Underbody Coating

UNDERBODY COATIND

Underbody coading in automobiles is a method of applying chemicalcomponent mixures to a BIW's underbody,internal and external panels.This processes are performed by depending upon OEM's facilities like manual,semi-automated rails or automated robots.Underbody coating provides longterm protection from corrosion of cars underbody.It also protects parts like internal body panels,frame rails and other inner cavities that are not physically accessible but are prone to corrosion.Ingredients used in the manufacturing of under body coating include fiberglass,ceramics,rubber,asphalt and silicone. Each has different properties in terms of heat resistance and retention,but all give protection against the elements and damage.

In automobile coating processes has coatings with thickness near 100-140micrometer,this thickness implies an average of 9-16kg of paint used per automobile.modern automobile coating methods consists of five main steps.

PRETREATMENT:

Removes and cleans excess metal and forms an appropriate surface structure enabling bonding of a corrosion protection layer.

ELECTRODEPOSITION:

This step involves electrodeposition of the anti-corrosion or rust prevention layer.

SEALER COAT:

A Sealer like polyvinyle chlorite(PVC) is applied for anti-corrosion,elimination of water leaks and minimization of chipping and vibrational noise.

PRIMER COAT:

Primer is then applied to promote adhesion between the surface and the back coat.It also imparts a smoother surface for subsequent layers and has anti-chipping properties.

TOP COAT:

The topcoat that include a base coat and clear coat are applied,They provide surface properties that are sought after,including color,appearance,glass smoothness and weather resistance.

ADVANTAGES OF UNDERBODY COATING

• Its extents the BIW's build materials life and quality.
• Resists corrosion,prevent welded joints.
• Maintains car interior temperature in required level.
• Gives better look and finish.

DISADVANTAGES OF UNDERBODY COATING

• Increases the car body weight.
• In this process pretreatment method not followed properly,Its allows corrosion quickly.