Paint damage, paint defects and environmental effects (original) (raw)
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Hidden Reason of Paint System Delamination
In many instances paints interlayers delamination is attributed either to environmental or to application reasons. The composition as well as the structure, including morphology are always given for granted. Extended interlayer delamination was observed on two huge structures (>50000m2 each) causing more than $10 M damages. Overcoating time, UV exposure, Solvent retention and other possible environmental possible causes were considered. However, a careful morphological analysis showed that substantial differences existed in terms of the resin to pigment ratio, the surfactants, the quality of pigments and fillers (dimensions, shape, wettability, reactivity, homogeneity of distribution…) with respect to the sample used to certify suitability of the systems to climatic conditions C4 – C5 (ISO12944). The need to avoid any either voluntary or casual modification in both PVC and the kind and size of pigments to be used should be made evident as well as shown in some paragr...
2013
This study presents an initial investigation into the surface characteristics of the uppermost paint layer of paintings, i.e., the finished final paint surface. The primary focus is on how to characterize differences in surface morphology between intact and damaged paint in order to understand how small local disruptions (primarily abrasion) at the very surface of otherwise intact paint affect the overall visual impression of a painting. To what extent does surface abrasion or the additive effect of small areas of surface abrasion interfere with our reading of the picture? When viewing a painting, a broad spectrum of the surface phenomena contributes to our perception (natural aging, such as color fading and shifts in color, discolored varnish, cracks, results of restorations, etc.). To better understand this phenomenon, differences between intact and abraded surface areas of the same paint layer were examined using a variety of analytical techniques (Figure 1). Gross abrasion that ...
Usually the home improvement job undertaken by the average person is painting and decorating. Very often, this is carried out by people with little or no past experience. These jobs are attempted for numerous reason one of the most common being an urgent need to get a coat of paint onto walls of a house just purchased or achieving good protective and decorative work. The most important are: selecting the correct paint for the job, using the most suitable tools, preparing surfaces and applying the paint. Failure to consider the first-two or inadequacies in surface preparation and application might result to some paint defects.
PAINTING PROCESS IMPROVEMENT FOR AUtomotive industry
A report is submitted in partial fulfillment of the requirements for the award of the degree of Bachelor of Mechanical Engineering with Automotive Engineering Faculty of Mechanical Engineering UNIVERSITI MALAYSIA PAHANG NOVEMBER 2008 ii
Paint blistering affects quality of finished products
Engineering Failure Analysis, 2018
Automotive painted components confront an almost limitless variety of environments and environmental assaults. The appearance (color, gloss, and texture) of the surface significantly affects a customer's perception of product quality. During the paint application process however, and later during car operation, numerous kinds of failures and/or paint damages can occur. A defective part from a car in warranty period with paint blisters was brought for investigations. Samples from defective part were taken, and then they were examined using optical microscopy and Fourier transform infrared spectroscopy (FTIR). A section of the part away from the blisters was excised and used as a reference. The black coating was analyzed in the reference area, on the rim of the part away from the blisters and on top of the coating covering the blisters. The result of the spectral subtraction revealed that benzyl benzoate was used inside of the car. Benzyl benzoate is used in topical medications, insect repellents, perfumes and cosmetics. As a proof of benzyl benzoate utilization inside of the car, a paint attack with benzyl benzoate was performed. The test revealed that, the part's failure was similar to that seen in the returned part from the car in warranty period.
Automotive Painting Technology
Springer eBooks, 2013
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Predicting Enamel Layer Defects in an Automotive Paint Shop
IEEE Access
The appearance of the painted surface of the vehicle is key in the quality that the automotive customer perceives. The assurance of this quality starts in the automotive paint shop and compromises the effectiveness of the painting process as every paint defect is reworked. This entails material and labour costs, reducing the efficiency of the process and affecting the competitiveness of the product. To improve the efficiency while guaranteeing the quality, predictive control rather than corrective must be implemented. In order to achieve this control, a predictive model of quality is needed. As a first step to generate said model, this article demonstrates the correlation between the variables of the enamel coating process and the quality of the paint film of the vehicle. As there are no available application examples in the industry, a procedure is proposed in which the necessary steps for the creation of an industrial data set and a predictive model of quality are defined. The procedure is tested in an automotive paint shop. As a result, relevant variables for the quality assurance are identified and the correlation between process variables and the resulting quality is verified, concluding that the implementation of predictive control in the process is feasible. INDEX TERMS Predictive modelling, automotive industry, manufacturing digitization, industrial data set.