
- 2K PU Clear
ADHESION PROMOTING PRIMER FOR PP-EPDM.
CONDUCTIVE
PRIMER

16. ADVANTAGES OF W/W PRIMER
1)ROUGHNESS OF ED GETS FILLED
2)BETTER GLOSS AND DOI
3)UNIFORM UNDERCOAT FOR ALL SHADES
(OBLITERATE ED COLOUR)
4)COLOURED UNDERCOAT FOR DIFFICULT SHADES
LIKE RED, YELLOW. PEARL.
5)WITH PRIMER : LESS PROBLEMS IN PLASTIC –
PAINTING
6)YOU CAN BUILD IN FLEXIBILITY OF COMPOSITE
SYSTEM WHILE DESIGNING THE PRIMER.

17. ADVANTAGES OF MILKY CLEAR
BETTER ANTISAG
DFT INCREASE
BETTER FLOW AND LEVELLING
BETTER GLOSS AND DOI
REDUCED THICK-EDGE PROBLEM

18. 1.METALLIC SHADES AND PEARL-EFFECTS GETTING
MORE POPULAR
2.NON FADING CANDY REDS AND ITS VARIATIONS
3.WILL FOLLOW CAR INDUSTRY
4.THREE COAT FINISHES FOR BRIGHT EFFECT-
PIGMENT BASED SHADES.
5.AUTOMATIC APPLICATION FOR PLASTIC
COMPONENTS.
6.COMMON BASE COATS FOR METAL AND PLASTICS.
7.LOW BAKE PRODUCTS
8.COB
TWO WHEELERS
FUTURE TRENDS

19. PRODUCTS FOR TWO WHEELERS
PROCESS IN GENERAL
MS PLASTICS
PT
IPA WIPE / PT
CED
B/C-C/C SOLID T/C
W/W PRIMER
B/S-C/C OR SOLID
DECAL APPLN
LACQUER
B/C-C/CSOLID T/C
NEW TREND FOR
AUTOMATIC
APPLICATION
CONDUCTIVE PRIMER
BAKE OR W/W
B/C-C/C BY BELLS
(VORTEX BELLS)
DECAL
PU LACQUER

20. PRODUCTS FOR TWO WHEELERS
1.COMPLICATED DESIGNS OF COMPONENTS
2.HIGH LOADING ON JIG
3.SHADE MIS-MATCH BETWEEN TSA & PU
PRODUCTS.
4.QUALITY OF PLASTICS.
5.HIGH EXPECTATION OF FLEXIBILITY
6.COMPETITIVE PRICES
7.BELL Vs CONVENTIONAL
8.REQUIREMENT OF LOW BAKE
9.TWO COAT JOB
10.HIGHER EXPECTATIONS OF GLOSS AT LOWER DFT
CRITICAL FACTOR

21. PRODUCTS FOR TWO WHEELERS
11.BLISTERING AT EDGES
12.POOR DRY-OFF FOR PLASTICS
13.POOR CONTROL IN SPRAY BOOTH
14.HIGH FREQUENCY FOR SHADE – INTRODUCTION
15.FADING IN CANDY
16.STICKER QUALITY VARIATION
CRITICAL FACTOR

22. DO AND DON’TS
ENSURE
i ) QUALITY OF SHEET METAL
ii ) QUALITY OF PRE-TREATMENT
iii) WHETHER ALL EQUIPMENTS ARE WORKING PROPERLY.
[APPLICATION EQUIPMENT, PRESSURE FEED VESSELS, ON LINE
FILTERS, AIR-COMPRESSOR, PUMPS, CONVEYER, OVENS,
BURNERS, BLOWERS ETC.]
iv ) USE OF APPROPRIATE THINNER / SOLVENT.
v ) CONVEYER – SPEED
vi ) JIG – CLEANING
vii) OVEN – TEMPERATURE.
A] PRIOR TO PAINTING

23. DOs AND DON’TS
CONFIRM
i ) PAINT POT AGITATION / CIRCULATION
ii ) APPLICATION VISCOSITY AT SPECIFIED TEMPERATURE
iii ) APPLICATION PRESSURES
iv ) PAINT – FLOW RATE
v ) APPLICATION RESISTIVITY
vi ) APPLICATION VOLTAGE
vii) QUALITY OF COMPRESSED AIR
viii) DUST-FREE ENVIRONMENT
ix ) TEMPERATURE AND HUMIDITY IN SPRAY – BOOTH
x ) ROTATIONS PER MINUTE, OF BELL / DISC
xi ) DISTANCE BETWEEN SPRAY-EQUIPMENT AND ARTICLE TO BE
PAINTED
B] DURING PAINT APPLICATION

24. DO AND DON’TS
CHECK
i ) FLASH – OFF PERIOD
ii ) DUST – FREE ENVIRONMENT IN FLASH – OFF ZONE
iii ) PROPER AIR – CIRCULATION IN OVEN
iv ) CAREFUL UNLOADING
C] AFTER PAINT - APPLICATION

25. PRE APPLICATION FACTORS
STORAGE OF PAINT :
• AT MODERATE TEMPERATURE
• STOCK ROTATION : OLDER MATERIAL IS USED FIRST
• INVERT CONTAINERS AT REGULAR INTERVALS
MIXING :
• PAINT SHOULD BE THOROUGHLY MIXED
• MECHANICAL (MOTORISED PROPELLER)
AGITATION RECOMMENDED
• MIX SHOULD LOOK UNIFORM
THINNING :
• THINNER SHOULD BE MIXED SLOWLY
• CONTINUOUS CIRCULATION SYSTEM RECOMMENDED
• ON LINE STRAINERS

26. APPLICATION PARAMETER
PAINT CIRCULATION SYSTEM
STRAINING OF THINNED PAINT
SPRAY BOOTH
- WATER CURTAINS
- DUST FREE ATMOSPHERE
- HUMIDITY/TEMPERATURE CONTROL
- EXHAUST FACILITIES
- PRESSURE
PAINTING SEQUENCE
FLASH OFF ZONE
- TIME FACTOR
- DUST FREE ATMOSPHERE
- HUMIDITY / TEMPERATURE CONTROL
- EXHAUST FACILITIES
SANDING PRACTICES
TACK-RAG
PRE-TREATMENT QUALITY
SHEET METAL QUALITY

27. CHOICE OF APPLICATION
STATE OF COATING MATERIAL
: SOLID, LIQUID OR POWDER
TYPE OF COATING MATERIAL
: WATER BORNE OR SOLVENT BASED
SHAPE OF SURFACE
: FLAT OR CONTOURED
NATURE OF SUBSTRATES
: WOOD, ALUMINIUM, STEEL
MODE OF CURING
: SINGLE PACK / TWOPACK / AIR DRYING / STOVING
ECONOMY OF APPLICATION DEMANDED
SAFETY OF APPLICATION
DEPENDS ON :

28. METHOD OF APPLICATION
BRUSHING
DIP APPLICATION
FLOW COATING
SPRAY APPLICATION
- COMPRESSED AIR
- ELECTROSTATIC
- HOT SPRAYING
- AEROSOL
- TWO COMPONENT SPRAYING
CURTAIN COATING
ROLLER COATING
BARELLING
ELECTRODEPOSITION
POWDER COATING :
- FLUIDISED BED
- ELECTROSTATIC
- ELECTRO FLUIDISED BED
AIR ASSISTED
AIRLESS
AED
CED

29. PAINT APPLICATION METHODS
DIP
SPRAY
CONVENTIONAL
CONVENTIONAL
ELECTROPHORETIC
(WATER-BORNE)
ELECTROSTATIC
WATER BORNE
SOLVENT BORNE
ANODIC
CATHODIC
AIR - ASSISTED
AIR - LESS
AIR - LESS
AIR - ASSISTED
CENTRIFUGAL
DISC
BELL

30. FACTORS GOVERNING SELECTION OF
APPLICATION EQUIPMENT
1.TYPE OF PAINT USED
2.METHOD OF APPLICATION
3.STANDARD OF FINISH DESIRED / ACCEPTABLE
4.ECONOMY IN PAINT UTILISATION
5.VOLUME AND RATE OF PRODUCTION
6.SHAPE AND COMPLEXITY OF THE COMPONENT TO
BE PAINTED
7.CAPITAL INVESTMENT FOR EQUIPMENTS
8.ENERGY : AVAILABLE AND COST
9.SAFETY AND ENVIRONMENTAL STANDARDS
ENFORCED

31. FACTORS DECIDING SELECTION OF APPLICATION
EQUIPMENT
STANDARD OF FINISH DESIRED / ACCEPTABLE
VOLUME / RATE OF PRODUCTION
SHAPE / COMPLEXITY OF COMPONENTS
CAPITAL INVESTMENT
ENERGY : AVAILABILITY / COST
ECONOMY IN PAINT UTILISATION
SAFETY / ENVIRONMENTAL ASPECTS
TYPE OF PAINT METHOD OF APPLICATION
SYSTEM TO BE USED BOOTH & OVEN TYPE

32. DO’S & DON’TS FOR BETTER PAINT APPLICATION
1.ENSURE THROUGH CLEANING OF SURFACES
2.USE RECOMMENDED PRETREATMENT
3.USE ONLY RECOMMENDED THINNER
4.ENSURE PROPER MIXING OF PAINT
5.ENSURE PROPER QUALITY AND CLEANING OF
SPRAY GUN, DISCS, ETC
6.PAINTS IN CLEAN, DUSTFREE BOOTH
DO’S
N.B.: TO GET BEST PAINT PREFORMANCE, MANUFACTURER’S
RECOMMENDATIONS AND INSTRUCTIONS SHOULD BE
STRICTLY ADHERED TO.

33. DO’S & DON’TS FOR BETTER PAINT APPLICATION
1.DO NOT THIN PAINT EXCESSIVELY
2.DO NOT APPLY VERY THICK COATS
3.DO NOT APPLY ANY COAT WITHOUT CURING OF VIOUS
COAT
4.DO NOT ADD ANY MATERIAL OTHER THAN
RECOMMENDED
5.DO NOT WORK WITH FAULTY EQUIPMENTS
6.DO NOT PAINT IN DUSTY ENVIRONMENT
DON’TS
N.B.: TO GET BEST PAINT PREFORMANCE, MANUFACTURER’S
RECOMMENDATIONS AND INSTRUCTIONS SHOULD BE
STRICTLY ADHERED TO.

34. APPLICATION METHOD YIELD
AIR SPRAY : 30 – 60 %
AIR LESS : 50 – 80 %
ELECTROSTATIC : 80 – 95 %
CONVENTIONAL DIP : 85 – 90 %
ELECTRODEPOSITION : 90 – 97 %