1 / 14

Presented By:

Powder Coating. Presented By:. Sarah Bennett. Jennifer Erle. Amberlee French. Josh Hamilton. John Schmitt. What is Powder Coating?. Powder coating is a dry finishing process, using fine particles of paint, which are electrostatically charged and sprayed onto a workpiece.

ciara
Download Presentation

Presented By:

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Powder Coating Presented By: Sarah Bennett Jennifer Erle Amberlee French Josh Hamilton John Schmitt

  2. What is Powder Coating? • Powder coating is a dry finishing process, using fine particles of paint, which are electrostatically charged and sprayed onto a workpiece. • Once the powder is applied, the part is cured, causing the powder to adhere to the surface.

  3. 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 Painting Process

  4. Electrostatic Spray System Specifications: • Particle Size Range: 10 μm to 30 μm • Bulk Particle Density: 1.5 x 103 kg/(m3) • Fluid (Air) Density: 1.177 kg/(m3) • Fluid (Air) Viscosity: 1.85 x 10-5 kg/(m·s)

  5. Fluidized Bed Parameters • Dimensions: 0.4m x 0.4m x 0.4m • Bed dimensions based on 50 lbs of powder • Pick-Up Tube Diameter: D =0.02 m • Fluidization of the particles prevents clogging

  6. 1) Terminal velocity for the smallest particle size : vt = 4.41×10-3 m/s • 2) Reynold’s number : Re = 2.81×10-3 • 3) Volume fraction of the powder particles for minimum fluidization : w = 0.41 • 4) Velocity in the pick-up tube : vtube = 48.52 m/s Fluidized Bed Calculations

  7. Volume Flow Rate Calculations • The volume flow rate at the tip of the gun was tabulated: vpowder = 250 m/s Aguntip = 3.142×10-4 m2 Vguntip = 0.079 m3/s • The second burst of compressed air volume flow rate was calculated: V2ndburst =0.063 m3/s

  8. Tribostatic Gun Layout

  9. Curing Process • Oven temperature: 300 °F • Time for complete cure: 20 minutes • Curing causes a chemical reaction that bonds the powder coating to the workpiece.

  10. Why Use Powder Coating? • Higher Quality • Extremely Durable • Environmentally Friendly • Cost Efficient

  11. 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 Advantages

  12. Disadvantages • Thin coatings are difficult to produce • Storage and handling of the powder requires special climate controls • Color matching is somewhat more difficult • Cure temperatures may be too high • Difficult to coat sharp corners

  13. Conclusion • Key concepts involved in powder coating: • Fluidized Bed • Mass Balance • Bernoulli Equation • Stoke’s Law • Specific calculated properties: • Terminal velocity in fluidized bed • Velocity in pick-up tube • Volume flow rate of second burst of air

  14. Powder Coating Questions ? Presented By: Sarah Bennett Jennifer Erle Amberlee French Josh Hamilton John Schmitt

More Related