tailieunhanh - Systems and processes manufacturing automotive body: Part 2

Systems and processes manufacturing automotive body: Part 2 present: discusses the automotive painting processes and its different steps; starting from the conditioning and cleaning, then the conversion and E-coating, followed by the spray-based painting processes. The final assembly area and the different processing applied. The mechanical joining and fastening practices are given in detail, explaining the different strategies that automotive OEMs use to ensure the right tension loads are achieved in their mechanical joints. The automotive manufacturing ecological aspects, from the materials used and their utilization in addition to the energy expended in the manufacturing process. Use to plan the factory layout from the process-based, the product-based, and the cell-based layouts. The operational and strategic management aspects of automotive manufacturing. | 4 Automotive Painting Introduction The painting process applies the different protective layers needed to ensure that the BiW is corrosion-resistant. This includes not only the protective paint films on the vehicle shell but also the necessary under-body sealer PVC and wax applications. Also the painting process controls the final look of the vehicle shell through its color and gloss characteristics. The main layout of the paint line is shown in Figure which displays the different activities within the paint-lines. Immersion Coating Processes The first process in the painting sequence is the conditioning and cleaning of the BiW arriving from the body-weld line. The cleaning process is intended to clean and remove all the steel mill oils stamping lubricants and other welding sludge and contaminants. These contaminants not only affect the appearance of the applied paint films but also the paint layers adhesion and integrity because any surface contaminants affects the panels surface energy. The second step in the pretreatment process after cleaning is called the conditioning process which helps to promote the paint film adhesion and reduce the metal to paint reaction particularly with galvanized surfaces and finally improving the corrosion resistance more specifically the blister resistance. Metal surfaces constitute different contaminants with different chemistries such as the ones shown in Figure . The conditioning process is typically composed of the following functional steps cleaning rinsing The Automotive Body Manufacturing Systems and Processes Mohammed A. Omar 2011 John Wiley Sons Ltd. ISBN 978-0-470-97633-3 178 The Automotive Body Manufacturing Systems and Processes Figure Typical activities in a painting booth Process Oil Adsorbed Contaminants Hydroxide layer Metal Oxide Segregated Material Bulk Metal Figure The different layers of surfaces Automotive Painting 179 conditioning conversion coating rinsing post-treatment and de-ionized .