POWDER COATING PRESENTATION.pptx

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NED University of Engineering & Technology Speaker: Arsalan Khalid (Batch 2007-08)

POWDER COATING

Polymer and Petrochemical Engineering

outlineIntroductionManufacturing ProcessPainting ProcessAdvantagesDisadvantagesTypes of PowderApplicationsReferencesWhat is Powder Coating?Powder Coating is a surface finishing technique that is applied as a free-flowing, dry powder.It is applied electrostatically and is then cured under heat to allow it to flow and form a "skin".

Powder coatings are solvent free paint used on furniture, window frames, radiators, pipes, and cars.It is Highly Durable and gives Superior Appearance, Mechanical, Corrosion, and Solvent Resistance Properties.

How is Powder Coating Manufactured?

How is Powder Coating Manufactured?The polymer granules are mixed with hardener, pigments and other powder ingredients in a mixer.The mixture is heated in an extruder.The extruded mixture is rolled flat, cooled and broken into small chips.The chips are milled and sieved to make a fine powder.

How is Powder Coating Applied?

How is Powder Coating Applied?Fine particles are fluidized in a feed hopper.Powder is vacuumed into the spray gun.A second burst of air increases the particle velocity.Particles are then charged by high velocity friction.Spray gun applies powder to the grounded workpiece.Coated part is then oven cured.How is Powder Coating Applied?Powder is applied with an electrostatic spray gun.The gun imparts a negative charge to the powder.

The powder attracts the part because part is grounded to the hanging device.The part is then placed in an oven, where it bakes at high temperature for a few minutes.

Advantages of powder coatingUp to 99% of powder overspray can be captured and recycled.No solvent to mix or recover.Near zero volatile organic compounds (VOC) emission.Less hazardous waste (Environmental friendly).Texture and structure appearance already built into the powder.Thicker coatings without runs or sags.Less Capital equipment and Operating costs.

Disadvantages of powder coatingAny non-conductive (e.g. plastic/wood) cannot me powder coated.All parts that are powder coated require some type of Curing.Cure temperatures may be too high.Thin coatings are difficult to produce.Color matching is somewhat more difficult.Uniformity of coating thickness is difficult to maintain.The item coated may not fit into the same space it came from.

No chemical reaction during curing process.Properties and Performance parameter:Limited color and gloss range.Only smooth finishes.Examples:PolyethylenePolypropylenePVC

1. Thermoplastics:Types of powder coating2. Thermosets:Chemical reaction occurs during curing process.Properties and Performance parameter:Unlimited color and gloss range.Unlimited surface appearance (e.g. Wrinkles, Textures).Examples:EpoxyPolyurethaneAcrylics

Types of powder coating

Applications

LPG CylinderGas HeaterShow PieceM.S Tube FurnitureHair Cutting ScissorWheel FrameReferencesCoating Methods, Powder Technology, Encyclopedia of Polymer Science and TechnologyA Brent Strong, Plastic Materials and Processinghttp:// www.wikipedia.comhttp://www.slideshare.nethttp:// www.power show.com

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