Question 4 hot yet a nswe re d Marked out of 1.00 Fag quescion A relatively new type of painting procedure is called powder coating. This new process is very different than traditional liquid paints. Liquid paints dissolve the coloured paint particles in a solvent. When the solvent evaporates, the paint particles are left behind and form the paint coating. Powder coating is much more like a photocopier or laser printer. The dry powdered plastic paint particles are given an electrostatic charge as they are blown out of the paint gun. The particles are then deposited on the charged or grounded target. Once the target is coated, it is baked which melts the powder to create a very even durable paint covering when cooled. There are two types of powder painting paint guns: the corona and the tribo. A corona paint gun works by using a negatively charged electrode with a potential difference of 30 kV to 100 M! at the nozzle where the powder particles come out. The target is given a positive charge. Corona paint guns are often used because they can paint large areas quickly with little wasted paint and good \"wrap around' effect. The one large disadvantage is that the corona guns experience faraday cage effect. A tribo gun often uses multiple smaller pipes with a Teflon liner. As the nylon paint powder goes through the Teflon lined pipes it picks up a positive charge before leaving the gun. The target is grounded. Tribo guns require specific tribo paint powders made from nylon. They are not as fast as corona guns but they don't suffer from faraday cage effect. Faraday cage effect occurs when powder paint particles will not enter small openings in a surface due to the electrostatic forces. Corona guns suffer this effect whereas tribo guns do not. small opening Faraday cage effect No Faraday cage effect with a corona gun with a tribo gun Compare and contrast how each gun charges the paint powder. (1 mark) \f\"\"5\"\" 6 Explain why electrostatic spraying of powdered paint is far more efficient in terms of the amount of ii.- ot yet answere d paint that attaches to the target than sprayed liquid paint. (2 marks] Markedoutof 2-00 % Paragraph V B .-" 55 E El 9.": E '1.\" Flag