汽车车身涂装的质量检验

车身涂装质量除直接影响汽车的防锈蚀性能、外观性能,还影响其制造成本。因此,对汽车涂装质量进行检验是汽车检验中一项重要内容。本文全面介绍了汽车涂装质量的检测方法;车身电泳漆膜现场常用的质量检测方法;车身中涂和面漆涂膜现场常用的质量检测方法;以及新车、在用车及乘用车车身涂装后的检验方法。     

导读

汽车涂装起到防腐蚀、保护和装饰的效果,涂装弊病影响汽车的防腐性能和外观,本期针对汽车涂装弊病原因分析及解决进行重点报道邓烈雄的"电泳漆膜缩孔案例分析"阐述了调查和分析产生电泳漆膜缩孔的原因及解决问题的整个过程田伟东的"车架涂膜阶梯纹缺陷的分析与工艺控制"分析了短车架电泳涂装线车架涂膜阶梯纹弊病的成因,结合涂装生产线的实际情况,从涂装工艺和设备方面详细阐述了车架涂膜阶梯纹缺陷的形成及工艺控制。陆岩的"车身面漆异色颗粒问题的     

汽车车身涂装的质量检验

介绍了汽车涂装前处理质量的检测方法、车身电泳漆膜现场常用的质量检测方法、车身中涂和面漆涂膜现场常用的质量检测方法及新车身涂装后的检验。对常见漆膜弊病的原因和应对措施进行了叙述。     

涂装前处理电泳降低用水量的方法及控制

电泳涂装时,车身内外表面钣金需要无油、无锈、无明显杂质,否则会直接影响电泳漆膜质量.为保证车身表面有良好的外观质量,涂装前处理和电泳过程中,均会采用大量的水对车身进行冲洗,因此涂装前处理、电泳成为汽车制造过程中用水最多的工序.本文主要针对降低自动葫芦输送设备涂装生产用水量的方法及控制进行研究,减少了涂装废水的排放.     

阴极电泳漆膜粗糙的原因与防治

阴极电泳涂装生产线出现电泳漆膜外观粗糙、膜增厚等问题，调整电泳工艺参数不能明显改善和防治，漆膜质量继续恶化；经分析发现电泳系统滋长了细菌，经杀菌处理后，质量恢复正常，面漆外观质量水平得到提高。     

电泳颗粒问题的分析及解决

分析了白车身洁净度、磷化槽液、电泳槽液及前处理电泳设备运行状态对电泳颗粒的影响,并提出相应的解决措施,进而确保水性紧凑型工艺的面漆漆膜外观。     

车架电泳漆膜表面粗糙问题分析与改善

电泳涂装产品性能的好坏最终通过电泳漆膜性能体现,因此在电泳涂装结束后需要对涂膜各项性能进行检测以验证漆膜品质。车架电泳涂装结束后,现场需要对电泳涂膜膜厚、附着力、外观、光泽等性能进行检测,电泳漆膜的表面粗糙问题直接影响产品外观。本文通过气相色谱、SEM等检测手段,对车架电泳漆膜表面粗糙问题进行分析,找到电泳漆膜表面粗糙的原因并提出相应的解决措施。     

车身涂装现场分部的节能方法

从重点设备、维持设备、设备管理等方面介绍了车身涂装现场分部的节能方法,包括改进前处理和电泳各水泵的生产方式以及电泳烘干炉、面漆烘干炉和面漆空调的生产方式,改进空压机的空气管路,提升生产节拍,等等.     

卡车用水性聚氨酯涂料的应用研究

探讨了水性聚氨酯(WPU)技术在原厂漆(OEM)卡车涂装领域的应用。基于水性羟基丙烯酸树脂和封闭型亲水性聚异氰酸酯,研发了卡车用WPU单涂层OEM面漆。测试结果表明,WPU涂层比水性丙烯酸氨基涂层具有更佳的外观和漆膜性能。     

浅谈3C2B工艺调试转量产过程的外观优化

某基地3C2B工艺的车型在由小批量调试逐步转为量产的过程中,为确保生产节拍,取消了中涂后的整体立面打磨工艺,并通过降低白车身粗糙度和白车身带屑量、降低电泳粗糙度及打磨点、适当提高闪干脱水率、调整中面漆的升温速率、细化喷涂轨迹、优化中涂和清漆的膜厚均一性等措施,进行了外观优化。     

溶剂及施工工艺对3C1B水性面漆外观影响研究

水性 3C1B（三涂一烘）工艺是以湿碰湿的方式喷涂水性中涂、水性面漆和清漆,并一次性烘干的工艺,可以显著降低能源损耗,提高生产效率。涂层外观是评价涂料质量和涂装效果的重要指标之一,而湿碰湿工艺的这种特殊的施工方式对涂层的外观表现更为敏感。本文以水性白实色涂料为例,从中涂、面漆的材料配方及施工工艺等方面对水性 3C1B汽车涂料的外观改进进行了研究,并识别出了关键影响因素,结果表明：水性面漆对漆膜整体外观的影响大于中涂;配方的干湿及喷涂雾化后的干湿对漆膜流平、流挂等影响较大,进而会影响漆膜的外观表现。     

镜面涂装的探讨

阐述了近来兴起的涂装技术———镜面涂装。介绍了镜面涂装所用的涂料,从素材打磨、补土、补土后打磨、头道底漆、头道底漆打磨、中涂、中涂打磨、面涂、面涂打磨、抛光等方面详细讨论了镜面涂装工艺。     

Characterizing and improving performance properties of thin solid films produced by weatherable water-borne colloidal suspensions on bronze substrates

While the development and application for transparent protective coatings for metals continues and broadens, the use of these coatings on high-value outdoor bronze objects, such as statues and architectural elements, requires extensive testing before use. Recent efforts in coatings technology have produced high-performance water-borne latex dispersions containing polyacrylics and poly(vinylidene fluoride) (PVDF) targeting extended coating lifetimes and improved UV resistance. Our studies show that a two-layer polymer film with a solvent based primer (Paraloid™ B-44) and a high performance water-borne topcoat (Kynar Aquatec™ RC-10206) exhibits high impedance as measured by electrochemical impedance spectroscopy. Upon annealing, those films further increased in impedance, suggesting improved corrosion protection compared to unannealed films. When soaking in water, films that contained high loading levels of coalescing agent (Dipropylene glycol monomethyl ether, DPM) in the topcoat formulation resulted in a visible whitening of the basecoat and a decrease in coating resistance. Characterization of the whitened layer by FT-IR indicated the presence of coalescent in the basecoat, suggesting that coalescent migrated from the topcoat into the primer basecoat. Annealing studies were performed to reduce uptake and reverse or inhibit water whitening.     

Novel techniques to investigate the impact of cellulose esters on the rheological properties and appearance in automotive basecoat systems

The viscous response of a coating formulation changes over several orders of magnitude after application onto a substrate. Furthermore, the performance and application attributes for a refinish basecoat formulation are slightly different from those of an OEM basecoat. The absence of a high temperature baking step during the refinish process necessitates that the paint exhibit very good antisag behavior as well as quick ‘dry to touch’ without compromising the flow and leveling properties of the coating as it dries. As most paint formulations are multicomponent in nature, it is always a challenge to precisely measure the impact of specific formulation components on the collective performance attributes of the applied coating. In this work, the focus has been to develop novel techniques that can be used to demonstrate a more quantitative measure of some of the performance attributes that rheological additives like cellulose esters can provide to automotive coatings. A series of pigmented basecoat formulations were prepared which contained cellulose acetate butyrates (CABs) of varying molecular weights at different levels based on the total solids of the coating formulation. The nonvolatile content of the formulations was also varied. The viscoelastic behavior of a typical automotive basecoat formulation during the drying process was then investigated using a novel rheological technique. Complex viscosity data (including storage and loss moduli as well as tan delta) were determined as a function of drying time and then compared to the macroscopic properties typically associated with a coating film as it dries. Thermogravimetric analysis (TGA) was also used to correlate the rheology of the metallic basecoat formulations with drying behavior of the coating. The final appearance of the coating was investigated by several microscopic techniques such as Laser Scanning Confocal Microscopy, Scanning Electron Microscopy, Atomic Force Microscopy, and Surface Profilometery, and attempts were made to correlate bulk measurements like ‘flop index’ with the microstructure of the coating. Presented at the 2006 FutureCoat! conference, sponsored by the Federation of Societies for Coatings Technology, in New Orleans, LA, on November 1–3, 2006.     

乘用车金属闪光漆及其施工技术

介绍了金属闪光漆的成分特性及与普通漆的区别、金属闪光漆的配方、功能特性、品种;金属闪光漆的施工工艺;以及车身局部补涂、车身翻新的金属闪光漆施工方法;同时指出了金属漆漆膜的外观缺陷分析与防冶。     

工程机械驾驶室涂装颗粒分析与控制

电泳涂装质量分涂层内在特性指标和外观质量。外观质量直接体现涂装线的管理水平,而涂层表面颗粒的多少是涂膜质量的重要评价因素,也体现了整条线的综合水平。本文结合三一车身有限公司电泳涂装线实际情况,对驾驶室产品进行了颗粒缺陷采样分析,重点分析涂装颗粒的产生原因和采取的相应措施,缺陷发生率下降75％,改善效果显著。     

封堵件在重卡车架电泳加工中的应用

介绍了重卡车架电泳过程出现的“螺纹进漆”和“管梁周围漆膜气泡”问题,分析了这两类问题的产生原因,介绍了两类问题相应的解决措施,总结了工艺螺塞和封堵片的选型方法。为工艺人员更好地掌握涂装细节提供了参考。     

Effects of IR pre-curing conditions on wear resistance of metal flake powder coatings

Hybrid IR/convective oven baking of high quality industrial powder coatings is one of the most attractive method to achieve significant economic and process time savings. This method is based on two curing steps: at first, a pigmented decorative basecoat is electrostatically sprayed and, then, pre-cured with IR-radiation, secondly, a transparent protective topcoat is sprayed on the basecoat and the resulting bilayer coating is oven baked. The optimization of the IR pre-curing conditions and the correlation between the effect of polymerization degree of the basecoat and the wear resistance of the whole coating system are investigated. In particular, an experimental study in which the degree of chemical conversion of the pigmented basecoat, the overall coating morphology and its thermal, mechanical and tribological properties are analyzed in the light of IR-radiation time and power, has been carried out. Experimental results show that the intermediate range of curing time and IR power investigated leads to properly cured basecoats and subsequently to better morphological, mechanical and tribological behavior of the whole coating system. These results were also validated by comparison with the coatings cross-linked by the traditional two-step oven baking process.     

表面涂装层颜色色差的工艺研究

对各类工业产品外表涂装层色差问题做了大量的工艺研究,从原材料、烘烤温度,喷漆黏度、涂层厚度等方面分析了影响涂层色差的因素,确定了最佳施工工艺,使涂层外观颜色达到了基本一致,提高了产品质量和外观精度技术水平。     

电泳涂装工艺参数对铝型材涂膜质量的影响

针对自行开发合成的铝型材丙烯酸阳极电泳涂料,探讨了漆液固体含量、电泳电压、电泳时间、漆液pH、助溶剂等电泳涂装因素对涂膜外观和厚度的影响。