AP-42, CH 6.4: Paint and Varnish
6.4PaintAndVarnish 6.4.1PaintManufacturing1 Themanufactureofpaintinvolvesthedispersionofacoloredoilorpigmentinavehicle, usuallyanoilorresin,followedbytheadditionofanorganicsolventforviscosityadjustment.Only thephysicalprocessesofweighing,mixing,grinding,tinting,thinning,andpackagingtakeplace.No chemicalreactionsareinvolved. Theseprocessestakeplaceinlargemixingtanksatapproximatelyroomtemperature. Theprimaryfactorsaffectingemissionsfrompaintmanufacturearecareinhandlingdry pigments,typesofsolventsused,andmixingtemperature.About1or2percentofthesolventislost evenunderwell-controlledconditions.Particulateemissionsamountto0.5to1.0percentofthe pigmenthandled. Afterburnerscanreduceemittedvolatileorganiccompounds(VOC)by99percentand particulatesbyabout90percent.Awatersprayandoilfiltersystemcanreduceparticulateemissions frompaintblendingby90percent. 6.4.2VarnishManufacturing1-3,5 Themanufactureofvarnishalsoinvolvesthemixingandblendingofvariousingredientsto produceawiderangeofproducts.Howeverinthiscase,chemicalreactionsareinitiatedbyheating. Varnishiscookedineitheropenorenclosedgas-firedkettlesforperiodsof4to16hoursat temperaturesof93to340°C(200to650°F). Varnishcookingemissions,largelyintheformofvolatileorganiccompounds,dependonthe cookingtemperaturesandtimes,thesolventused,thedegreeoftankenclosureandthetypeofair pollutioncontrolsused.Emissionsfromvarnishcookingrangefrom1to6percentoftheraw material. Toreduceorganiccompoundemissionsfromthemanufactureofpaintandvarnish,control techniquesincludecondensersand/oradsorbersonsolventhandlingoperations,andscrubbersand
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