Challenge

Underbody Coating

SShubhangkar Rakesh Bongale4 Nov 2022

Under-Body coating is a process which protects the body of the car which is highly exposed to external atmosphere other that any other section of car.

Right now I will explain 11 Tank process.It is usually done on metals & aluminium. It is a part cleaning process usually done before application of powder coat on the metal.

Overview explanation

TANK-1(KOD) Knock of Degreasing (Cold Process)

Purpose : To remove oil particles with Ambient Temperature.

TANK-2 Degreasing (Hot Process)

Purpose: To remove oily surface with (70)`degree.

(TANK-3) & (TANK-4) water tank (RO water)(Cold Process)

Purpose: To wash off excess chemicals from above process from the part.

TANK-5 (Derusting) (Cold process)

Purpose: in this tank as per chemical nature removal of all rusted particles from the component.

(TANK-6 & TANK-7) water tank (RO water)(Cold Process)

Purpose: To wash off excess chemical from the process and make component process for next procesess.

TANK-8 (Surface activations for phosphating)(Cold process)

Purpose: To provide smooth surface for phosphating.

TANK-9 (Phosphating) (Cold process)

Purpose: To slow down aging of the component & to avoid rusting.

TANK-10 (Water wash)

TANK-11 (Passivation) (Hot process)

Purpose: To make component smooth & dry,clean.

DETAILED EXPLANATION

(TANK-1) KOD Knock of degreasing (Cold process)

Purpose:To remove oil particles within Ambient Temperature.

Chemical used:Phosclean 102*

Properties of Chemical:It is an excellent product of degreasing with application on variety of surface like zinc,aluminium & steel.

: It can be used both at ambient & higher temperature.

(TANK-2) Degreasing (Hot process)

Purpose:To remove oily surface with temperture in hot dip (70`degree`).

To remove all oily surface as in hot temperature oil (less dense) it will float above water.

(TANK-3) & (TANK-4) (RO water): To wash off excess oil particles from the surface & prepare the surface for other process.

(TANK-5) Derusting

Purpose:In this as per chemical nature remove all rusted particles from the component

Chemical used:(Rustokik 163)

Properties of Chemical:excellent efficiency for derusting.

:does not emit fumes.

:excellent deruster to get best phosphate coating.

:can be used in ambient temperature & hot conditions.

(TANK-6) & (TANK-7) (RO water):same as (TANK-3) & (TANK-4)

(TANK-8) Surface Activations

Purpose: Activations for phosphating with smooth surface.

Chemical used:(Crystofix 317)

Properties of Chemical:It is an excellent product to promote crystalline phosphate coating.

:Increasing the efficiency of phosphating by producing uniform phosphate coating.

:Versatile applications can be used in hot & cold conditions, also in spray method.

(TANK-9)Phosphating Coat

Purpose:To slow aging.

:To avoid rusting.

Chemical used:(Phoschem 197)

Properties of Chemical:An excellent nitrate,nitrite accelerated tricationic phophating chemical for hot dip process for M.S (Mild steel)

:Produces extra smooth, compact phosphate coating on M.S surface.

:It impart high corrosion resistance property to the metal surface.

:Produces excellent base for subsequent conventional painting & powder coating.

(TANK-10):Water wash

(TANK-11):Passivation (hot process)

Purpose:To produce a component smooth & dry,clean finish.

Chemical used:(Phosbond 312)

Properties of Chemical :Free from chromium & phosphate.

:It improves corrosion resistance property of dried phosphated surface.

:Reduce the risk of paint blistering.

TYPES OF COATS

*EP(Epoxy Polyester) usually indoor purpose.

*PP(Pure Polyester) usually outdoor purpose.

*SG(Semi glossy) according to requirement.

After the finishining of 11 tank process. Powder is applied on the component with help of electrostatic gun (blower) . The gun works on the prinicipal of electrostatic. Negatively charged particles (compoenent) and powder positively charged (powder) attracts towards each other.

In this the earthing valve must somewhere around 1M ohm for the streamline flow of powder particles on the component.

Then this parts are send to oven for the final stage

PICS OF FOLLOWING TANKS AND PAINT BOOTH ARE ATTACTED BELOW.

TANK 1