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A powder coating system efficiency chart Transfer efficiency 10 20 30 40 50 60 70 80 90 100 85 42.55 62.50 74.07 81.63 86.96 90.91 93.96 96.39 98.36 100.00 90 52.63 71.43 81.08 86.96 90.91 93.75 95.89 97.56 98.90 100.00 92 58.14 75.76 84.27 89.29 92.59 94.94 96.69 98.04 99.12 100.00 93 61.35 78.13 85.96 90.50 93.46 95.54 97.09 98.28 99.23 100.00 94 64.94 80.65 87.72 91.74 94.34 96.15 97.49 98.52 99.34 100.00 95 68.97 83.33 89.55 93.02 95.24 96.77 97.90 98.77 99.45 100.00 96 73.53 86.21 91.46 94.34 96.15 97.40 98.31 99.01 99.56 100.00 97 78.74 89.29 93.46 95.69 97.09 98.04 98.73 99.26 99.67 100.00 98 84.75 92.59 95.54 97.09 98.04 98.68 99.15 99.50 99.78 100.00 99 91.74 96.15 97.72 98.52 99.01 99.34 99.57 99.75 99.89 100.00 System efficiency = Source: Adapted with the kind permission of Nordson, Amherst, Ohio. 12 POWDER COATING, December 2016 R Reactive diluent. A viscosity re ducer for coatings that has low volatility and will become a permanent part of the coating through chemical reaction. Reactivity. The relative capacity of an atom, molecule, or radical to combine chem i cally with another atom, molecule, or radical. Resin. Film former; material (natural or synthetic) contained in varnishes, lac- quers, and paints. See also Polymer. S Sintering/blocking. The process by which a free-flowing powder softens and agglomerates. Specific gravity. An expression of the den- sity of a material. The ratio of the weight of a given volume of liquid or solid to the weight of an equal volume of water. T Theoretical coverage. The amount of area that can be covered with a given amount of powder coating at a defined average film thickness (often calculated for 1 mil, or 25 microns, and expressed as square feet per pound per mil). It can be determined through a mathematical for- mula containing a numerical constant, the specific gravity of the powder, and the average intended film thickness (often 1 mil). Terms such as mileage and theoret- ical mileage also are used. Thixotropes. Additives used to impart thixotropy to a coating. See Thixotropy. Thixotropy. Flow behavior in which vis- cosity is reduced by touch (agitation, stir- ring). Thixotropy is time dependent. With a thixotropic material, viscosity decreases with time at a given shear rate, then rebuilds with time when the shearing stops. See Thixotropes. U Ultraviolet-light-curable (UV cur- able). Ultraviolet light, not heat, is used to cause the chemical curing process. Upgraded resins. Resins that contain more than two epoxide groups; also called multifunctional resins. V Vinyl group. A group of atoms derived when one hydrogen atom is removed from ethylene. Viscosity. A measure of how much or how well a material flows under a specific set of test conditions. Reported in poise or pascal seconds for the polyesters. Higher value represents higher viscosity and lower flow. Definitions are a compilation from glossaries published with the following articles in Powder Coating: "Polyester resins—versatility leads to win- ning performance," by Carl J. Sullivan and Clayton C. Crawford, vol. 8, no. 5 (August 1997), p. 22. "A review of ultraviolet-curable powder coat- ings," by Shelby F. Thames and James W. Rawlins, vol. 7, no. 8 (Novem ber 1996), p. 21. "Thin-film powder coatings: Ad van ta ges to consider," by Bruno Fawer, vol. 7, no. 1 (February 1996), p. 43. "Acrylic resins for powder coatings: Cur rent generations and future trends," by Jos M.J. Verlaak, vol. 5, no. 3 (June 1994), p. 16. "Epoxy resins: A few facts will get you the fin- ish you need," by Robert Miller, vol. 4, no. 3 (June 1993), p. 24. Definitions in the preceding articles are from the authors and the following sources: L. Cecil and J. Beckwith. The Glossary of Standard Finishing Terminology. (Dear born, Mich.: Association for Fin ish ing Processes of the Society of Manu facturing Engineers, 1991). S. LeSota, ed., Coatings Encyclopedic Dictionary (Blue Bell, Pa.: Federation of Societies for Coatings Technology, 1995). T.A. Misev. Powder Coatings: Chemistry and Technology. (Chichester, England: John Wiley & Sons, 1991). F.C. Mish, ed.-in-chief, Webster's Ninth New Collegiate Dictionary, 9th ed. (Spring field, Mass.: Merriam-Webster, 1990). Oil and Colour Chemists' Association, Australia, Surface Coatings Volume I—Raw Materials and Their Usage, 2nd ed. (Randwick, Australia: TAFE Educa tional Books, 1983). S. Parker, ed., McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed. (New York: McGraw-Hill, 1989). G.L. Schneberger. Understanding Paint and Painting Processes. 4th ed. (Carol Stream, Ill.: Hitchcock Publishing, 1989). R.B. Seymour and C.E. Carraher, Giant Molecules (New York: John Wiley & Sons, Inc., 1990). POWDER COATING SYSTEM EFFICIENCY Reclaim (%) (%) Total amount of deposited powder Total amount of consumed powder

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