汽车涂料课程课件.ppt

1、2023年1月20日星期五汽车涂料课程汽车涂料课程汽车汽车OEM涂料介绍性课程涂料介绍性课程m课程的目的:帮助你更好的了解以下内容:l 汽车OEM涂料涂膜的基本组成；l 物理组成和物理性能的检验方法；l 汽车涂膜施工内容。汽车汽车OEM涂料介绍性课程涂料介绍性课程m 目的:什么是汽车涂料：其组成，固化条件，物理性质，涂层和涂膜的类型；涂膜的耐久性和评价；空气雾化喷涂设备和施工.；涂料涂膜缺陷原因和相应对策；使用汽车涂料时，必要的安全教育和预防措施。汽车汽车OEM涂料介绍性课程涂料介绍性课程m涂膜通常按照他们的作用分类或他们的分层区分：面漆；底漆；清漆；中涂；防石击；单组分或双组分。汽车汽车OE

2、M涂料介绍性课程涂料介绍性课程m涂膜时刻保护着您的爱车，同时给它带来无穷的魅力，以下是一个涂膜系统的功能：着色；遮盖；经久耐用；防腐蚀；防石击。汽车汽车OEM涂料介绍性课程涂料介绍性课程 汽车涂料的组成颜料助剂树脂溶剂涂料固化剂流变剂紫外线吸收剂汽车汽车OEM涂料介绍性课程涂料介绍性课程m基本组成成分：颜料(着色，物理性质)树脂(混合聚合物，提供强度和弹性)溶剂(降低涂料的粘度得以更易操作和施工)助剂(用以流平，流变，防止缺陷以及提高外观效果)这些因素是基于涂料的类型和目的而分类汽车汽车OEM涂料介绍性课程涂料介绍性课程m普通溶剂型底漆组成：成分成分 通常范围通常范围树脂(功能性丙烯酸)25-

3、30交联剂 (三聚氰胺)11-15颜料(着色、流变性及惰性)10-15溶剂 45-55助剂 1-3 汽车汽车OEM涂料介绍性课程涂料介绍性课程m普通水性底漆组成：成分成分 通常范围通常范围树脂(功能性丙烯酸)15-20交联剂 (三聚氰胺)6-15颜料(着色、流变性及惰性)6-15溶剂 10-15水 50-60助剂 1-3 汽车汽车OEM涂料介绍性课程涂料介绍性课程普通水性中涂组成：成分成分 通常范围通常范围树脂(功能性丙烯酸)15-20交联剂1(封闭异氰酸)2-5交联剂2(三聚氰胺)3-10颜料(着色、流变性及惰性)15-20溶剂 10-15水 40-50助剂 1-3 汽车汽车OEM涂料介绍性

4、课程涂料介绍性课程m普通清漆组成：组成组成 通常范围通常范围 树脂树脂(功能性丙烯酸功能性丙烯酸)35-40 交联剂交联剂1(封闭异氰酸封闭异氰酸)5-15 交联剂交联剂2(三聚氰胺三聚氰胺)10-15 颜料颜料(着色、流变性及惰性着色、流变性及惰性)1-3 溶剂溶剂 40-50 助剂助剂 3-5 汽车汽车OEM涂料介绍性课程涂料介绍性课程m颜料颜料：颜料按其固有的颜色和性质可以分为有机颜料和无机颜料；有机颜料通常是一些实验室开发出来的复杂分子；无机颜料是一些经过提炼的矿物；颜料进一步可以分为三种基本类别：色浆，金属/效果颜料和填料。颜料的浓度决定了涂料的遮盖力；颜料可以提高防腐能力。汽车汽车

5、OEM涂料介绍性课程涂料介绍性课程m典型的有机颜料：典型的有机颜料：二萘嵌苯红和橙 喹吖(二)酮红、紫和紫红 酞菁蓝和绿 靛蒽醌蓝-红 咔唑红-蓝（紫色）汽车汽车OEM涂料介绍性课程涂料介绍性课程m典型无机颜料：典型无机颜料：二氧化钛TiO2和氧化铁Fe2O3；硫酸钡；碳酸钙。汽车汽车OEM涂料介绍性课程涂料介绍性课程m 效果颜料可以是无机的，有机或两者的结合物；效果颜料可以是无机的，有机或两者的结合物；铝粉 着色铝粉 云母 包裹二氧化钛的吸收云母 Glass Flake 透明晶体 Graphitan汽车汽车OEM涂料介绍性课程涂料介绍性课程汽车涂料树脂：定义:由特定单体（构件块）合成，能达到

6、涂膜所需之性质的聚合物；用途:固化过程中反应涂覆系统的主体，这些聚合物给予涂膜的许多物理性质。汽车汽车OEM涂料介绍性课程涂料介绍性课程汽车涂料树脂：物理性质(树脂决定的）：耐久性 弹性 防石击性 抗溶剂性 硬度 附着性汽车汽车OEM涂料介绍性课程涂料介绍性课程汽车涂料树脂的类型：热固型 热塑型 聚脂 聚亚安酯/氨基甲酸盐 还氧树脂 丙烯酸 三聚氰胺甲醛 混合体 汽车汽车OEM涂料介绍性课程涂料介绍性课程m聚脂具有多种构造：三种重要分类：线性：单体聚合成的直长链；树型：链上带有分支的线性聚合物；交叉型:也被称作网状聚合物。几个分子链上几个位置发生交联形成了互相连接的分子聚合物矩阵。汽车汽车OE

7、M涂料介绍性课程涂料介绍性课程m聚脂具有多种构造：经过交联反应的聚合物被称作热硬化性聚合物；未经过交联反应的聚合物被称作热塑性聚合物；当加热或接触溶剂时，这些聚合物会变柔及再溶解。汽车汽车OEM涂料介绍性课程涂料介绍性课程汽车涂料树脂的类型：热硬化性(瓷漆)存在催化剂及加热的情况下，树脂分子与固化剂（交联剂）发生交联反应 热塑性(漆)溶剂挥发而形成干燥的涂膜，不存在化学反应或交联固化涂膜干涂膜汽车汽车OEM涂料介绍性课程涂料介绍性课程m聚脂具有多种构造：玻璃转化温度(Tg):在此温度下热膨胀系数上升。Tg 是部分聚合物还具有一定流动性的最低的温度，因为物质的能量增加（加热），分子中的原子会发生

8、振荡。汽车汽车OEM涂料介绍性课程涂料介绍性课程m聚合物的机械性能聚合物涂膜的机械性能（线性或交叉型的）依赖于很多因素，下面是这些因素中的一部分：交联部分的长度或聚合物的分子量；树脂或聚合物矩阵的Tg（即固化过程的前后）；支链，如果支链的聚合物主体是几个原子，长的及柔软的，则会导致整个树脂矩阵Tg的降低；交联密度，高的交联密度能使涂膜更坚硬，更坚韧。丙烯酸丙烯酸和三聚氰胺的反应和三聚氰胺的反应丙烯酸丙烯酸和和异氰酸异氰酸的反应的反应Ureclear Chemistry羟基羟基+环氧的反应环氧的反应汽车汽车OEM涂料介绍性课程涂料介绍性课程溶剂定义：溶剂是一混合物，在常温常压下一般为液态；它们可

9、以溶解其他物质，且被溶剂物不起化学变化。汽车汽车OEM涂料介绍性课程涂料介绍性课程溶剂用途：溶剂用来降低涂料的粘度，达到施工的需要。粘度的降低增强涂料的雾化性能，提升流平性和外观。小心选择一个溶剂组是控制涂膜缺陷的必要手段，溶剂的选择能影响流平、桔皮、干喷、流挂、气泡、和整体外观。汽车汽车OEM涂料介绍性课程涂料介绍性课程溶剂溶剂的关键因素:挥发速率 极性、非极性 对闪点的影响 HAPs compliance 气味 电阻系数汽车汽车OEM涂料介绍性课程涂料介绍性课程 溶剂类型：酮类 醇类 二醇及醚类 酯类 水 ORRROHHORORH2OCH3COORR=烷基:甲基 CH3乙基 CH2CH3丙

10、基 CH2CH2CH3丁基Ch2CH2CH2CH3丙基CH2CH2CH2CH2CH3汽车汽车OEM涂料介绍性课程涂料介绍性课程助剂 改变涂膜性质的化合物 它们的含量通常很低 它们可以提高涂料系统的关键性能 汽车汽车OEM涂料介绍性课程涂料介绍性课程助剂:用途:助剂浓度通常很低。它们可以提高相容性、流动/流平、铝粉定位、修补附着力、砂痕、湿度敏感性、气泡敏感性及缩孔的消除 汽车汽车OEM涂料介绍性课程涂料介绍性课程流动及表面助剂：定义：可以改变涂膜流动性质的化合物。用途：这些助剂通常的浓度非常低。它们被用来提高超喷的相容性、涂膜的流动和流平、铝粉的定位（金属控制）、湿膜特性、修补附着性、磨痕、最

11、小湿度敏感性、气泡和缩孔特性。汽车汽车OEM涂料介绍性课程涂料介绍性课程催化剂定义：催化剂引发化学转变，但它不是永久的和树脂体系结合用途：催化剂的存在可以促使一个化学固化/反应在一个较低的温度和有效的反应时间内发生。有几种催化剂，封闭和未封闭，有机和无机，每一种催化剂的选择都是基于特定的需求。汽车汽车OEM涂料介绍性课程涂料介绍性课程流变学定义：流变学是关于物质流动和变形的科学。流变控制剂(RCAs)是能改变或调整湿膜流动性的化合物。用途：RCAs 用于提高抗流挂性和金属控制,同时最小化再溶解性和磨痕 汽车汽车OEM涂料介绍性课程涂料介绍性课程流变学典型的RCAs存在两种状态.一，当它们被附加

12、能量（如在循环系统中或在涂装雾化过程中），或低浓度（在溶剂挥发前）时，它们是低粘度的流体；二，在能量消失和喷涂后溶剂挥发的时候，它们就处于高粘度的状态。汽车汽车OEM涂料介绍性课程涂料介绍性课程紫外线吸收剂(UVAs)定义：对太阳光能量敏感的化合物。用途：紫外线吸收剂吸收太阳光的能量（附带紫外线），再通过对涂膜无害的方式释放它，紫外线吸收剂能大大提高涂膜的耐久性。汽车汽车OEM涂料介绍性课程涂料介绍性课程Hindered Amine Light Stabilizers(HALS)Definition:HALS are free radical scavengers and through th

13、is processthey are used to protects the polymer matrix.They do not absorb UVradiation.Purpose:HALS are used as additives to capture binder and/or impuritygenerated free radicals.When HALS react with free radicals they gothrough a repeating cyclic mechanism,within the cured paint film,tostabilize the

14、 polymer matrix.Introductory Automotive OEM Paint CoursemSelect paint film properties Wetting Adhesion Corrosion Cure WeatheringIntroductory Automotive OEM Paint CoursemTo promote good adhesion,the coating must be capable of:Wetting the previous layer or substrate surface(mechanical adhesion).Formin

15、g chemical bonds between the coating layers(chemical adhesion).Introductory Automotive OEM Paint CoursemWettingDefinition:Wetting is the intimate contact of a fluid with a solid surface.Purpose:To contribute to the adhesion properties of the system.It isnecessary for a coating system to wet the subs

16、trate to obtain aninteraction between a coating material and a substrate.Introductory Automotive OEM Paint CoursemAdhesionDefinition:Adhesion is the phenomenon by which one material isattached to another by means of surface attraction.It is a very complexphenomena relating to the physical effects an

17、d chemical reactions at theinterface.Purpose:A bond(mechanical and chemical)between the paint systemand substrate to protect and offer appearance qualities.Introductory Automotive OEM Paint CourseCoatingMechanicalCoatingSurface Mechanics of AdhesionBulk SubstrateIntroductory Automotive OEM Paint Cou

18、rseCoatingChemicalCoatingSurface Mechanics of AdhesionBulk SubstrateOHOHOHOHOHOHIntroductory Automotive OEM Paint CoursemHow is paint cured?Hot air(convection)Infrared radiation Electron beams Ultraviolet radiation Catalysts Vapor cureIntroductory Automotive OEM Paint Coursem Physical Constants Soli

19、ds(weight&volume)Wt/gal(density)Viscosity Voc HAPs level Odor Pigment/Binder%Waterm Physical Properties Film thickness Color Gloss DOI(distinctness of image)Hardness Adhesion Humidity Resistance Chemical Resistance Impact Resistance Corrosion ResistanceTest Methods for Automotive CoatingsIntroductor

20、y Automotive OEM Paint CoursemApplication Techniques Hand sprayl siphonl pressure pot.Electrostaticl Hand Gunl Bell Automation equipmentl Conveyorsl Robotsl reciprocatorsIntroductory Automotive OEM Paint Course Atomization Air pressure Fluid pressure Fan shape or pattern Triggering Stroke Passes Num

21、ber of coats Gun speed Heeling and toeing Film build Flash time Overlapping Over spraymTerms Commonly used during Paint Application:Introductory Automotive OEM Paint Course Mottle Telegraphing Gloss Distinctness of image Strike-in Protrusion Dry spray Dirt Craters/Fisheyes Sags/runs Blistering Chalk

22、ing Orange peel Liftingm Appearance Terms Commonly used in Paint Application:Introductory Automotive OEM Paint Course Fluid viscosity Air pressure Fan Pattern and width(overlap percentage)Fluid velocity or fluid pressure Fluid flow rate Distance of application equipment to target Target speed(distan

23、ce/time)Ambient air temperature Surface temperature Ambient air velocity(side versus down draft booth design)Stroke speed over the working surfacem Check List Of Spray Variables Used Before Paint Application:Introductory Automotive OEM Paint CourseBasecoatBasecoat Clearcoat is a coating system where

24、in a highly pigmented color(base)is applied at relatively thin film builds(0.5 0.7 mils)and prior to baking is coated with a non-pigmented clear coat at a more typical film build(1.8 2.0 mils).The system is then cured to a high gloss,extremely durable enamel finish.PrimerClearcoatBasecoatElectrocoat

25、SubstrateClearcoatIntroductory Automotive OEM Paint CourseBasecoatPrimerClearcoatBasecoatElectrocoatSubstrateClearcoatBasecoatClearcoatIn-Line Repair(High Bake):when necessary the basecoat/clearcoatfilm may be repaired on line using the same material that was used in the high bake application.Introd

26、uctory Automotive OEM Paint CourseBasecoatPrimerClearcoatBasecoatElectrocoatSubstrateClearcoatBasecoatClearcoatFinal Repair(Low Bake):The material used in low bake repair is the samematerial that is used in the high bake process,but includes the addition of a catalyst.The incorporation of a catalyst

27、s allows the film to be cured at 20 minutes at 180oF.Introductory Automotive OEM Paint CourseBasecoatPrimerClearcoatBasecoatElectrocoatSubstrateClearcoatRedissolvingIntroductory Automotive OEM Paint CourseBasecoatPrimerClearcoatBasecoatElectrocoatSubstrateClearcoatProtrusion and MottleIntroductory A

28、utomotive OEM Paint CoursePrimerBasecoatElectrocoatSubstrateClearcoatDry or Rough SprayIntroductory Automotive OEM Paint CoursemPaint defects causes and corrective actions Craters Orange peel Dry spray Pop&Solvent boil Mottling,Floating and Flooding Sag&RunsPaint Defects Causes and Corrective Action

29、sCraters:Craters are circular recesses in the paint film.Causes are mainly due tooil,grease,wax and silicon residue.Causes:Incorrect use of paint additives.Unsuitable cleaning agents.Contaminated air from other work areas(polishes,oil,fine dust etc).Marks from clothing,rubber gloves,skin and hair lo

30、tions.Over spray paint from preceding or following process.Oil in compressed air.Poor cleaning of surface.Paint Defects Causes and Corrective ActionsOrange Peel:Poor surface texture of the painted surface similar to the texture of an orangeskin(a dimpled appearance).Causes:Spray gun held too far fro

31、m surface of the object.Spray pressure too low(poor atomization).Paint film too thin.Solvent too fast.Viscosity of paint too high.Spray nozzle too small.Flash-off time too long between coats.Dry spray application technique.Paint Defects Causes and Corrective ActionsPop/Solvent Boil:Blister like surf

32、ace defects due to solvent entrapment in the surface of the paintfilm.Causes:Film applied too thick.Flash off time between individual paint coats too short.Flash off time before baking too short.Too fast of heat-up rate.Solvent selection too fast,use a slower evaporating reducing solvent.Viscosity t

33、oo high.Air pressure too low.Paint Defects Causes and Corrective ActionsMottling/Floating/Flooding:Spots or strips of light and dark patches(blotchy)seen in a metallic coating.Causes:Uneven spray application.Flash-off between coats or prior to application of clearcoat too short.Color coat applied to

34、o thin.Spray viscosity too high causing wet films.Atomization pressure too low.Fan on spray gun too narrow.Spray gun too close to the unit.Overlap of previous gun stroke improper.Paint Defects Causes and Corrective ActionsSag/Runs:Vertical streaks of paint.These can be beads,droplets,larger globules

35、 or Curtain effects in the paint film.Causes:Viscosity too low(too thin).Solvent blend too slow evaporating.Paint or object to be painted too cold.Paint applied too thick.Flash-off time too short.Spray gun held too close to the object.Low atomizing pressure.Film thickness too high.Insufficient flash time between coats.