Underbody Coating

UNDER BODY COATING :-

Automobile made up of diff steel material contain 95-98% of iron 2-5% of alloys by combinig diff materials,So the iron easily undergoes oxidation(FE2+O3-->FE2O3 IN PRESENCE OF H2O) process hence to reduce the effect of corrosion under body coating is introduced ,before automotive painting.

Automotive Underbody coating is a protactive coating applied under side of vehicles against the damage according by several factors like chemical,water moisture and impatc damage from small stones.it helps prolong the life of vehicles.it also protects parts like internal body panels,frame rails and other inner cavities that are not physically accessible but are prone to corosion.

Now 3M has this underbody coating that is pretty thick and comes with a five year warranty.

BEFORE UNDERBODY COATING

AFTER COATING WITH 3M

The global automotive underbody coatings market can be segmented as:

On basis of end use:

1)OEM 2) AFTER SALES MARKET

On basis of coating type:

1)SOLVENT BASED(oil) 2) WATER BASED(Latex)

In solvent based paaint -mineral spirit is the diluent,water based-water is diluent.

Basis of coaating method:

1)SPRAY APPLIED 2) BRUSH APPLIED

Some of the market participants operating in the global automative underbody coating market:

1)3M

2)Sika AG

3)Henry Compony

4)Henkel Corporation

5)PPG

6)The Sherwin-Williams Company

7)CONVESTRO AG

BENEFITS:

MINIMIZES SOUND

HEAT INSULATION

ANTI CHIPPING PROPERTY

MODERN AUTOMOTIVE COATING PROCESS:

Automotive coating process comprises minimum 5 layers of paint, underbody coating process comprises the first two layers in the overall coating process.

Pre Treatment:When the automobile body sheet metal components are welded together, the resulting structure is referd ta as BIW.Pre-treatment consists of cleaning the body surface to remove remaining oils from the stamping process and welding residues through three primary liquid dip.process of degreasing,cleaning.pre treatments helps the primary to bond on to the metal.

Phosphate treatment applies metal phosphate layer providing resistance to corosion spread.

E-coating involves dipping automobile bodies intothe coating solution & passing an electric current through thebody & the liquid ED paint solution. Because of the charged nature of this coating process, the ED paint penetrates intoplaces a spray would not reach.During operation, a mixture of resin, binder, & a paste containing the pigments is fed into the ED tank. The automobile body is lowered into the tank, & an electric current applied; the solution in the tank consists of 80-90% deionised water & 10-20% paint solids.The resin is the backbone of the final paint film & provides corrosion protection, durability, & toughness. Pigments are used to provide color & gloss. After E-coat, the automobile body enters a bake oven, in which heating & keeping at a temperature of 160_C for 10 min causes film curing to promote maximum performance properties. The oven temperature & heating time primarily enchance chip resistance & film adhesion to the body; corrosion protected is affected less by these conditions. Because surface roughness influences the smoothness & brilliance of the topcoat, some sanding of the surface is usually performed to remove or eliminate defects before the body enters the next application step. A common challenge in the cureent E-coating process is that of water spots that contaminate coated surfaces. If water spots are present, they have removed ny sanding. Hence, it is necessary to use well-deionoised water & routinely monitor its conductivity. Alternstely, operators also add surfactants or ultrafiltrates to the water rinse zone to eliminate or manage water spots.