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We developed a simple lift-off process for producing colorful, flexible, and lightweight Cu(In,Ga)Se2 (CIGS) solar cells. The developed lift-off process consists of three steps: first, attaching a plastic film on a CIGS/glass solar cell at the temperature of around 100 °C; second, scribing the cell to the desired area/shape after cooling down; and finally, a back contact is deposited on detached layers. The major advantage of the lift-off process is that the CIGS layer can be grown under high temperature, which is in contrast to the direct growth of CIGS cells on plastic films. Our measurements show that the fabricated lift-off cells have nearly identical performance compared to that of the cell before the lift-off process, suggesting the validity of the developed lift-off process for producing flexible and lightweight CIGS solar cells. The colors were generated on the cells by coating the highly transparent automotive paint on the plastic films. The glass-flake pigments were found to exhibit bright, uniform, and solid appearance on the flexible CIGS solar cells with small output power reduction of less than 5% compared to the cells before the lift-off process for chromatic colors.

In the forensic examination of automotive paint, each layer of paint is analyzed individually by infrared (IR) spectroscopy. Laboratories in North America typically hand section each layer and present each separated layer to the spectrometer for analysis, which is time consuming. In addition, sampling too close to the boundary between adjacent layers can pose a problem as it produces an IR spectrum that is a mixture of the two layers. Not having a “pure” spectrum of each layer will prevent a meaningful comparison between each paint layer or in the situation of searching an automotive database will prevent the forensic paint examiner from developing an accurate hit list of potential suspects. These two problems can be addressed by collecting concatenated IR data from all paint layers in a single analysis by scanning across the cross sectioned layers of the paint sample using a FTIR imaging microscope. Decatenation of the IR data is achieved by multivariate curve resolution using a Varimax extended rotation to select the starting point (i.e., initial estimates of the reconstructed IR spectra of each layer) for the alternating least squares algorithm to obtain a pure IR spectrum of each automotive paint layer. Comparing the reconstructed IR spectrum of each layer against the IR spectral library of the PDQ database demonstrated that it is possible to identify the correct model of the vehicle from these reconstructed spectra. This imaging approach to IR analysis of automotive paint, not only saves time and eliminates the need to analyze each layer separately, but also ensures that the final spectrum of each layer is “pure” and not a mixture.

A comprehensive laboratory experimental study was conducted on the application of electroflotation in removal of paint from automotive paint system. In 40 min testing time and under 44 A/m2 current density, the total suspended solids (TSS) removal rates ranged from 90.39 to 97.43%. The first and second-order rate constants were developed. The kinetics of the TSS removal from the automotive paint wastewater was best described with the second-order rate constants. Two statistical methods were applied to identify the key factors for electroflotation performance among the Initial TSS Concentration, Current Density, water pH, Zeta Potential and Electrical Conductivity. It was confirmed that in both methods, the Initial TSS Concentration and Current Density were the most significant variables. Further, through Response Surface Methodology and Stepwise Regression analysis, equations of the removal rate of TSS vs reaction time and applied current density were produced for different wastewater samples.

Resumo Mesmo com a evolução considerável das técnicas de pintura automotiva nas últimas décadas, o para-choque é uma autopeça que ainda tem diversos problemas relacionados ao aspecto da sua superfície pintada. O objetivo deste artigo foi identificar os fatores de aplicação do verniz que interferem na intensidade do aspecto de casca de laranja em superfícies de para-choques pintados e propor uma combinação ótima dos fatores através da metodologia do projeto robusto. Na pesquisa realizada no setor de pintura automatizada de uma empresa de para-choques, o projeto robusto auxiliou na identificação das formas de variabilidade do processo de produção através da aplicação de um experimento e de técnicas estatísticas, de forma ágil e com pouco desperdício de material. O experimento testou várias combinações dos níveis dos fatores de aplicação do verniz (velocidade, vazão, rotação por minuto, alta tensão, ar modelador) em amostras de para-choques. A intensidade da casca de laranja em superfícies pintadas de verniz das amostras foi medida pelo equipamento Wave Scan, o qual fornece a leitura do comprimento de onda em função de duas medidas: Short Wave e Long Wave. Os principais resultados obtidos através da análise da variância da razão sinal ruído revelaram que os fatores que têm efeitos significativos no valor resposta do comprimento de onda Short Wave são: rotação por minuto, alta tensão além das interações vazão*alta tensão e velocidade*alta tensão. Já os fatores que afetaram significativamente o valor resposta do comprimento de onda Long Wave são: vazão, ar modelador, rotação por minuto, alta tensão e a interação velocidade*alta tensão. Como resultado da análise das médias do sinal ruído, foi apresentada neste trabalho a combinação ótima dos fatores: velocidade = 920 m/s; vazão = 160 mililitros/minuto; ar modelador = 180 bar; rotação = 90 rotações/minuto; alta tensão = 180 quilovolts. Abstract Even with the considerable development of techniques for automotive paint in recent decades, the bumper is a car part that still has many problems related to the aspect of its painted surface. This study aimed to identify the clear coat application factors that affect on the intensity of orange peel appearance on painted bumpers surfaces and offer an optimum design of factors through the robust design methodology. In this research conducted in automated paint sector of a bumper company, the robust design helped in the identification of variability cause in a production process by applying an experiment and statistical techniques, in an agile and with little waste material way. The experiment tested various combinations of levels of the clear coat application factors (speed, flow, revolution per minute, operation voltage, atomizing air pressure) in the bumper samples. The intensity of the orange peel on coated surfaces samples was measured by a Wave Scan device that provides the wavelength reading as a function of two measures: Long Wave and Short Wave. The main results obtained by variance analysis of noise signal ratio showed that the factors that have significant effects on the value of the Short Wave response wavelength are: revolution per minute, operation voltage and the interactions flow*operation voltage and speed*operation voltage. The factors that significantly affected the response value of the Long Wave wavelength are: flow, atomizing air pressure, revolution per minute, operation voltage and the interaction speed*operation voltage. As a result of analysis of the noise signal mean, it is presented the factors optimum design: speed = 920 m / s; flow = 160 ml/min; atomizing air pressure = 180 bar; revolution per minute = 90 revolutions / minute; operation voltage = 180 kilovolts.

Automotive paint evidence is one of the most significant forms of evidence obtained in automotive-related incidents. Therefore, the analysis of automotive paint evidence is imperative in forensic casework. Most analytical schemes for automotive paint characterization involve optical microscopy, followed by infrared spectroscopy and pyrolysis-gas chromatography mass spectrometry ( py-GCMS) if required. The main drawback with py-GCMS, aside from its destructive nature, is that this technique is relatively time intensive in comparison to other techniques. Direct analysis in real-time-time-of-flight mass spectrometry (DART-TOFMS) may provide an alternative to py-GCMS, as the rapidity of analysis and minimal sample preparation affords a significant advantage. In this study, automotive clear coats from four vehicles were characterized by DART-TOFMS and a standard py-GCMS protocol. Principal component analysis was utilized to interpret the resultant data and suggested the two techniques provided analogous sample discrimination. Moreover, in some instances DART-TOFMS was able to identify components not observed by py-GCMS and vice versa, which indicates that the two techniques may provide complementary information. Additionally, a thermal desorption/pyrolysis DART-TOFMS methodology was also evaluated to characterize the intact paint chips from the vehicles to ascertain if the linear temperature gradient provided additional discriminatory information. All the paint samples were able to be discriminated based on the distinctive thermal desorption plots afforded from this technique, which may also be utilized for sample discrimination. On the basis of the results, DART-TOFMS may provide an additional tool to the forensic paint examiner.

For the application of continuous fibre-reinforced thermoplastics in car body structures it has to be ensured that they can pass through the automotive paint shop. There are substantial chemical, hygroscopic and thermal impacts throughout this process that can affect the shape of such components. The aim of this study is to model the deformation behaviour of continuous fibre-reinforced thermoplastics under hygrothermal loading. Relaxation tests were performed to assess temperature-dependent and viscoelastic behaviour. Input parameters for temperature and moisture distribution were determined experimentally and computed using finite difference method. A straightforward approach based on classical laminate theory is presented that comprises anisotropic viscoelasticity as well as hygroscopic, thermal and polymer-chemical effects. The introduced phenomenological model was successfully used to describe the deformation of five different laminate layups both dry and fully saturated with moisture.

Four perylene pigments were identified in North American automobile original finishes (1974–2019) and the analysis of Perylene Red Y (C.I. Pigment Red 224) was described previously. Perylene Red Y was not a common automotive paint pigment and is no longer used much. The analysis of a second member of the perylene family, Perylene Maroon (C.I. Pigment Red 179), is discussed in this article, and to determine the commonality of its use, spectra of 143 red or maroon metallic original basecoats were examined. Based on this survey, Perylene Maroon was found to be the most common organic pigment used in these. A large number of different pigment combinations involving this perylene were also identified and representative spectra of some of these are presented to illustrate the wide diversity of infrared absorption patterns that result. The individual pigments composing these combinations can often be identified, and this information can be helpful for both classifying and identifying automotive finishes. For red or maroon metallic basecoats produced after the mid-1980s, red pearlescent pigments based on mica became widely used and their identification was discussed previously. More recently, comparable effect pigments using alumina substrates were introduced and the identification of red alumina-based pearlescent pigments is described in this report. Three very unusual automotive paint formulations were identified and their spectra are presented to aid in vehicle identification.

Localized sudden changes in the surface energy of a surface to be painted are commonly held responsible for causing paint craters. However, it is not necessarily an easy task to identify the material(s) that produced the defects. Automotive paint cratering, when it happens, often requires immediate identification of its causes because the product line may have to be shut down until the problem is solved. For the past 18 years, Surface Science Western has applied time-of-flight secondary ion mass spectrometry (ToF-SIMS), among other techniques, to help its clients in the automotive industry identify the chemicals responsible for producing paint craters. In this article, we demonstrate that ToF-SIMS is a unique and powerful technique in identifying the chemicals such as siloxane, fluorocarbons and fatty acids that are responsible for causing paint craters. We further show that the chemicals can be foreign contaminants, as well as segregation of additives in the paint systems, and even from contaminated solvents used in the paint. When the chemicals causing the paint craters can be identified by ToF-SIMS analysis, the automotive company can often track down the primary source and remove the root cause. As such, surface analysis and in particular ToF-SIMS is invaluable in understanding paint cratering for both the surface analysis research community and paint manufacturers and users. Copyright © 2017 John Wiley & Sons, Ltd.

In violent vehicular crimes, the damaged area of a vehicle is usually repainted artificially in order to conceal the evidence. Detecting and recovering the hidden sub-layer morphology of repainted ...

Spectroscopies have been widely used in forensic science to analyze fingerprints, bloodstains, paints, etc. Hyperspectral chemical imaging is a fast and non-destructive method that provides spatial and spectral chemical information of a particular specimen. Recently, researchers have evaluated the characterization of automotive paints using Principal Components Analysis (PCA) performed on infrared and Raman spectroscopies data. However, to date, there is no report concerning the discrimination power of such trace evidence using Hyperspectral Imaging Visible/Near Infrared Spectroscopy (HSI-UV/VIS/NIR). Therefore, this work evaluated the potential of this technique combined with PCA as a forensic approach to discriminate automotive paints. In total, 38 samples from twelve brands and a variety of colors were analyzed. HSI-UV/VIS/NIR data was acquired directly from the paint chip’s surfaces, which includes the basecoat and clear coat layers. PCA was individually performed in distinct color datasets and could discriminate 100% of the white, silver, red and grey samples collected from different brands or from the same manufacturer with different color/shades. Furthermore, the PCA reliability for the identification of similar paint chips was successfully tested using fragments of silver and grey samples collected from different vehicle sources with common brand, color and shade. In agreement with the literature, the automotive black paints presented a much lower discriminating power (62.5%) because the spectra did not provide enough reflectance suitable for differentiation. These new findings support the idea of using HSI-UV/VIS/NIR as a fast, easy and efficient alternative technique to other spectroscopies for accurate forensic assessment of automotive paints.

The color-batching problem is frequently raised in automotive paint shops. This paper focuses on the implementation issues in obtaining color-oriented batches of cars with selectivity banks prior to painting. Two batching strategies, conventional physical resequencing and integrated physical & virtual resequencing, are considered. A rule-based fill approach and a heuristic-based release approach are presented, which can be jointly utilized on a rolling horizon basis when the strategy of conventional resequencing is applied. Moreover, two virtual resequencing techniques are introduced, both of which can be individually integrated into physical resequencing while integrated resequencing is used. Computational experiments are carried out to evaluate the performance of the proposed strategies and approaches. It is shown that integrated resequencing can generally obtain noticeably better batching results than conventional resequencing. Additionally, the impact of several factors on color-batching, including bank configuration, WIP, and size of look-ahead area, are discussed.

Retrospective energy optimization in a continuous manufacturing environment, such as an automotive paint shop, is limited in scope. This is due to the difficulty in not having a negative impact on production speeds.Typically, energy projects target one of three types of improvement: business process change (for example, optimizing start-up times or reducing idle times); technical interventions (for example installing variable speed drives); or capital replacement (for example, installing more efficient motors).Out of the four main process activities in an automotive plant, up to 75% of the total plant's energy bill can be attributed to the paint shop.The quality of output in a paint shop, in terms of color matching and paint quality, needs to remain at a constant 100% - this means that there is an inspection process at each major activity.Besides the need for facility level ambient lighting, the need for high quality task lighting is critical to keep the quality of the painting process at the requ...

The ability to predict the weathering performance of the clearcoat system over a short period of time is essential for the design and development of coating production. Thus, the primary objective of the present study is to investigate whether it is possible to predict the weathering performance of an automotive paint system through determination of surface roughness, Ra, and micro-hardness before and after various weathering exposure times (0, 24, 168, 336, 504, 672 hours) and when employing two different detergent materials (house-use detergent and car wash detergent). The data were analysed using a pair-sample t-Test, with 0.05 level of significance. It was found that the total net of degradation in the clearcoat level during the first 24 hours was Ra ≈ 30.3 nm (for surface roughness) and 1.358 HV (for the μ-hardness) when using the house-use detergent. In contrast, it was found to be Ra ≈ 4.6 nm (for surface roughness) and 1.133 HV (for μ-hardness) when using the car wash detergent. Also, increased time of weathering (up to 672 hours) increases the Ra and μ-hardness values. It can therefore be concluded that the effect of house-use detergent was more severe than that of car wash detergent on the clearcoat system.

The infrared (IR) diamond cell technology is the main approach used for the identification of vehicles involved in hit-and-run cases. An alternative approach in its infancy is solid sampling electrothermal vaporization (ETV) coupled to inductively coupled plasma optical emission spectrometry (ICPOES) in combination with multivariate statistical tools. Unlike the IR diamond cell approach, ETV-ICPOES does not require the separation of paint layers, bulk analysis of 2 mg paint chips placed in graphite boats being performed after their insertion into the ETV furnace. A temperature program ultimately vaporizes the analytes that are immediately transported into the ICP where they undergo excitation and emit characteristic light. The peak areas of the resulting transient emission signals are then used for the discrimination of samples using linear discriminant analysis (LDA), which requires at least two samples per classification. The approach was applied to samples from different vehicles in two junkyards and resulted in correct matching of 25 samples for manufacturers using Ag, Al, Ca, Cr, Cu, Hg, Mg, Ni, Pb, Pt, S, Sn, Tl, W, and Zr, 26 samples for year of production using Ag, Al, B, Ba, Br, Ca, Ce, Cs, Ge, Hf, Hg, Mg, Si, Te, and Zn, and 31 samples for colour using Au, B, Ba, Ca, Cu, In, Mg, Ni, Pd, Se, V, W, and Zn. The robustness of the approach was demonstrated through correct identification of the manufacturer, year of production and colour of a rusted paint chip.

A special focus has recently been made on the enhancement of the mechano-tribological properties of the clearcoats commonly used in several industries such as the automotive manufacturing sectors. However, still further investigations are needed for the better understanding of the behavior of such clearcoats in different working conditions. The purpose of the current research was investigating the erosion resistance, adhesive strength, micro-hardness and weathering stability of the acrylic-based polyurethane nano-composites which were reinforced by precipitated and fumed nano-silica particles. To achieve this, Zeta Sizer, scanning electron microscope (SEM), X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR) analyses were used. Furthermore, a series of experimental tests including the adhesive strength, toughness, micro-hardness and erosion resistance were carried out to measure the mechanical response of the fabricated clearcoats. It was concluded that the nano-silica additives significantly improve the adhesive strength, and highly increase the micro-hardness as well as the erosion resistance. It is also found that the precipitated nano-silica is able to create an inexpensive, hard and tough coatings rendering it very durable against wear, weathering conditions, and, thus, can be potentially employed as a reinforcing filler and as a replacement to the fumed clearcoats that are usually much more expensive than the proposed reinforcement.

A prototype infrared (IR) library search system for the paint data query (PDQ) database has been further developed to determine the make, line and model of an automotive vehicle from the clear coat, surfacer-primer, and e-coat layers in an effort to improve discrimination capability in automotive paint comparisons involving intact paint chips. Search prefilters for the IR spectral library of PDQ were developed from the clear coat, surfacer-primer and e-coat layers for 1179 manufacturer paint systems within a limited production year range (2000–2006) to identify vehicle manufacturer (Ford, Chrysler, and General Motors). For each make (i.e., manufacturer), search prefilters were developed to identify the assembly plant of the vehicle using a hierarchical classification scheme. A cross correlation library search algorithm that performed both forward and backward searching was then used to identify the line and model of the vehicle from the truncated IR spectral library of PDQ identified by the search prefilters. Samples assigned to the same line and model by both a forward and backward search of the IR spectral data were always correctly matched, always correlated well on an individual basis to a specific library sample and were well represented in the truncated PDQ spectral library identified by the search prefilters. The performance of the prototype IR library searching system (search prefilters and cross-correlation library search algorithms) for the PDQ database was benchmarked against commercial library searching algorithms. Only the results for Ford are reported here.

The demanding requirements placed on industrial test equipment means that for terahertz sensing to be adopted in quality control sectors, the technology must not only be capable of providing the qualitative and/or quantitative information of interest, but to do so in a robust and reliable manner. Here, we report on some of the developments implemented to bridge this gap for terahertz sensing to be deployed into one such industrial production setting: coating thickness inspection in the automotive paint shop. This has allowed terahertz to provide feedback on paint film thicknesses, and thereby allow for greater control of the paint process. Application Readiness, as defined by key manufacturers, their distributors and integrators, has been achieved.

Laser-induced Breakdown Spectroscopy (LIBS) is considered a versatile, multi-elemental, non-contact, powerful atomic spectrometry method, which can provide elemental composition data for practically any sample in a virtually non-destructive sampling and without or minimal sample preparation. Considering the forensic science, LIBS aggregates important advantages, such as quickness of analysis, potential field portability, the ability to provide characteristic spectral fingerprint information for classification and/or identification purposes, and potential for the investigation of dangerous materials from a safe distance and/or in safe microscopic quantities. Several different LIBS applications can be considered as forensic analysis, such as fraud/adulteration detection, antiterrorism efforts, post-disaster activities, and crimes evidences. Considering these forensics interests, the LIBS technique has been applied successfully to elemental determination in paper and ink, drugs, gunshot residue, spent brass cartridges, soils, bones, glass, mortar, clay, blood, swine skeletal muscles, enriched uranium, automotive paint, cotton, human cremation ash, explosives, counterfeit products, and adulterated foods. Additionally, the analysis of hazardous materials of forensic interest can be performed at a safe distance from the material and non-contact material detection through standoff LIBS systems.

In this paper, a technique for the characterizing the complex permittivity of a thin layer of automotive paint at millimeter-wave frequencies based on the free-space reflection measurement technique is presented. The retrieval algorithm of the complex permittivity is based on fitting the measured reflection coefficient of a layer of paint backed by a flat metallic plate to the corresponding analytical reflection coefficient of a simple dielectric slab backed by perfect electric conductor. Details of the technique are presented along with validation and permittivity data of different types of paint material. A hybrid low-high frequency technique for measuring the permittivity, devoted for non-uniform paint thickness case, is also introduced.

Resumen En este trabajo, se caracterizó el color de lacas acrílicas blancas utilizadas para retocar pintura automotriz, mediante el espacio de color CIELab y el índice de blancura, utilizando el iluminante estándar D65 y el observador estándar a diez grados. A partir de tal información, fue posible reconocer las tendencias del color usado en este tipo de productos en el mercado nacional. Por otra parte, la aplicación de las técnicas quimiométricas de Análisis de Componentes Principales, Análisis de Grupos y Análisis Jerárquico, permitió reconocer semejanzas entre los colores observados, encontrando, entre otros, la mayor diferencia visual en la laca de blanco aperlado. Por otro lado, la laca de blanco Alaska de Mazda y la de blanco universal de Nissan fueron las más parecidas. También se concluye que el análisis cromático y el quimiométrico de datos espectrales fueron complementarios, por lo que se recomiendan ambos en el nivel de control de calidad. Abstract The color of white acrylic lacquers utilized to touch up automotive paint was characterized in this paper using the CIELab color space and the whiteness index, with standard illuminant D65 and the standard observer at ten degrees. Based on this information, the color trends used in this type of product in the national market were recognized. In addition, the chemometric techniques of the Principal Component Analysis, Cluster Analysis, and Hierarchical Analysis allowed for recognition of similarities between the observed colors, which found, among other aspects, the greatest visual difference in the pearl white lacquer. On the other hand, the Alaskan white lacquer from Mazda and the universal white lacquer from Nissan were the most similar. It is also concluded that the chromatic and chemometric analyses of spectral data complemented each other; therefore, both are recommended for quality control purposes. Resumo Neste trabalho, caracterizou-se a cor de lacas acrílicas brancas utilizadas para retocar pintura automotriz, através do espaço de cor CIELab e o índice de brancura, utilizando o iluminador padrão D65 e o observador padrão a 10 graus. A partir dessa informação, foi possível reconhecer as tendências da cor usada neste tipo de produtos no mercado nacional. Por outro lado, a aplicação das técnicas quimiométricas de Análise de Componentes Principais, Análise de Grupos e Análise Hierárquica permitiu reconhecer semelhanças entre as cores observadas, encontrando, entre outras, a maior diferença visual na laca de branco perolizado. Por sua vez, a laca do branco Alaska da MAZDA e a do branco universal da NISSAN foram as mais parecidas. Conclui-se, também, que a análise cromática e a quimiométrica de dados espectrais foram complementárias, razão pela qual, em nível de controle de qualidade, ambas são recomendadas.

International audience; The color of white acrylic lacquers utilized to touch up automotive paint was characterized in this paper using the CIELab color space and the whiteness index, with standard illuminant D65 and the standard observer at ten degrees. Based on this information, the color trends used in this type of product in the national market were recognized. In addition, the chemometric techniques of the Principal Component Analysis, Cluster Analysis, and Hierarchical Analysis allowed for recognition of similarities between the observed colors, which found, among other aspects, the greatest visual difference in the pearl white lacquer. On the other hand, the Alaskan white lacquer from Mazda and the universal white lacquer from Nissan were the most similar. It is also concluded that the chromatic and chemometric analyses of spectral data complemented each other; therefore, both are recommended for quality control purposes.; En este trabajo, se caracterizó el color de lacas acrílicas blancas utilizadas para retocar pintura automotriz, mediante el espacio de color CIELab y el índice de blancura, utilizando el iluminante estándar D65 y el observador estándar a diez grados. A partir de tal información, fue posible reconocer las tendencias del color usado en este tipo de productos en el mercado nacional. Por otra parte, la aplicación de las técnicas quimiométricas de Análisis de Componentes Principales, Análisis de Grupos y Análisis Jerárquico, permitió reconocer semejanzas entre los colores observados, encontrando, entre otros, la mayor diferencia visual en la laca de blanco aperlado. Por otro lado, la laca de blanco Alaska de Mazda y la de blanco universal de Nissan fueron las más parecidas. También se concluye que el análisis cromático y el quimiométrico de datos espectrales fueron complementarios, por lo que se recomiendan ambos en el nivel de control de calidad.; Neste trabalho, caracterizou-se a cor de lacas acrílicas brancas utilizadas para retocar pintura automotriz, através do espaço de cor CIELab e o índice de brancura, utilizando o iluminador padrão D65 e o observador padrão a 10 graus. A partir dessa informação, foi possível reconhecer as tendências da cor usada neste tipo de produtos no mercado nacional. Por outro lado, a aplicação das técnicas quimiométricas de Análise de Componentes Principais, Análise de Grupos e Análise Hierárquica permitiu reconhecer semelhanças entre as cores observadas, encontrando, entre outras, a maior diferença visual na laca de branco perolizado. Por sua vez, a laca do branco Alaska da MAZDA e a do branco universal da NISSAN foram as mais parecidas. Conclui-se, também, que a análise cromática e a quimiométrica de dados espectrais foram complementárias, razão pela qual, em nível de controle de qualidade, ambas são recomendadas.

Paint job can be considered as the heart of the automobile manufacturing process from the customer’s point of view. Automobile manufacturing companies spend a hefty amount on the process at times even more than the body itself. Paint process in an automobile is thus a rigorous and time-consuming process involving: pre-treatment, electrodeposition, sealing, priming, coating and then finally inspection. In a typical car manufacturing plant, more than 1000 cars are processed each day. This high quantum and superior quality standards have forced manufacturers to invest and maintain automated modern production line. Sensors and robots are thus employed at each step of the manufacturing process. This review focuses on the sensors used in the paint job, type, and their importance at each step.

Automotive paint sludge (APS) contains valuable material which can be recovered by microwave-assisted pyrolysis as studied by previous researchers. In this study, combined application of microwave absorber and catalyst are studied in order to study the effect of both components in microwave-assisted pyrolysis of APS. Activated carbon and ZSM-5 acted as microwave absorber and catalyst, respectively were used to investigate their effect on pyrolytic oil produced from APS. By using One-Factor-At-Time (OFAT) analysis, results showed that at 1000W power level, 30 minutes radiation time, 6% activated carbon loading and 1.5% catalyst loading, the process was capable to produce highest oil yield of 7.75% pyrolytic oil as compared to other parameters. On the other hand, physical and chemical properties of pyrolytic oil produced via this process was also improved.

Over the past few decades, polymers have progressively replaced metals and metallic alloys in technological applications for which, for example, lightweight, cost-effectiveness, chemical resistance and flexibility for precision-machines components are needed. Furthermore, there is great attention in modifying polymeric surfaces through physical and/or chemical treatments. In this context, the aim of this study is the enhancement of polypropylene specific automotive applications by inducing changes into its surface morphologies. Laser surface texturing technique is of particular interest because of its ability in producing morphological and, consequently, physical and/or chemical modifications on polymer surface. A femtosecond Titanium:Sapphire laser source was employed in order to investigate any variation of surface properties due to the fine tuning of both laser pulse energy and focused laser beam distance from the sample target. The laser treated samples were studied by Scanning Electron Microscopy, μ-Raman spectroscopy and contact angle measurements. The morphological analysis showed that micrometric sized dimple- and groove-like structures were produced after laser irradiation, maintaining mostly unchanged the chemical features of polypropylene surface but changing its wetting properties. These findings have been successfully applied to activate polypropylene surfaces for subsequent painting processes in automotive industry demonstrating that the femtosecond laser surface treatment here studied is an alternative method to the commonly used flame treatments on automotive components improving the paint adhesion to the treated polypropylene surfaces.

Various studies on differentiation of the automotive paints have been published in support of the evidential value of automotive paint comparisons [1] , [2] , [3] , [4] , [5] , and were based on the automotive populations in the regions outside of Singapore. However, the frequency information of the automotive paint characteristics in the previous studies may not be directly relevant to the situation in Singapore. To obtain the local frequency information of the automotive paint characteristics, a population study based on the automotive distribution in Singapore was necessary to apprehend the variations in the distribution of vehicle makes and colours, the visual and microscopical features, and the chemical compositions of the paint samples. This was facilitated with the data obtained from the local transport authority, the surveys conducted on random vehicle samples on the road, and the analysis of the existing collection of automotive paint samples taken from the laboratory’s vehicle paint database that closely resembles the vehicle population of Singapore. A discrimination study involving comparative analysis of 256 automotive paint samples from six colour groups was performed to evaluate the discriminating power of the laboratory's standard paint examination protocol: visual and microscopical examinations, Fourier Transform Infrared (FT-IR) Spectroscopy and Scanning Electron Microscopy with Energy Dispersive X-ray (SEM/EDX) Spectroscopy. Visual and microscopical comparisons of the physical characteristics in these paint samples yielded 54 indistinguishable pairs. When further subjected to FT-IR analysis, 51 pairs were distinguished in terms of their chemical compositions. The elemental compositions of the remaining three indistinguishable pairs were compared using SEM/EDX, and one pair remained indistinguishable. A combination of these analytical techniques yielded a discriminating power (DP) of 0.99981. The DP in this study is in support of the DP values reported in the published studies [1] , [2] , [3] , [4] , [5] .

Conversion of waste to wealth has been one of the ways to reduce the volume of industrial waste to disposal site, hence reducing the impact to the environment. In this work, paint sludge from an automotive industry (APS) was converted into activated carbon through chemical activation (potassium hydroxide (KOH)) using microwave pyrolysis technique. The effect of power and radiation time on the produced activated carbon were investigated and characterised (carbon content, surface area, and pore volume) to identify the possibility of application as a supercapacitor. Potassium hydroxide activation of the APS char via microwave pyrolysis has shown that power level and radiation time has influenced the yield of the APS activated carbon. A longer radiation time and higher power supply has produced activated carbon having higher carbon contents, lower impurities, higher surface area and higher pore volume. Thus, the APS activated carbon obtained via microwave pyrolysis at power supply 1000 W and 45 minutes radiation time had produced the highest surface area and total pore volume of 434.3 m2/g and 0.2901 cm3/g, respectively. However, the produced activated carbon is not suitable for the supercapacitor application as the minimum surface area requirement must be more than 1000 m2/g. The pore size of the activated APS char produced in this study was in the range of mesopores size which was also considered very poor for supercapacitor application. The outcome of this research has shown that the produced activated carbon could otherwise be used for other application than a supercapacitor.

The driver's criminal conduct of evading after a collision (hit-and-run) is a problem for law enforcement agencies worldwide. Witness reports or video images are not always reliable nor available. Fragments of paint left behind at the crime scene become essential for the criminal investigation process. This study reviewed publications about automotive paint analysis, published from 2010 to 2019. In each study, we evaluated: technique, paint layer, data analysis methodology, model validation, chemical characterization, samples degradation and origin (both their sources and their support bases - plastic vs. metallic). Of the techniques reviewed, infrared spectroscopy was the most commonly used technique for forensic paint analysis. The authors reported complementary or alternative techniques that have been used to analyze paint samples, such as optical examination, Raman spectroscopy and elemental analysis and even more rare or innovative techniques i.e. optical coherence tomography. We also detailed the various chemometric techniques that have been employed when analyzing the resulting spectra. In summary, the information collated in this study will provide researchers that intend to create automotive paint databases for forensic purposes, with a suite of instrumental techniques, analytical methodologies and data interpretation protocols that can be incorporated into a database.

Multilayered automotive paint fragments, which are one of the most complex materials encountered in the forensic science laboratory, provide crucial links in criminal investigations and prosecutions. To determine the origin of these paint fragments, forensic automotive paint examiners have turned to the paint data query (PDQ) database, which allows the forensic examiner to compare the layer sequence and color, texture, and composition of the sample to paint systems of the original equipment manufacturer (OEM). However, modern automotive paints have a thin color coat and this layer on a microscopic fragment is often too thin to obtain accurate chemical and topcoat color information. A search engine has been developed for the infrared (IR) spectral libraries of the PDQ database in an effort to improve discrimination capability and permit quantification of discrimination power for OEM automotive paint comparisons. The similarity of IR spectra of the corresponding layers of various records for original finishes in the PDQ database often results in poor discrimination using commercial library search algorithms. A pattern recognition approach employing pre-filters and a cross-correlation library search algorithm that performs both a forward and backward search has been used to significantly improve the discrimination of IR spectra in the PDQ database and thus improve the accuracy of the search. This improvement permits inter-comparison of OEM automotive paint layer systems using the IR spectra alone. Such information can serve to quantify the discrimination power of the original automotive paint encountered in casework and further efforts to succinctly communicate trace evidence to the courts.

A prototype library search engine has been further developed to search the infrared spectral libraries of the paint data query database to identify the line and model of a vehicle from the clear coat, surfacer-primer, and e-coat layers of an intact paint chip. For this study, search prefilters were developed from 1181 automotive paint systems spanning 3 manufacturers: General Motors, Chrysler, and Ford. The best match between each unknown and the spectra in the hit list generated by the search prefilters was identified using a cross-correlation library search algorithm that performed both a forward and backward search. In the forward search, spectra were divided into intervals and further subdivided into windows (which corresponds to the time lag for the comparison) within those intervals. The top five hits identified in each search window were compiled; a histogram was computed that summarized the frequency of occurrence for each library sample, with the IR spectra most similar to the unknown flagged. The backward search computed the frequency and occurrence of each line and model without regard to the identity of the individual spectra. Only those lines and models with a frequency of occurrence greater than or equal to 20% were included in the final hit list. If there was agreement between the forward and backward search results, the specific line and model common to both hit lists was always the correct assignment. Samples assigned to the same line and model by both searches are always well represented in the library and correlate well on an individual basis to specific library samples. For these samples, one can have confidence in the accuracy of the match. This was not the case for the results obtained using commercial library search algorithms, as the hit quality index scores for the top twenty hits were always greater than 99%.

This paper discusses that three-dimensional (3D) warp knitted spacer structures offer significant attributes that create sustainable production advantages in dry exhaust systems for the automotive paint industry. The advantages that are offered include improved airflow and the potential to combine to a composite solution with a high paint holding capacity; this concept of filtration also offers the possibility of a durable filter capable of industrial cleaning and reuse numerous times. The paper describes the innovation of these 3D warp knitted spacer filters from theoretical and traditional filtration aspects, followed by an empirical characterization that justifies commercial trials within the industry.

The clear coats from a collection of automotive paint samples of 139 vehicles, covering a range of Australian and international vehicle manufacturers and sold in Western Australia, were characterised using FT-Raman spectroscopy. Principal component analysis (PCA) revealed 19 distinct classes that were associated with the vehicles' manufacturer and model, and in the case of Australian manufacturers, the years of manufacture. Linear discriminant analysis based on the PCA groupings gave excellent discrimination between the groups with 96.9% of the calibration set and 97.6% of the validation set being correctly classified. Although the sample set comprised only vehicles available in Australia, the methodology used is universal and hence applicable in any jurisdiction that is willing and able to generate a statistically significant data set and maintain and update it as new vehicles appear on the market. A FT-Raman spectroscopy-based database would rapidly provide information regarding vehicle origin and manufacture and hence generate investigative leads for questioned paint samples found at incident sites. Copyright © 2016 John Wiley & Sons, Ltd.

The aim of this review is to summarize the forensic science and analytical chemistry literature related to the comparison of infrared spectra. Most of the peer-reviewed papers referenced in this review have been published during the past ten years. This review is divided into two major (although not all-inclusive) sections: library searching (comparing one spectrum or group of spectra representing a sample to a spectral database) and what has been called “pattern recognition” (differentiating one set of spectra from another set by identifying the spectral features that provide the necessary discrimination). In the absence of discriminating features, spectra may be determined to not be “significantly different” and, in the forensic context, the possibility of the spectra originating from the same source (e.g., assembly plant in the case of an automotive paint sample) cannot be discarded. Library searching algorithms report a “quality index” or “similarity score,” whereas pattern recognition techniques attempt to collect information from a training set in the form of a response function that can be applied independently to other spectra for the purpose of classification, discrimination or even association. Additional tools are also discussed within this review including the use of a likelihood ratio to estimate the strength of similarity between one spectrum and another. In forensic applications, library search algorithms and pattern recognition techniques can only provide class evidence and cannot individualize the sample, e.g., in the case of an automotive paint search, they cannot identify the specific vehicle, only the “make” and model of the vehicle.

This paper focuses on the research and development of a new paint shop concept for the automotive industry, based on Industry 4.0 and Digital Factory ideas. The Paint Shop 4.0 project has been carried out on behalf of a German car manufacturer, in cooperation with ProPoint Sp. z o.o. Sp. k. and industrial partners. The main goal of this research is to reduce the primary bottleneck in the operation of a paint shop, which is caused by frequent changeovers of painting guns. A new type of sequencing problem is studied from both an algorithmic and a practical point of view. The original ‘Car Sequencing Problem’ focuses on determining the sequence before production starts, without the possibility of later change to this sequence. The new problem consists of real-time car sequencing using a buffer for the purpose of considering dynamic changes. Work begins with identifying and analyzing the causes of the emerging problem. Then, using tools like Virtual Engineering and Virtual Commissioning, the following tasks are performed: modeling of an existing production line with a buffer, model validation, and the development of methods to improve the sequencing process. Two heuristics based on a set of simple rules and one more advanced heuristic are proposed. Their effectiveness has been tested during simulations, based on real data, and compared with current industry solutions. The extensive computational experiments show that heuristics-based proposal outperforms the methods known from the literature in terms of in terms of matching to industry requirements. This indicates that it is possible to improve the sequencing effectiveness, and as a result a smart buffer control system is proposed. Validating the proposed solution in a virtual environment paves the way to implement the Paint Shop 4.0 concept in a real plant in the future.

Due to the excellent mechanical properties fiber-reinforced plastics (FRP) are increasingly being used in technical lightweight products in order to achieve a multimaterial design. Due to different melting temperatures, the use of conventional thermal joining technologies is restricted, and the demand of efficient mechanical and adhesive joining technologies is increasing. Within the scope of this publication, the damage behavior of self-piercing riveted hybrid joints using carbon fiber reinforced plastics and metals is analyzed and evaluated in detail regarding the requirements of the automotive industry. Subsequently, hybrid joints are subjected to a thermal profile, which is modelled on the cathodic dip coating drying process in the automotive paint shop. It is shown that the oven process induces damage in the CFRP to self-piercing full riveted joints, which is shown in the form of fiber breaks as well as inter-fiber breaks and delamination. Also, with regard to these effects, geometric optimizations of the self-piercing rivet are carried out, which prevent damages occurring during the oven process. A combination of both optimizations, resulting from the joining and the oven process, leads to a material- and requirement-compliant joining technology, which enables the low-damage joining of CFRP with metals along the automotive process chain.

This population study was conducted to assess the frequency of physical, microscopical, and chemical properties of automotive paint chips. Population studies of trace evidence provide valuable analytical data for criminalists to assess evidentiary significance. Two-hundred automotive paint chips were collected from auto body shops from the Northeastern United States. All samples were analyzed using stereomicroscopy, brightfield, and polarized light microscopy. Red paints were targeted for further analysis using a sequence of modern instrumental techniques commonly used by forensic paint examiners: Fourier-transform infrared (FT-IR), Raman, and ultraviolet-visible (UV-Vis) microspectroscopy. The discrimination potential of each analytical method was evaluated by inter-comparing the paint samples. Results demonstrated that macroscopic and microscopic properties were able to differentiate 99.995% of the population (one undifferentiated pair out of 19,900). When combined with either FT-IR or UV-Vis microspectroscopy, all paints were differentiated. The results of this research lead to the conclusion that one would not expect to encounter two indistinguishable paint chips originating from different sources during the investigation of a single event.

The paper focuses on presentation of innovative paint shop concept for automotive industry, based on Industry 4.0 idea. Work begins with introduction of Virtual Engineering and Virtual Commissioning methods. Using virtual environments to test and verify new solutions allows to check them efficiency before implementing these ideas in the real plant. The main goal of the research is to improve paint shop efficiency and productivity. The simulation station, used for the purpose of research, is presented from hardware and software point of view. For the considered case study new selected heuristics, based on modification of existing ones, are proposed. The obtained results are compared and presented in the paper.

Although ubiquitous on accident scenes, the polymers from headlight optics are often neglected in hit-and-run cases, and their evidential value restrained to direct comparison once a corresponding vehicle is found. Multilayered automotive paint fragments are preferred for their access to corresponding databases (PDQ, EUCAP) to infer models and brands of cars. The potential of polymers headlights for providing forensic intelligence has never been exploited, principally due to the lack of diversity, of appropriate databases, and of case examples. The motives are very simple however. Headlight polymers suffer from a lack of differentiation, and about 90% of them are composed of polymethylmethacrylate (PMMA). The discriminating powers using techniques in sequence typically range from 30 to 60%. In this paper, we take advantage of the extreme sensitivity of Surface Enhanced Raman Spectroscopy (SERS) to analyze the dye composition of the polymer headlights. The measurements by standard Raman spectroscopy at 488, 633, and 785nm permits us to identify the polymer type with relative ease. 51 out of 53 samples are composed of PMMA, the two remaining being either Polycarbonate or Polybutylene terephthalate. Additionally, using SERS with silver colloids at 488 and 633nm, provides enhanced spectra of the dyes used in the composition with an extreme sensitivity and specificity. With SERS we are able to differentiate the majority of the headlights with a remarkable 90-100% discriminating power. Solvent Orange 60, Solvent Red 52 and Solvent Red 111 were successfully identified as dyes used in the manufacture of the headlights. These results demonstrate that a combined Raman-SERS approach has the potential to replace an otherwise lengthy sequence of many different analytical techniques. With one single instrument, we offer the possibility to combine an analysis of the polymer type, and of the dye components with high discriminating capabilities. These results open up new opportunities for exploiting headlight plastics in road accidents investigations. It has the potential to help in source attribution, and/or database building in a forensic intelligence perspective.

The aging response of two Al-3Mg alloys with Cu addition 1 wt% has been tracked under simulated automotive paint bake conditions ( ∼ 20 min, 160 and 200 °C) to quantify the processes controlling hardening. The decomposition of the solid solution, observed by atom probe tomography, has been interpreted using a novel pair correlation function approach and incorporated into a model for prediction of precipitation hardening. It is shown that the hardening is controlled by clusters/Guinier-Preston-Bagaryatsky (GPB) zones similarly to what has been previously observed in much higher Cu containing 2XXX-series alloys. Interestingly, it is shown that very small additions of Cu ( 0.1 at%) can be used to catalyze a high number density of strengthening particles owing to the high enrichment in Mg compared to particles found in more conventional high Cu/low Mg alloys. This allows hardening during the first hour of aging that is as high as that obtainable in these high Cu alloys.

Millions of cars are sold around the world and tons of paint are used for these cars. Since the car paint industry is alive in this way, new developments in the paint sector have been taking place every day. It is important to determine how these developments affect paint erosion. Solid particle erosion wear is a subject that keeps its update for car paints and it always needs to be investigated in detail. The target of this experimental study is to investigate solid particle erosion behavior of a commercial acrylic/melamine primer surface and basecoat of automotive paint. As a erodent, silica particles having a weight of 1 to 5 kg were used. Tests were performed at 30° and 90° impact angle and particle velocity 23 m s−1. With this work, an idea about the adhesion of the car paint coatings to the material surface was obtained.Millions of cars are sold around the world and tons of paint are used for these cars. Since the car paint industry is alive in this way, new developments in the paint sector have been taking place every day. It is important to determine how these developments affect paint erosion. Solid particle erosion wear is a subject that keeps its update for car paints and it always needs to be investigated in detail. The target of this experimental study is to investigate solid particle erosion behavior of a commercial acrylic/melamine primer surface and basecoat of automotive paint. As a erodent, silica particles having a weight of 1 to 5 kg were used. Tests were performed at 30° and 90° impact angle and particle velocity 23 m s−1. With this work, an idea about the adhesion of the car paint coatings to the material surface was obtained.