Hasil untuk "Paints, pigments, varnishes, etc."

Antonio Kruljac, Anka Ozana Čavlović

Many materials used in wood industry are considered to have carcinogenic or mutagenic effects, which is a health risk for workers in production. Carcinogenic chemical compounds, apart from causing cancer, also pose a great risk for human health in other terms like respiratory issues, skin irritation, allergic reactions, congenital abnormalities in women, visual impairments, immune system and neurological disorders, hormonal imbalances, etc. Carcinogenic pollution in the wood industry is associated with activities related to the emission of wood dust, production of panel materials, drying and steaming of wood, sharpening tools, the activities of handling glues, paints, varnishes, coatings, wood preservatives, exposure to fossil and biofuel exhaust gases, and many others. The purpose of this paper was to present the carcinogenic substances to which workers in the wood industry are professionally exposed, to present previous research and currently valid regulations and protection measures in the EU. By reviewing the sources, it can be concluded that, although legislation often requires clearly defined etiological factors, scientists agree that the understanding of the relationship between occupational exposures and cancer is not yet complete and that occupational carcinogenic factors are considered occupationalexposures if a significant number of workers were exposed to significant levels.

K. G., Vajravelu Kuppalapalle, R. Kudenatti

The Carreau fluid behavior is observed in multiple practical applications and a few familiar processes, such as blood flow, sewage sludge, due to paints or varnishes, waxy crude oils, etc. Its wide range of applications motivates us to focus on the two‐dimensional laminar Carreau flow past an inclined stretching cylinder in the current analysis, which is significant in biomedical engineering and industrial processes. Additionally, real fluids are sensitive to temperature, and hence their thermal conductivity fluctuates with the surrounding temperature. Therefore, to attain a more reliable result in the present study, the thermal conductivity of the fluid is assumed as a function of temperature, and the model is influenced by the oblique magnetic field that is applied to the system externally. The flow model is mathematically framed through partial differential equations. The finite difference technique is adopted to discretize the governing equations. The original nonlinear system of equations is linearized using a quasi‐linearization scheme. The strong convergence criteria are implemented in the code to ensure the convergence of the computational results. The final outcomes are extracted using the Thomas algorithm. The flow characteristics are studied and interpreted physically under the influence of different emerging parameters. The friction factor and heat transfer rate are also computed with an engineering interest. At a high shear rate, the flow characteristics are found to be higher in Newtonian fluid than in non‐Newtonian fluid. The fluid velocity and temperature are altered with the angle of oblique cylinder, and they are higher with a lower angle of inclination. The flow parameters that influence the streamlines and isotherms are illustrated and discussed. It is concluded from the computations that the higher angle of inclination of the cylinder reduces the frictional force due to the fluid flow and increases the heat transfer rate near the wall. Also, when the oblique angle of the magnetic field is enhanced, the skin‐friction coefficient reduces, and the heat transfer rate increases in both the Newtonian and non‐Newtonian fluid flows.

M. S. Delyagina, L. G. P’yanova

The paper summarizes literature data on the properties and application of pigment carbon black. It is shown how the addition of carbon black affects the color and quality of paints and varnishes. Technical carbon by its nature, physicochemical, physical properties is the most suitable pigment for the production of black and gray varnishes and paints, it is compatible with film-forming substances and other components of paint and varnish compositions.

Y. Han, Na Ra Lee, Young Mok Kim et al.

Guard Dog II (1969–1970) by Jean Dubuffet is an artwork that shows the characteristics of the artist's l'hourloupe period (1962–1974). This study revealed the materials and manufacturing techniques used by the artist at the time through material analysis of Guard Dog II, and suggested an appropriate conservation treatment method for the work through a cleaning test. Dust, stains, discoloration, cracks, etc. were observed on the surface of the artwork and stains were particularly severe and discoloration required conservation treatment. Prior to treatment, multiple analytical approaches such as Fourier transform infrared spectroscopy, Raman spectroscopy and gas chromatography/mass spectrometer were applied to identify the materials of the paint layers and confirm the state of the conservation of the artworks. As a result, it was confirmed that polyurethane paint was used in the artwork, and the pigment used for each color was also identified. For the stable conservation treatment of the artwork, the chromaticity, glossiness and workability of the cleaning materials were evaluated, and it was found that isopropyl alcohol and nonionic surfactant were suitable for cleaning. The conservation treatment was performed based on results from the cleaning test, and the artwork was restored cleanly. Since most of the existing research on cleaning methods has been focused on painting, this study contributes to the conservation of sculptures by suggesting cleaning methods suitable for three-dimensional colored objects. The materials and production techniques used in Jean Dubuffet, Guard Dog II were confirmed. As cleaning materials for deteriorated artworks, isopropyl alcohol and non-ionic surfactants are effective. Hydrogels are not suitable for this work due to the type and characteristics of the gels. The materials and production techniques used in Jean Dubuffet, Guard Dog II were confirmed. As cleaning materials for deteriorated artworks, isopropyl alcohol and non-ionic surfactants are effective. Hydrogels are not suitable for this work due to the type and characteristics of the gels.

Arja Källbom, Austin Nevin, F. Izzo

The characteristics of armour paints, historically used to protect ferrous industrial heritage, are explored. Amour paints contain lamellar and highly reflexive pigments of micaceous iron oxide (MIO) and metallic, leafing aluminium, bound in linseed oil and linseed oil–tung oil mixtures, on an inhibitive and soap-forming linseed oil primer (red lead). It is the first study of the binding media used for historical armour paints and investigates the chemical and physical ageing of armour paints using a multianalytical approach. Naturally aged examples are compared to accelerated aged replica armour paint, and to historical paints. The ageing and degradation reactions are assessed by complementary GC–MS and FTIR, together with measurements of wettability, hardness and surface colour. The historical paint formulations include linseed oils and alkyd binders. The results confirm that the leafing effect of aluminium pigments results in only a small concentration of binder at the surface: the paints studied reflect light and form a strong chemical and physical barrier. Linseed oils and tung oil mixtures have been proven to be suitable for the production of armour paints, but the evaluation of ageing and assessment of physical changes will require further investigation.

سارا خمسه, الهه شریفی, محسن محمد رائی نایینی

الماس در مقایسه با سایر مواد، دارای خواص فیزیکی بسیار ‌ویژه‌ای ‌می‌باشد. علیرغم این ویژگی‌ها، کاربردهای عملی آن در صنعت، به علت کمیابی و قیمت بالا، بسیار محدود است. با توجه به پیشرفت‌های اخیر فناوری، تهیه پوشش‌های نازک الماس مصنوعی بر سطح بسترهای مختلف امکان‌پذیر گشته است. به عنوان مثال، اعمال یک لایه الماس مصنوعی به روش ‌رسوب‌دهی شیمیایی از فاز بخار (CVD) بر سطح ابزارهای مورد استفاده در صنعت ماشین‌کاری، منجر به بهبود کارایی این ابزارها خواهد شد. در حال حاضر تقاضای استفاده صنعتی از پوشش‌های الماس مصنوعی، به دلیل خواصی چون مقاومت سایشی بالا، سختی فوق العاده و ضریب اصطکاک کم، به شدت افزایش یافته است و تحقیقات وسیعی جهت رفع عیوب، بهبود خواص و گسترش این دسته از پوشش‌ها در جریان ‌می‌باشد. با این حال، یکی از مشکلات عمده پوشش‌های الماس مصنوعی این است که این پوشش‌ها تحت بارگذاری بالا از سطح قطعه جدا ‌می‌شوند; به همین جهت تلاش محققان، بر افزایش چسبندگی این پوشش‌ها تمرکز یافته است. لازم به ذکر است که به منظور دستیابی به چسبندگی مناسب در این پوشش‌ها، می‌بایست بسیاری از خصوصیات ‌سامانه پوشش- بستر، از قبیل ضخامت بهینه پوشش و به حداقل رساندن تنش حرارتی پسماند، در نظر گرفته شود. بنابراین، به منظور دستیابی به پوشش‌های الماس مصنوعی با خواص منحصر بفرد، لازم است که ریزساختار و معماری پوشش‌ها به دقت طراحی گردد. هدف از مقاله حاضر، بررسی تحقیقات صورت گرفته در زمینه مشخصه‌ها و بهبود عملکرد این خانواده مهم از پوشش‌های محافظ، ‌می‌باشد.

H. Onoda, R. Sasaki

Recently, the use of harmful metals has been restricted in the world. However, because suitable substitutes have not been obtained, some materials containing harmful metals have been used in many fields [1-4]. For example, the inorganic color pigments containing metals such as mercury, cadmium, and lead have some merits, including high light stability, heat-resistant coloring visibility, cost, etc. [5-7]. In addition, because the oxide pigments have low coloring and covering, they are difficult to use for paints and plastics [8]. The sulfate and nitrate pigments have a lower heat resistance than oxide pigments and require harmful and/or combustible gas to synthesize. Furthermore, it is difficult to prepare the sulfide and nitrate pigments with repeatability [9, 10]. Therefore, the novel inorganic pigments are required with suitable properties and without difficult production methods [11, 12]. There are some kinds of inorganic blue pigments that are available for use, for example, Prussian blue, mixed metal oxide, cobalt blue, cerulean, cobalt-chromium blue, and so on [13-16]. Some of these pigments also include harmful metals. Therefore, novel blue pigment without harmful and precious metals is required. We focus on the natural ore, turquoise, CuAl6(PO4)4(OH)8.4H2O, because this ore includes no harmful and precious metals [17, 18]. Natural ores have high light stability and heat resistance. Because of their solidity, they are expected to have applications for plastics, paint, ceramics, and so on. In a previous study, we prepared novel inorganic pigments imitating turquoise, CuAl6(PO4)4(OH)8.4H2O, from copper oxide, aluminum hydroxide, and phosphoric acid by heating [19]. The obtained materials had the X-ray diffraction (XRD) peaks of CuAl6(PO4)4(OH)8.4H2O and CuO. However, the color of samples was dark, therefore, a different process is required to prepare the novel blue inorganic pigments. In this study, novel inorganic pigments imitating turquoise were synthesized by mixing copper nitrate solution, aluminum hydroxide or nitrate solution, phosphoric acid, and sodium hydroxide solution, and then heated to repress their solubility. The obtained materials were estimated from the viewpoint of pigment. Preparation of novel blue phosphate pigments in imitation of turquoise

Gyu-Seong Cho, Kwangwoo Kim, W. Park

F. Babick, M. Stintz, T. Koch

Abstract The functionality of pigments and fillers is significantly affected by their state of dispersion at the point of application (e.g. in paints and varnishes). This state depends on the materials' original state of agglomeration and aggregation and on their processing, which typically aims at desagglomeration and partial disintegration by high shear stresses. In order to assess the dispersibility of pigments and fillers, a characterisation method is proposed, which comprises sample preparation by ultrasonic dispersion (USD) and particle size analysis by means of analytical centrifugation (AC). The characterisation method is tested within an interlaboratory comparison for four inorganic powders and involves different USD equipment and different AC techniques in different laboratories. The analyses delivered volume-weighted particle size distributions, which were statistically evaluated in order to assess the uncertainty of results within a laboratory and to quantify the variation among the different laboratories. Impacts of the material on the performance of the characterisation method are discussed as well as differences between the various AC techniques.

Zh.A. Sapronova, D. Sapronov, Yu.L. Starostina

Xue Yu, Lyuting Zhao, T. Gui

V. Voitovich, M. Kart, E. A. Zakharychev et al.

T. Špec, Sebastijan Peljhan, J. Vidič et al.