Painted Metal Research Articles

Improvement of Technology of Formation of Coatings with Metal Effect by Modified Water-Dispersion Paints

The work is devoted to the study of the formation of protective and decorative coatings environmentally safe combined paint compositions. The considered work covers a range of issues related to colloidal-chemical modification of organo-soluble and water-dispersion lacquer compositions, development of their rational formulations and finishing modes, study of physical, mechanical and operational properties of protective coatings and ends with the calculation of the possible economic efficiency of the research results. In work environmentally safe water-dispersive paint and varnish compositions for transparent and opaque finishing by method of colloidal-chemical modification are developed. Optimal conditions for obtaining combined water-dispersion lacquer compositions of pigmented and non-pigmented and finishing modes are established. Modification of paint compositions with metal pigments allows to obtain a glazing coating, which significantly expands the color gamut of protective and decorative coatings.

Finite Element Modelling of Microelectrode Arrays of Mg and AA2024 Galvanic Couple

Aerospace aluminum alloys, such as AA2024-T3, are susceptible to microgalvanic corrosion and pitting due to its heterogeneous microstructure. Thus, they require additional corrosion protection methods. Magnesium rich primer coatings (MgRP) have emerged as an effective alternative to highly toxic chromate-based coatings. MgRP systems consist of an organic resin loaded with Mg pigment. The organic resin provides barrier protection, while metallic Mg pigment serves as a sacrificial anode by galvanic coupling with more noble Al alloy. The distance over which an active corrosion system can protect a defect exposing a metal surface is named galvanic throwing power and it is an important parameter used to evaluate the effectiveness of this type of protection method. Microelectrode array (MEA) is a technique commonly used to determine the galvanic throwing power. In this technique, wires of the metals of interest are mounted in a non-conductive matrix and the galvanic current distribution over the wires is measured. The wire diameter and the distance between the wires are important factors that affect the accuracy of MEA. While thin wires can provide finer spatial resolution, the experimental setup is challenging, and edge effects can decrease the representativeness of the measurement. Finite element analysis (FEA) is a tool used to predict both spatial and temporal potential and current distributions in electrochemical systems related to metal dissolution and cathodic reactions. FEA also can be used as an experimental design tool. In this work, FEA was used to assess important parameters and predict an optimal combination of wire diameters and distance between wires that result in higher accuracy of MEA. COMSOL Multiphysics (ver.5.4) was used to perform the finite element simulations. Potentiodynamic polarization scans of AA2024 and pure Mg immersed in 0.9 M NaCl solution were performed to generate E - i curves that were used as the electrochemical boundary conditions. Laplace equation was used to describe the current distribution that resulted from the galvanic coupling. The effect of the spacing between the wires and their diameters on the current distribution was studied. The results were compared to a reference solid plate configuration, where the two metals were in electrical contact.

A computational model for chemo-mechanical degradation of historical oil paintings due to metal soap formation

A large percentage of oil paintings in museum collections suffers from chemo-mechanical degradation phenomena that are primarily due to metal soap formation. Metal soaps result from the chemical reaction between metal ions present in the pigments and saturated fatty acids released by the oil paint. They appear as large protrusions that disfigure the surface texture, possibly triggering mechanical damage and flaking of the painting. Despite that these phenomena have been widely observed in situ, the interaction between chemical and mechanical degradation processes is far from being understood. This paper proposes a chemo-mechanical model to predict metal soap formation and the resulting chemo-mechanical damage in historical oil paintings. The chemical process is described by means of a diffusion-reaction model, whereby the spatial growth of the metal soap crystal takes place in a small reaction zone at the boundary of the crystal. Metal soap crystallization and growth, driven by the diffusion of saturated fatty acids and metal ions, result in a chemically-induced volumetric growth strain. This introduces stresses in the paint, ultimately promoting crack nucleation and propagation. The fracture process is simulated with a cohesive zone approach, using interface elements equipped with a traction-separation law. The mass flux-concentration relation at the interfaces is consistently specified as a function of the mechanical damage. A set of numerical simulations illustrates the capability of the model to predict metal soap crystallization and growth and the fracture induced in the paint. The study finally illustrates the influence of various chemical and mechanical parameters (i.e., the size of the metal soap nucleus, the mismatch in elastic stiffness parameters between the metal soap and paint materials, the fracture length scale of the paint material, the chemical growth strain and the reaction rate) on the chemo-mechanical degradation of the paint layer.

Spray printing and encapsulated liquid metal as a highly reflective metallic paint for packing products

In this strategy, liquid metal (LM) with a shiny metallic luster and an excellent optical property, was introduced as a novel metallic paint and coating to packing products and achieved decorative effects. We report a straightforward method via spray printing to fabricate a consecutive ultra-thin LM film on various product substrates. Then, the flexible LM film was coated with a transparent varnish layer, which was rather convenient for the LM paint to be storing, using and transporting. The thicknesses (25 µm) and the shapes of LM paint were well controlled. The flop index (FI=105), and reflectance (R=88.8%) data of the LM metallic paint were characterized. The results indicated that the LM metallic paint could provide a sparkling appearance and an abounding glossy. The deoxidized LM has a pronounced positive influence on the surface roughness, appearance, reflectance, and metallic texture. The LM metallic paint was highly desirable for potential applications in automotive enamel, motorcycle, toy and high-quality industrial coatings in the near future.

Heavy Metals Contamination in Water and Their Hazardous Effect on Human Health-A Review

The levels of heavy metals contaminations in water like, Pb, As, Cd, Hg, Cr, Ni etc. in various water sources as ground, surface, tap water etc. Variety of heavy metals, some of them are potentially toxic and are transferred to the surrounding environment through different pathways. The concentrations determined were more than the maximum admissible and desirable limit when compared with the National and International organizations like WHO (2008), USEPA, EUC, EPA. Water may become contaminated by the accumulation of heavy metals and metalloids through emissions from the rapidly expanding industrial areas, mine tailings, disposal of high metal wastes, leaded gasoline and paints, land application of fertilizers, animal manures, sewage sludge, pesticides, wastewater irrigation, coal, Electronic waste. Heavy metal toxicity has proven to be a major threat and there are several health risks associated with it. The toxic effects of these metals, even though they do not have any biological role, remain present in some or the other form harmful for the human body and its proper functioning.

Glint Rendering based on a Multiple‐Scattering Patch BRDF

AbstractRendering materials such as metallic paints, scratched metals and rough plastics requires glint integrators that can capture all micro‐specular highlights falling into a pixel footprint, faithfully replicating surface appearance. Specular normal maps can be used to represent a wide range of arbitrary micro‐structures. The use of normal maps comes with important drawbacks though: the appearance is dark overall due to back‐facing normals and importance sampling is suboptimal, especially when the micro‐surface is very rough. We propose a new glint integrator relying on a multiple‐scattering patch‐based BRDF addressing these issues. To do so, our method uses a modified version of microfacet‐based normal mapping [SHHD17] designed for glint rendering, leveraging symmetric microfacets. To model multiple‐scattering, we re‐introduce the lost energy caused by a perfectly specular, single‐scattering formulation instead of using expensive random walks. This reflectance model is the basis of our patch‐based BRDF, enabling robust sampling and artifact‐free rendering with a natural appearance. Additional calculation costs amount to about 40% in the worst cases compared to previous methods [YHMR16, CCM18].

Accelerated tests, a necessary complement of electrochemical assays to evaluate anti-corrosive coatings

Corrosion processes of painted metals may be monitored by accelerated and/or electrochemical assays. There is certain relationship between both types of test. Particularly, when using paint coatings with high barrier effect (R > 108 Ω cm2) and low dielectric capacity (C 106 Ω cm2 ensures kinetic inhibition of the corrosion process. The question arises when the values of the above-mentioned parameters differ from those and a realistic approach to the coating useful service life is needed. In this paper, it was demonstrated that, in such cases, accelerated and electrochemical assays complement each other. Accelerated tests are related to coating durability while electrochemical ones provide information about the degradation mechanism. To carry out this investigation, three anti-corrosive paints containing ecological pigments were prepared and their protective behavior evaluated in the salt spray chamber and by electrochemical impedance spectroscopy (EIS).

Analysis of a long term starved Pseudomonas aeruginosa ATCC27853 in seawater microcosms

The persistence of pathogenic bacteria in the marine environment has been thoroughly investigated. The potential threat that these microorganisms pose to public health in recreational waters has always been a concern. In this study, the persistence and the response of Pseudomonas aeruginosa ATCC27853 to starvation and osmotic stress were studied after its incubation in sterilized seawater during 12 months. Three different colonial variants were isolated: A7 after one month, and A81 and A82 after 8 months of incubation period. The incubation effect on the bacterial phenotype and genotype were studied by analyzing modifications in morphology, antibiotic and metal resistance, molecular typing (PFGE and MLST), pigment production and virulence factors. The starved variants showed three different colony forms, but an indistinguishable PFGE pattern and belonged to ST155, as P. aeruginosa ATCC27853. The starved variants maintained the susceptibility to the 13 tested antibiotics, with the exception of the imipenem-resistant A82 strain, which also showed a small colony variant phenotype and the highest values of tolerance to the CuSO4 + NaCl combination. Significant differences were detected in the pigment production, the elastase activity and cytotoxic potential of the starved isolates in comparison to P. aeruginosa ATCC27853. Long-term exposure to stress, such as the incubation in seawater, was shown to induce different responses in P. aeruginosa, including virulent and resistant phenotypes.

The case of the hydrating hydra: Examination and treatment of a Blaschka glass invertebrate model

ABSTRACTLeopold and Rudolf Blaschka were a father and son team of master glassworkers active in and around Dresden in the nineteenth and early twentieth centuries. They made realistic and accurate models of hundreds of invertebrate species which they sold to schools and museums all over the world. In preparation for an exhibition about the Blaschkas at The Corning Museum of Glass, the museum's conservation team carefully examined, cleaned, and, in some cases, reconstructed about 75 of these delicate and unique models. Although the models are primarily made of glass, other materials such as metal wires, shells, paper, glues, resins, and paints were also used. Time and fluctuating environments have caused the structurally fragile models to suffer from deterioration of many of the components, including the glass. The extremely thin glass and the sensitive surfaces of the models necessitated the development of innovative new treatments for minimally invasive cleaning, stabilization, and reconstruction. The microscopy and UV examination of one model provided interesting information about the deterioration and fabrication of Blaschka models. Treatment of this model included surface consolidation, dry brush and solvent cleaning, reassembly, and loss compensation with cast Paraloid B-72 film.

Analysis of the technological and morphological peculiarities of bronzed powders production from the swarf wastes

The object of research is the technology of practical production of metal powders from swarf waste of aluminum bronze with their subsequent use as pigments for printing processes. In the course of research, it is found that the developed surface of the swarf particles, numerous defects in the form of macro- and microcracks, splittings and pores, a specific microrelief are favorable prerequisites for their grinding. Experimental developments of fine structure have shown that in the process of swarf chips due to additional deformation, the dislocation density and the magnitude of the micro curvatures of crystal lattice of powder particles increases. The use of a rolling combine with a set of vibrating screens makes it possible to use further fine grinding of swarf waste. The study of the shape and state of the surface on optical and scanning microscopes provided the necessary information to explain the processes occurring during swarf grinding. The obtained result shows that micro-studies of the swarf formation zone in БаАЖ 9–4 makes it possible to study the texturing mechanism for the structural components of the alpha phase, the eutectoid in the formed chip. This made it possible to predict the nature of changes in the latter during grinding. The analysis of the nature of the destruction of the surface of the swarf elements of aluminum bronze in the grinding processes make it possible to confirm the inheritance of the morphological, structural, and physicochemical regularities of the latter by newly formed powder particles, as well as the possibility of obtaining a dispersed metallic pigment for use in the printing industry. The obtained positive results make it possible to implement experimental developments on the use of non-ferrous alloy swarf waste for the manufacture of metal powders. Due to this, it is possible to selectively grind the particles to the desired size and use the resulting powder fractions for their intended purpose. These wastes can be a very promising raw material for their use, despite the scale of created metal particle wastes from alloyed metals and alloys, especially in the context of the development of the newest resource-saving technologies in Ukraine.

Characteristics of pigments, modification, and their functionalities

AbstractNovel treatments of pigments with inorganic materials have tremendous industrial and commercial prospects. Specific treatment of pigment has a marked effect on its behavior during application. The treatment allows a broad modification of the surface characteristics of pigment particles which leads to improved functionalities. Surface modification of pigments is achieved via coating, polymerization with modifying reagent, treatment with derivatives or polymers, which alter either the optical, conductivity or dispersibility during processing and application. These and many other distinguishing factors that affect the characteristics of pigments such as the class, crystal structure, particle morphology, particle size, hiding power, pigment volume concentration, surface character, and surface treatment have been reviewed. Various organic pigments such as those from fungus and bacteria, and the various families of pigment types such as metallic pigment, light interference, and diffractive pigments which presents decorative quality such as leafing, nonleafing, pearlscent, and Fabry‐Perot effects on substrates have also been reviewed in addition to those from inorganic sources with emphasis on the structure and physiochemical modifications using metal and nonmetal Ions.

Pigments in American tattoo inks and their propensity to elicit allergic contact dermatitis

Tattoos have become increasingly common in the United States. Historically, tattoo inks were comprised of metallic pigments, which have the potential to cause allergic contact dermatitis. Data have been lacking on the current use of these pigments in tattoo ink. Identify pigments currently used in tattoo inks manufactured in or sold by wholesalers in the United States and investigate cases of allergic contact dermatitis caused by these pigments. Using specific key words, we performed an internet search. Pigment information listed in tattoo product inserts was collated and evaluated. In total, 1416 unique inks were surveyed. The average bottle of ink contained 3.0 pigments. We identified 44 distinct pigments, of which 10 contained metallic pigments, including iron, barium, zinc, copper, molybdenum, and titanium. The remaining 34 pigments contained carbon, azo, diketopyrrolopyrrole, quinacridone, anthraquinone, dioxazine, or quinophthalone dyes. A literature search revealed that 11 of the 44 (25%) pigments had been suspected to cause contact dermatitis. Five were confirmed by patch testing. These findings highlight the diversity of pigments currently used in tattoos. Relatively few inks contained metallic pigments to which allergic contact dermatitis has historically been attributed. Patch-test clinicians should be aware of these new pigments.

Light scattering from a drop with an embedded particle and its exploitation in the time-shift technique

This study is devoted to light scattering from drops with an embedded particle, as would be expected in an encapsulation/coating process or with spraying of metallic paints. A ray-tracing approach is taken, in which the polarization and intensity of all rays impinging onto a defined detector aperture are documented, allowing the signal generation arising from the drop passing through a plane wave or focused Gaussian beam to be simulated. For validation of the ray-tracing code, comparisons are drawn to scattering from pure liquid drops, obtained using the Lorenz–Mie solution. When using a highly focused incident beam, the scattering corresponds to the optical arrangement of the time-shift technique and allows the capabilities of that technique to measure drops with embedded particles to be explored. The resulting detector signals for a drop with an embedded spherical particle (encapsulated particles) or an embedded circular flake (metallic paint drop) have been simulated. These signals are compared with signals arising from pure liquid drops and features are identified which could be exploited for detecting the embedded particles using the time-shift technique.

Development of High Metallic Silver Water Borne Paint Using Next Generation Paint for Car

Development of High Metallic Silver Water Borne Paint Using Next Generation Paint for Car

Modulation of BTEX Bio - Remedial Activity by Molecular Triggering from Facultative Anaerobic Activity

BTEX (Benzene, Toluene, Ethylbenzene, Xylene) is widely reside in fuel and painting process, such as industrial metal painting. Due to their volatile character, it is easily emitted and recalcitrant in disintegration through aromatic property. These vapor inhaled and slow corruption the lipid membrane of the lungs tissue. Benzene and derivatives are thus more mutagenic and carcinogenic evaluated. The leakage of oil and spoil the soil and groundwater which arouse publi c concern about health respect. Therefore, it is crucial to develop high - efficiency of pollutant transformation, with aims to instant treatment of their toxicity or start remediation process. This study had screened several active isolates from bio - fixed b iofilms consortia were carried. The investigation concerns the supplement of electronic molecules for the remediation effect of BTEX were tried and the cultivation status of facultative anaerobic state were addressed. In highlight of finding with high acti vity consortium was enriched from humic acid eluted from compost of kitchen waste, add additional 400 mg/L BTEX compound over almost one year. Active isolate were compared by using different carbon source as electron donors with 31.2 μM substrate concentra tion. After the basal carbon source as humic acid and molasses was extra added and compared, remedial activity of the strain with 3 - 3> 3 - 1> 2 - 6 were compared. As a second level analysis, the remedial effects shown: methanol>glucose>indole acetic acid>indol e, indicated that the electromotive force might influenced by the grafting carbon chain, the length of carbon grafting, the influence of reducer as ferrous ions in medium, also the free benzoic compound interacted, dynamic directing the direction of electr on flux from humic acid or molasses, overall, humic acid, generally less conversion, believed only support electron mediation in other reaction. While molasses, macromolecular and exhibits a reducing power with glucose and methanol. However, it causes inva lid electronic flux into aromatic conversion but competitively switch to oxidative respiration. Resulted an invalid co - metabolism. The significant of remedial effect by grafting aromatics and soluble humic acid were demonstrated in this report.

Modulation of BTEX Bio - Remedial Activity by Molecular Triggering from Facultative Anaerobic Activity

BTEX (Benzene, Toluene, Ethylbenzene, Xylene) is widely reside in fuel and painting process, such as industrial metal painting. Due to their volatile character, it is easily emitted and recalcitrant in disintegration through aromatic property. These vapor inhaled and slow corruption the lipid membrane of the lungs tissue. Benzene and derivatives are thus more mutagenic and carcinogenic evaluated. The leakage of oil and spoil the soil and groundwater which arouse publi c concern about health respect. Therefore, it is crucial to develop high - efficiency of pollutant transformation, with aims to instant treatment of their toxicity or start remediation process. This study had screened several active isolates from bio - fixed b iofilms consortia were carried. The investigation concerns the supplement of electronic molecules for the remediation effect of BTEX were tried and the cultivation status of facultative anaerobic state were addressed. In highlight of finding with high acti vity consortium was enriched from humic acid eluted from compost of kitchen waste, add additional 400 mg/L BTEX compound over almost one year. Active isolate were compared by using different carbon source as electron donors with 31.2 μM substrate concentra tion. After the basal carbon source as humic acid and molasses was extra added and compared, remedial activity of the strain with 3 - 3> 3 - 1> 2 - 6 were compared. As a second level analysis, the remedial effects shown: methanol>glucose>indole acetic acid>indol e, indicated that the electromotive force might influenced by the grafting carbon chain, the length of carbon grafting, the influence of reducer as ferrous ions in medium, also the free benzoic compound interacted, dynamic directing the direction of electr on flux from humic acid or molasses, overall, humic acid, generally less conversion, believed only support electron mediation in other reaction. While molasses, macromolecular and exhibits a reducing power with glucose and methanol. However, it causes inva lid electronic flux into aromatic conversion but competitively switch to oxidative respiration. Resulted an invalid co - metabolism. The significant of remedial effect by grafting aromatics and soluble humic acid were demonstrated in this report.

Numerical investigation of sand-basalt heat storage system for beam-down solar concentrators

This study aims to investigate the performance of a novel combined receiver storage system (RSS) for beam down solar concentrator. The proposed system consists of large sand volume located at the ground underneath the secondary reflector of the beam-down tower. The top of the storage volume is covered by an absorber system which contains a thick black painted metal plate. The absorber plate absorbs the reflected solar flux and converts it to heat. The heat energy is then transferred to the storage media using metal rods. The performance of the thermal storage material of different mixing ratios of sand and basalt are investigated. The unsteady governing equations for the system are solved using a finite element heat transfer model. The model is validated and used to predict the temperature distribution inside the storage media of different conducting rods configurations. The utilization factor of the storage media for various cases is calculated and documented. The results showed that the utilization factor is in the range 0.53–0.73 depending on the conductive rods configuration and the sand – basalt mixture ratio.

Position-free monte carlo simulation for arbitrary layered BSDFs

Real-world materials are often layered: metallic paints, biological tissues, and many more. Variation in the interface and volumetric scattering properties of the layers leads to a rich diversity of material appearances from anisotropic highlights to complex textures and relief patterns. However, simulating light-layer interactions is a challenging problem. Past analytical or numerical solutions either introduce several approximations and limitations, or rely on expensive operations on discretized BSDFs, preventing the ability to freely vary the layer properties spatially. We introduce a new unbiased layered BSDF model based on Monte Carlo simulation, whose only assumption is the layer assumption itself. Our novel position-free path formulation is fundamentally more powerful at constructing light transport paths than generic light transport algorithms applied to the special case of flat layers, since it is based on a product of solid angle instead of area measures, so does not contain the high-variance geometry terms needed in the standard formulation. We introduce two techniques for sampling the position-free path integral, a forward path tracer with next-event estimation and a full bidirectional estimator. We show a number of examples, featuring multiple layers with surface and volumetric scattering, surface and phase function anisotropy, and spatial variation in all parameters.

Cold Bonding Method for Metallic Powder Coatings

An efficient and simple method for preparing bonded metallic powder coating is in high demand in the paint manufacturing and application industries. The bonding purpose is to keep the mass percentage of metallic pigment consistent between the original and recycled coating powder, which aims at solving the problem of recyclability. One possible method capable of realizing this goal is using the binder to cohere metallic pigment with base particles through a cold bonding method. Through this approach, the pre-curing and high-reject-rate problems generally present in thermal bonding can be completely eliminated. In this paper, polyacrylic acid (PAA) and polyvinyl alcohol (PVA) are applied as binders for the bonding process. At various dosages of liquid binder and D.I. water, bonded samples with different bonding effect were prepared. Finally, a good bonding quality with the lowest variance between the mass concentrations of Al flakes in the original powder (before spray) and deposited powder (after spray) 2.94% with PAA as a binder and 0.46% with PVA as a binder was achieved. These results manifest that the cold bonding method is a green and simple approach for preparing the metallic powder coating.

Temperature and emissivity retrieval from low-emissivity materials using hyperspectral thermal infrared data

ABSTRACTLand surface temperature and emissivity separation (TES) is a key problem in thermal infrared remote sensing. Many TES algorithms have been proposed and validated on natural surface materials such as water or vegetation. However, when those algorithms are applied to low-emissivity materials such as some metals, the retrieval accuracy needs significant improvement. Here, we propose a new temperature and emissivity retrieval algorithm for hyperspectral thermal infrared data based on bias characteristic of atmospheric downward radiance. This approach is aimed at weakening the large influence of errors in atmospheric downward radiance on the TES of low-emissivity materials due to stronger coupling between the surface and atmosphere. Compared with traditional approaches such as the iterative spectrally smooth temperature and emissivity separation (ISSTES) method, the proposed method improves retrieval accuracy for low-emissivity materials by about 0.3, 0.4, and 1 K for three low-emissivity test materials (galvanized steel metal, metallic silver paint, and gold paint sandpaper). Thus, the proposed algorithm can weaken the influence of atmospheric downward radiance error. In addition, the computation efficiency is higher than ISSTES because fewer groups of channels are involved in the calculation.