BHAGIRATH COACH AND METAL FABRICATORS PVT. LTD.

TRANING PRESENTATION BY:

NEERAJ DESHMUKH B.TECH(MECH.)FINAL YEAR

ROLL NO: 3112623

COMPANY PROFILE:BCMF was started in the year 1975.

ISO 9001:2000 certificationBCMF is the only cargo body supplier of EICHER.Its deal with Truck Body, Coach Buses Body,

Luxury Passenger Buses Body, Container Bodies, Ambulances Body, Mobile Laboratories Body, Executive Coaches Body.

What is POWDER COATING ?Powder coating is a dry finishing process, using fine particles

of paint, which are electrostatically charged and sprayed onto a work piece.

Once the powder is applied, the part is cured, causing the powder to adhere to the surface.

The main advantage of using the powder coating process is the waste powder which is unused during the process can be collected back by morden powder collecting methods , thus helps to use this powder over and over again, which in turn makes the Powder coating process highly economical.

PRINCIPLE:Powder coating is based on Electrostatic

charging process.In Electrostatic powder coating particles with

opposite charges attract each other.When exiting the powder gun, the powder

particles are charged through the deposition of air ions. The resulting ionized powder particles, similar to the free ionized air particles, are attracted to all earthed objects. In practice, the earthed object is the work piece, thus the powder remains bonded to it.

Characteristics of Powder Metal PowderParticle Shape: The particle shape depends

largely on the method of powder manufacture. The shape may be special nodular, irregular, angular, and dendritic.

Particle Size: The particle size influences the control of porosity, compressibility and amount of shrinkage.

Flow Rate: It is the ability of powder to flow readily and confirm to the mould cavity. It determines the rate of production and economy.

Compressibility: It is defined as volume of initial powder to the volume of compact part. It depends on particle size, distribution and shape.

Apparent Density: It depends on particle size and is defined as the ratio of volume to weight of loosely fille.

Purity: Metal powders should be free from impurities as the impurities reduces the life of dies and effect sintering process.

Powder Constituents: 1. Resins are the key component of powder

coatings.2. Pigments are generally solid particulate

materials such as titanium dioxide or carbon black.

3. Extenders such as aluminum silicate are used to provide opacity and act as filler.

PROCESS:There are three steps in Powder coating

process.

(1) PRE TREATMENT PROCESS.

(2) POWDER COATING

(3) CURING

PRETREATMENT PROCESS:1. Degreasing.2. Water rinse.3. Derusting.4. Water rinse.5. Activation.6. Phosphating.7. Water rinse.8. Passivation.9. Drying.

DEGREASINGWATER RINSE WATER RINSE

WATER RINSE

WATER RINSE

DERUSTING DESCALING

ACTIVATIONPHOSPHATINGPASSIVATIONMATERIAL DRY

Sequence Process of (Pretreatment) Powder Coat:

Powder Coating by Spray gun:

The powder is applied with an electrostatic spray gun to a part that is at earth (or ground) potential. Before the powder is sent to the gun it is fluidized to separate the individual grains of powder and to improve the electrostatic charge that can be applied to the powder so that the powder flows more easily to the gun. Because the powder particles are electro statically charged, the powder wraps around to the back of the part as it passes by towards the air off take system.

CURING:When a thermosets powder is exposed to elevated

temperature, it begins to melt, flows out, and then chemically reacts to form a higher molecular weight polymer in a network-like structure. This curing process, called cross linking. Normally the powders cure at 200°C (390°F) in 10 minutes.

The equipment’s used for Powder Coating Are Powder Coating Booths, Coating Equipments, and Baking Oven & Material handling systems.

In which the work piece is going in to oven,

The temperature of the oven is 200*c.

The work piece is placed up to 20 min.

ADVANTAGES:No solvents are used. Over-spray (up to 98%) can be reused.More resistant to chipping, cracking, and

fading.Corrosion and chemical resistant.Coating does not run, drip, or sag.Thick coatings are easily done.Simple clean-up and maintenance.

DISADVANTAGE:Thin coatings are difficult to produceStorage and handling of the powder requires

special climate controlsColor matching is somewhat more difficultCure temperatures may be too high Difficult to coat sharp corners

CARGO BODY OF EICHER

PRODUCTION:First of all take:1. Raw material.2. Base frame assembly.3. Side assembly.4. Grinding and Final rework.

1.Raw Material 2. Base frame assembly 3. Side assembly 4. Grinding & Final Work

PAINT SHOPPaint application is one of the most demanding

aspects of automobile manufacturing. Not only does the paint coating protect the body surface, it also enhances visual appeal by sadding color and gloss – important selling points. The technology used must meet high expectations of quality and cost.

Primary measures at the outset are unable to prevent emissions, secondary measures are necessary to reduce them. Statutory regulations also require the careful use of valuable resources such as water, power and paint raw materials.

PROCESS:Degreasing : Solvent degreasing is a process in which a cleaning agent is

applied directly to the surface by spraying, brushing, or wiping. This process removes oil, grease, dirt, loose particles, and any other contaminants that may exist on the surface of the material.

Phosphating : Phosphate coatings are used on steel parts

for corrosion resistance, lubricity, or as a foundation for subsequent coatings or painting.

The main types of phosphate coatings are manganese, iron and zinc.Passivation: Passivation, in physical chemistry and engineering, refers

to a material becoming "passive," that is, being less affected by environmental factors such as air and water. Passivation involves a shielding outer-layer of base material, which can be applied as a microcoating, or oxidation which occurs spontaneously in nature.

Dry oven: After passing all pretreatment zones by

means of the conveyor system, residual humidity is eliminated in the dry off oven to make sure the adhesion of coming powder application. 

Sealant: Sealant is a substance used to block

the passage of fluids through the surface or joints or openings in materials, a type of mechanical seal.

Sealants are not adhesives but some have adhesive qualities and are called adhesive-sealants or structural sealants.

Paint booth: Primer is designed to adhere to surfaces

and to form a binding layer that is better prepared to receive the paint.

Metal hydroxides/oxides do not provide a solid surface for the paint to adhere to, and paint will come off in large flakes. Using a primer will provide extra insurance against such a scenario.

Baking oven: Baking may also be called as stoving.

during baking in liquid form achieves formation of continuous film. the extent of cross - linking during the reaction depends upon the ingredients of paint.

 

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