Paint Layers Research Articles

Quality Control Analysis of Painting Results in Steel Construction Projects Using Statistical Quality Control Methods and Failure Mode Effect Analysis at PT. BSB

PT BSB is a company engaged in construction specialising in steel fabrication. There are various projects carried out at the company, namely bridges, steel structures, buildings, towers, and others. The research was conducted to analyse the quality of results in the painting process at PT BSB using statistical quality control (SQC) and failure mode effect analysis (FMEA) methods. Data collection is done by collecting primary and secondary data used in this study. The four types of painting defects obtained from the research results are Sagging/Runs, Orange Peel, Pin Hole and Seeds/Dirt. Based on the FMEA method, the level of defects can be determined based on the cumulative percentage value produced, where the highest defect value is 1750 Sagging/Runs defects. One of the factors causing the defect is the uneven spraying of paint, causing a layer of paint that is too thick, resulting in excessive accumulation of paint in certain parts that flow vertically and unevenly. From this research, it can be concluded that the company must use the SQC method to determine the causes of defects in the painting process and analyse improvements that must be prioritised. Keywords: Failure Mode Effect Analysis (FMEA), Painting Process Analysis, Statistical Quality Control (SQC)

Optical and terahertz methods for studying easel oil paintings

Subject of study. This study focuses on the application of terahertz tomography methods to easel oil paintings. Aim of study. The aim of this study is to assess the effectiveness of terahertz tomography in analyzing the layered structure of artworks and detecting hidden damage, elements, and annotations. Method. The study employed traditional analysis methods, such as infrared, ultraviolet fluorescence, and X-ray imaging. Special emphasis was placed on terahertz tomography, which enables non-invasive imaging of internal structures. Main results. The study showed that terahertz tomography allows for the differentiation of materials used in oil paintings. This method enables a detailed examination of the layered structure without damaging the object under investigation, revealing elements that cannot be detected using other methods. The novelty of this study lies in the proposed application of terahertz tomography for preliminary in situ examination of paintings to detect hidden defects and possible inscriptions on the reverse side of artworks. Practical significance. The results obtained from this study are valuable for researching, assessing the preservation status of, and restoring oil paintings. Specifically, the proposed method is suitable for detecting defects and hidden elements beneath paint layers without damaging the colorful surface. The terahertz tomography method proves particularly effective when applied in situ, as it does not require paintings to be dismantled.

Enhancement of low-zinc phosphate coatings with addition Ni2+ and Mn2+ cations: Structure, corrosion resistance and paint adhesion

Multi-cation phosphate coatings are used in various industries today to enhance the properties of the painting process. This study explored the impact of adding nickel and manganese ions to the low-zinc phosphating process on the properties of the resulting coating. The first step of the research examined the influence of the bath phosphating agents’ concentration, temperature and immersion time and pH on the phosphate coating on the steel 41Cr4 substrate. The second step explored the impact of varying concentrations of Zn, Ni and Mn cations in the phosphating bath and the third step compared the characteristics of zinc (single-cation), Zn–Ni (two-cation) and Zn–Ni–Mn (three-cation) phosphate. The surface thickness and weight per unit area of the phosphate coating, the total and free acid values, and the coating morphology and microstructure were measured; corrosion resistance tests including alkali solubility and salt spray tests were conducted. In addition, scratch, impact, hardness and bending tests of the paint layer were performed. The results indicated that introducing Ni2+ and Mn2+ cations into the low-zinc phosphating bath enhances the structure, corrosion resistance and paint adhesion of the phosphate coating. Scanning electron microscope images revealed that the optimal three-cation coating has a cubic and sheeted structure. Atomic force microscope analysis also demonstrated that in the tri-cation phosphate coating, compared to the zinc phosphate coating, the roughness (Ra) decreases by up to 50% and reaches 8.92 nm. The optimal three-cation coating has the highest corrosion resistance, which is attributed to the higher uniformity, lower porosity, fine crystalline structure, and high percentage of corrosion-resistant phases in the coating composition. The time to the onset of initial corrosion signs in the salt spray test, both without and with paint, increases by 50% and 225%, respectively, resulting in 11 and 180 h.

Microanalytical investigation of brazilian coat of arms paintings on paper

Heraldry in Latin American art of the twentieth century can be considered rare. In this context, the material composition of coat of arms paintings on paper attributed to the Brazilian painter José Wasth Rodrigues is investigated for the first time using a microanalytical approach. Microsamples from 5 municipal coats of arms dated 1932 were analysed using Raman microscopy, Attenuated Total Reflection Fourier Transform Infrared spectroscopy (ATR-FTIR), and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS). SEM-EDS results revealed the artist's choice of using metallic aluminium and brass in the representation of silver and gold colours, respectively. Raman microscopy analyses showed the use of traditional inorganic pigments, such as ultramarine blue, indigo, Prussian blue, yellow chromates and vermillion. In contrast, the results showed that the painting with an unusual signature attributed to the artist (W. instead of J.W.R, commonly found) contains synthetic organic dyes Orange 5, Red 53, and Yellow 1 (introduced in the 1900s). This discovery raised hypothesis of questioning authorship for this particular painting. ATR-FTIR analysis of a paint fragment from one painting confirmed the use of gum arabic as a binder. ATR-FTIR analyses of efflorescences collected from a blue paint layer of a particular coat of arms suggest protein and lipid content, raising suspicion of either the use of the tempera technique in this particular paint or remains of a past microorganism activity. Robust information was obtained on the chemical characterization of the coat of arms, enhancing comprehension of the painting techniques employed by the artist and providing insight into the production of heraldic art in Brazil at the beginning of the 20th-century.

Optimization Design of DC Electromagnet Coil Considering the Power Consumption and Cost

Electromagnet coil is mainly composed of enameled wire which wound on the coil skeleton, and the function is to convert the electrical signal into a magnetic signal, which is a very important electric‐magnetic conversion element. When designing the electromagnet coil, usually only the total winding turns and winding inner diameter can be calculated, and the specific design parameters such as the diameter of copper wire, paint layer thickness, and winding turns of each layer can only be selected through experience, indicating that the design method should be improved. In addition, the unreasonable design parameters will seriously affect the power consumption and cost of coil, so it is highly necessary to improve the optimization design method. In order to solve the above problems, an optimization design method for DC electromagnet coil is proposed in this paper. This method simultaneously takes into account both power consumption and manufacturing cost, and can achieve the optimal matching of design parameters. In this paper, the structure of electromagnet coil is introduced, and the theoretical calculation model of resistance is improved first. Then, according to the expected requirements of electromagnet coil for steady current, the optimization design method is proposed and the optimal design parameters are obtained. Finally, the effectiveness of the proposed optimization design method is verified by the test platform of electromagnet coil. The results show that the electromagnet coil designed by the optimization design method fully meets the expected requirements. The relevant research results can provide reference for the optimization design of electromagnet coil, which has a certain engineering practical value. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

Tuning Local Order in Starch Nanoparticles Exploiting Nonsolvency with "Green" Solvents.

Starch is a renewable biopolymer that can be sourced from agricultural waste and used to produce nanoparticles (SNPs). In particular, amorphous SNPs have potential application in numerous fields, including the consolidation of weakened paintings in the cultural heritage preservation. Starch dissolution followed by nanoprecipitation in nonsolvents is an advantageous synthetic route, but new methodologies are needed to feasibly control the physicochemical properties of the SNPs. Here, we explored nanoprecipitation by nonsolvency using a set of "green" solvents to obtain amorphous SNPs, rather than starch nanocrystals already reported in the literature. The effect of the nonsolvent on the ordering of polymer chains in the obtained SNPs was studied. The recovery of local order (e.g., isolated V-type helices) after dissolution was shown to depend on the type of solvents used in the dissolution and precipitation steps, while long-range order (extended arrays of helices) is lost. Aqueous dispersions of the SNPs provided effective consolidation of powdery painted layers, showing that the selection of particle synthetic routes can be dictated by sustainability and scalability criteria. These "green" formulations are candidates as new consolidants in art preservation, and the possibility of tuning local order in amorphous starch assemblies might also impact fields like food chemistry, pharmaceutics, and nanocomposites, where SNPs with tunable amorphousness are more advantageous than nanocrystals.

Evaluation of commonly used reinforcement materials for color paintings on ancient wooden architecture in China

Over recent decades, various heritage institutions have utilized a multitude of materials to reinforce the painted layers of ancient Chinese wooden architecture. In this study, we conducted a comprehensive evaluation of the properties and durability of four widely used reinforcement agents, i.e., AC33, B72, FKM, and FEVE, using a series of techniques, including contact angle tests, water vapor permeability measurements, color difference evaluations, tensile strength tests, UV–vis spectrometry, and scanning electron microscopy (SEM). The results demonstrate that the transmittance rates of the films made from these four reinforcement agents are approximately 100% in the visible light range. Among them, the B72 film exhibits the highest hydrophobicity. The AC33 film has better permeability, fair tensile strength, and is more hydrophilic. FKM film is more hydrophobic but has lower permeability and tensile strength. Overall, the FEVE film presents the best comprehensive properties, including better hydrophobicity, higher permeability, and tensile strength. This research provides data evidence to guide heritage conservators and curators in decision-making when selecting appropriate reinforcement materials in practice.

Comparative study of infrared nanosecond laser surface paint removal for carbon fiber reinforced polymer and glass fiber reinforced polymer

Carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) are widely used in aerospace applications due to their excellent properties. Green and efficient laser cleaning technology has a broad development prospect in the paint removal treatment of aerospace composites. However, the lack of theoretical analysis and guidance has prevented the industrial application of laser paint removal technology. An infrared nanosecond laser is used to clean the paint layer on the surface of CFRP and GFRP, and the best paint removal process parameters are explored. Surface micromorphology and 3D morphology of CFRP and GFRP after cleaning are observed to reveal the cleaning quality. The FTIR spectrum is used to verify the cleanliness of the paint layer. In addition, the contact angle and bonding force are tested, and the experimental results show that the surface wettability of both surfaces is enhanced after cleaning, and the paint adhesion of both surfaces is improved after repainting. Temperature monitoring, acoustic signal monitoring and high-speed photography monitoring are used to monitor the two cleaning processes respectively. The temperature, amplitude intensity, and plasma size of the two in the cleaning process are compared and analyzed. Based on the monitoring results, it is found that the cleaning mechanism of fiber-reinforced composites includes thermal ablation, vibration effect and plasma impact effect.

Non-destructive experimental technique to determine ball contact load in rolling machine elements

Rolling machine elements, such as ball bearings, ball screws, or guiding systems are commonly used in diverse industrial applications. These components typically assume uniform load distribution among the balls or rely on analytical expressions. However, experimental load distribution measurement remains a challenge. This research work proposes a non-destructive experimental technique designed to determine ball contact load. The method uses painted surfaces to visualize the contact area under each rolling element, combined with an analytical formulation that modifies Hertz’s original contact equations to account for the influence of the painted layer thickness. Analytical results are compared with experimental tests on flat and curved surfaces. The results show a good agreement between the proposed painted surface formulation and measured contact areas.

Velocities of transmission eigenchannels and diffusion

The diffusion model is used to calculate both the time-averaged flow of particles in stochastic media and the propagation of waves averaged over ensembles of disordered static configurations. For classical waves exciting static disordered samples, such as a layer of paint or a tissue sample, the flux transmitted through the sample may be dramatically enhanced or suppressed relative to predictions of diffusion theory when the sample is excited by a waveform corresponding to a transmission eigenchannel. Even so, it is widely assumed that the velocity of waves is irretrievably randomized in scattering media. Here we demonstrate in microwave measurements and numerical simulations that the statistics of velocity of different transmission eigenchannels are distinct and remains so on all length scales and are identical on the incident and output surfaces. The interplay between eigenchannel velocities and transmission eigenvalues determines the energy density within the medium, the diffusion coefficient, and the dynamics of propagation. The diffusion coefficient and all scattering parameters, including the scattering mean free path, oscillate with the width of the sample as the number and shape of the propagating channels in the medium change.

CONSERVATION OF A PAINTED WOODEN COFFIN AT DAHSHUR ARCHAEOLOGICAL AREA

This paper aims to document the conservation processes of a polychrome wooden coffin in the Dahshur archaeological area dating back to the late period. The exterior part of the coffin is decorated with a painted layer. Visual observation, 2D Program, and Optical Microscopy (OM) were used. wood identification. The coffin was in a bad condition. It was covered with a thick layer of dust, losing parts of the painted and gesso layers, as well as other parts of these layers, were lost. Some parts were missing from the head area of the lid coffin. The conservation processes of the wooden coffin included mechanical and chemical cleaning, reattachment of the separated parts of the ground layer and painted layers, filling the edge of the painted layer, and consolidating the painted layer. The conservation process included mechanical cleaning using soft brushes, chemical cleaning using ethyl alcohol and distilled water for painting, stabilization of the separated gesso layer using Paraloid B72, filling cracks of the gesso layers using glass microballoon with Paraloid B72 and consolidating the painted layer with calcium oxide nanoparticles with Klucel G (hydroxypropyl cellulose) 0. 5%

Development of craquelure patterns in paintings on panels

Panel paintings are multi-layer structures composed of humidity-sensitive materials. Preventing or limiting stresses in these structures, generated by the loss or gain of moisture, requires an understanding of the relevant processes and risks. A three-dimensional elastic model of a panel painting was used to analyse surface stresses and understand how crack patterns are developed in the two-layer structure of the pictorial layer—the gesso and the paints. Two historically important paint types were considered—egg tempera and oil paints, laid on a gesso produced following historical procedures. Two scenarios of stress development were analysed: permanent cumulative drying shrinkage of paints or gesso, owing to gradual loss of water or evolution of the molecular composition of the binders, and moisture-induced cyclic swelling of the wood substrate. Ratios of distances between cracks in the tangential and longitudinal directions of a wood panel to the layer thickness were estimated for increasing magnitudes of materials’ dimensional change in the two scenarios. The critical values of the ratios for which stress in the midpoint between the cracks dropped below the value inducing strain at break in the materials and saturation of the crack patterns occurred, was approximately 3–4 or 5–6 for the paints and the gesso, respectively. The critical distance normalized to the gesso thickness between cracks parallel to the wood grain induced by cyclic swelling of the wood substrate due to relative humidity variation in the range of 50–70% was 6. The study demonstrated that crack spacings in the fully developed crack systems remain sensitive only to the thicknesses of paint or gesso layers which, therefore, can be derived from the crack pattern geometry. Existing flaws in gesso were found not to increase the risk of new crack development.

Influence of Organic Coating Thickness on Electrochemical Impedance Spectroscopy Response

Electrochemical Impedance Spectroscopy (EIS) is a non-destructive and powerful technique for characterizing corrosion systems, allowing for the evaluation of surface reaction mechanisms, mass transport, kinetic evolution, and corrosion levels of materials. This study aims to analyze the progression of corrosion using EIS, with a focus on the influence of organic coating thickness. For this purpose, layers of high-purity epoxy paint were applied to carbon steel plates with thicknesses of 50 µm, 80 µm, and 100 µm. During the research, a direct correlation was observed between coating thickness and corrosion resistance, emphasizing the importance of identifying the optimal thickness for each type of coating. Additionally, it was found that thicker coatings may experience electrode penetration due to the tensions generated during deposition, resulting in cracks between the layers, while thinner coatings allow electrolyte penetration as they do not provide adequate protection to the base steel. Therefore, the 80 µm thickness demonstrated greater resistance to corrosion compared to the other tested thicknesses.

A Novel LIBS Sensor for Sample Examinations on a Crime Scene.

In this work, we present a compact LIBS sensor developed for characterization of samples on a crime scene following requirements of law enforcement agencies involved in the project. The sensor operates both in a tabletop mode, for aside measurements of swabbed materials or taken fragments, and in handheld mode where the sensor head is pointed directly on targets at the scene. The sensor head is connected via an umbilical to an instrument box that could be battery-powered and contains also a color camera for sample visualization, illumination LEDs, and pointing system for placing the target in focus. Here we describe the sensor's architecture and functionalities, the optimization of the acquisition parameters, and the results of some LIBS measurements. On nano-plotted traces at silica wafer and in optimized conditions, for most of the elements the detection limits, in term of the absolute element masses, were found to be below 10 picograms. We also show results obtained on some representative materials, like fingerprints, swabbed soil and gunshot residue, varnishes on metal, and coated plastics. The last, solid samples were used to evaluate the depth profiling capabilities of the instrument, where the recognition of all four car paint layers was achieved.

Enhanced Biocidal Activity of Heterophase Zinc Oxide/Silver Nanoparticles Contained within Painted Surfaces

Today, one of the biggest challenges is infections in the painted walls of hospitals. Acrylic-based paints are a target of antibiotic-resistant microorganisms since they contain cellulosic compounds as thickeners. The aim of this study was to synthesize and investigate the biocidal activity and toxicity of heterophase ZnO-Ag nanoparticles fixed in water-based acrylic paint layers in reference to a nontreated water-based paint. The ZnO-Ag nanoparticles with average particle sizes of about 80 nm were simply obtained by electrical explosion of two twisted wires in an oxygen-containing atmosphere. The nanoparticles and modified paint were characterized using SEM, TEM, XPS, and XRD techniques. The antimicrobial activity of the nanoparticles and modified paint layers was tested against P. aeruginosa, S. aureus, MRSA, E. coli bacteria, and C. albicans using ISO 22196. The antiviral activity against smallpox virus was tested according to ISO 21702. Flow cytometry tests were used to investigate the toxicity of the modified paint coating. As-synthesized nanoparticles had “Janus-like” morphology, with a clear interface inside the nanoparticle. Nanoparticles had enhanced antibacterial activity, which is based on the nanoparticle photocatalytic activity in water decomposition and reactive oxygen species generation. The paint coating with a ZnO-Ag nanoparticle mass ratio of 1.0 wt.% displayed significant antibacterial activity (more than a 99% reduction) and 100% antifungal activity. In addition, this coating inactivates >99% of the virus after 2 h of contact relative to a nontreated control paint. The paint coating showed low toxicity against the sensitive 3T3 fibroblast cell line. More than 90% cell viability was observed after 24 h of incubation with the sample extract. Therefore, heterophase ZnO-Ag nanoparticles have high biocidal activity and low toxicity use and can be applied to other commercial water-based paints to improve their performance against pathogens.

Effect of High-Power Laser Cleaning for Surface Contaminants Removal on SS304L

In this study, artificially formed corrosion and paint layers on 304L stainless steel (SS304L) specimen were removed using a kilowatt level high-power Nd:YAG laser. A laser power of 1140 W and a pulse duration of 89 ns were used for the corrosion removal, and a laser power of 850 W and a pulse duration of 54 ns were adopted for the paint removal. Surface composition was analyzed via electron probe micro-analysis (EPMA) and x-ray diffraction (XRD) analysis before and after the laser cleaning process, confirming that the corrosion and paint layers were successfully removed from the SS304L surface by the laser cleaning process. The effect of the laser cleaning process on the mechanical properties of SS304L was investigated. The hardness and tensile strength of the laser-cleaned specimens were analyzed to determine their mechanical properties. After the laser cleaning process, the surface hardness was slightly increased up to depths of 250 µm for the corrosion removal and up to 50 µm for the paint removal. However, only marginal changes in tensile strength and elongation were detected after the laser cleaning process. These results confirmed that laser cleaning can effectively remove surface contaminants (i.e., corrosion and paint) on SS304L with only a minimum modification of microstructure and mechanical properties.

Effect of Surface Condition on the Results of Chemical Composition Measurements of Scrap Copper Alloys

The processing of copper-bearing scrap makes it possible to reduce the costs and energy consumption of obtaining copper alloy products compared to producing them from primary raw materials. To achieve this, it is necessary to quickly and accurately determine the content of alloying elements in individual scrap elements. However, the copper-bearing scrap obtained at secondary raw materials collection points consists of elements with various surface conditions (due to contamination, shape, paint coatings, roughness, etc.). The paper contains research results on the influence of surface roughness and paint coatings on the measurement result of the content of alloying elements in copper-bearing scrap. Three mobile spectrometers were used for measurements: spark-induced optical emission spectroscopy (OES), X-ray fluorescence spectrometry (XRF) and laser-induced breakdown spectroscopy (LIBS). The tests used elements with different surface roughness (from Ra = 0.03 μm to 6.7 μm) and covered with various types of varnish (alkyd, water-based, oil-phthalic, acrylic, oil-alkyd). It was found that the roughness of Ra < 2 μm does not significantly affect the results of the measurements with the OES and LIBS spectrometers, and a larger scatter of measurement results was observed for the XRF spectrometer compared to OES and LIBS. For Ra > 2 μm, a significant impact of roughness was found on the measurement results (this may result in the erroneous classification of the scrap as an incorrect material group). The influence of paint coatings on the measurement is much stronger compared to surface roughness. Even a single layer of paint can cause a change in the measurement result of the content of alloying elements by more than 10%. In the case of an OES spectrometer, paint coatings may prevent the measurement from being performed (which means that no measurement result can be acquired).

Numerical Simulation and Experimental Study of Nanosecond Pulsed Laser Cleaning of Aluminum Alloy Surface Paint Layer

Numerical Simulation and Experimental Study of Nanosecond Pulsed Laser Cleaning of Aluminum Alloy Surface Paint Layer

The Effect of Air Pressure and Nozzle Distance on the Quality of Water-Based Painting Using a Gravity-Feed Spray Gun

Environmental influences can cause corrosion or damage to materials, which is why paint coating is used to protect them. Some of the factors that affect the quality of the paint are technical, such as setting the air pressure and spray gun nozzle spacing. The experimental research aims to determine how air pressures of 1.5, 2, and 2.5 bar and nozzle spacings of 10–15–20 cm affect the gloss and thickness of the water-based paint layer. A gravity-feed spray gun was used for this purpose. The luster test method uses an AMTAST AMN60 glossmeter with the ASTM D523-08 standard, and the thickness test uses a coating thickness gauge with the ASTM E 376-96 standard. The air pressure and the distance of the spray gun nozzle affect the gloss and thickness of the paint layer. Parameter 2 bar/15 cm yielded the highest gloss of 92.77 GU, while parameter 2.5 bar/10 cm resulted in the highest coating thickness of 0.26 mm.

Zinc white marker paint in Mondrian’s neoplastic paintings

This research provides new insights into the composition of zinc white paints used by Piet Mondrian during his neoplastic period. Nine paintings, dated between 1921 and 1935, were studied, with a focus on three works in the collection of the Fondation Beyeler (Basel, Switzerland)—Tableau I (1921–1925), Composition with yellow and blue (1932) and Composition with double line and blue (1935)—and on Lozenge composition with yellow lines (1933) in Kunstmuseum Den Haag (The Netherlands). Cross sections from other paintings, most of which previously studied by Van Asperen de Boer in the early 1990’s, were reexamined as well. The analyses revealed a zinc white paint with aluminum phosphate inclusions (ZW-Al/P). In two of the works, a zinc white paint with aluminum sulphate was also found. The occurrence of aluminum phosphate (or aluminum sulphate) in 1920–1930’s paint formulations, and in paintings by Mondrian, has never been reported so far. Likely, the use of this zinc white paint in Mondrian’s and other artworks is more widespread than currently known, but it may have been overlooked in similar case studies, since its identification can only be accomplished with detailed scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDX) analysis of cross sections. Mondrian’s use of pure ‘bright’ ZW-Al/P paint is limited to the later paintings (1932–1935) of this study, whereas in the earlier works (1921–1929) it was mostly mixed with lead white, likely conveying a different hue. Both the ZW-Al/P and Zn-Al/S ‘marker paints’ were also added to yellow, blue or black paint in specific paint layers of the planes and lines, respectively. It was also shown that Mondrian used the same paint on the frames as in the white planes and that the frames were painted while still working on the composition, and not only when he considered the work completed. Indeed, the detection of the zinc white marker paints might help to delineate the chronology of Mondrian’s working process in other paintings and may also be important in the interpretation of overpaints in the course of a treatment when removal of certain paint layers is considered.