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For the first time, we establish indirect dependences for the analytic evaluation of the thicknesses of coatings formed by synthetic diamond powders for new 3D models of their grains. We perform the comparative analysis of the errors introduced in the evaluation of the coating thickness by the proposed new and known 3D models of grains and the corresponding analytic dependences. We also formulate the directions of our subsequent investigations in this field. [ABSTRACT FROM AUTHOR]

The process of spray drying is regarded as a method that conventionally converts fruit juices like orange juices or concentrates to the powder fruit form. In this process, three main processes are involved in spray drying (Murungesan et al. [29]). These processes are: • Atomization • Droplet --hot air contact and evaporation of moisture. • Separation of products that have dried from the exit air Feed • Orange concentrates and lemon concentrates with water (slurry mixture) Output • Orange fruit powder • Lemon fruit powder In this study's scope, we investigated the procedures within the fruit drying spray responsible for yielding fruit powders using orange and lemon fruit concentrates. The production of fruit powder from fruit condenses calls for the use of drying aids, which function as an agent for reducing stickiness concerns that arise during the fruit spray drying technique. This paper illustrates the process of fruit spray drying with orange and lemon fruit concentrates and how the fruit powder form can be used in a production application (Boonyai et al. [35]). The concentrated orange and lemon juice are spray-dried using air that is dehumidified as a medium for drying, and the agent used for drying is maltodextrin. For the spray drying process, the piloting-scale dryer is used. [ABSTRACT FROM AUTHOR]

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on defatted house cricket (Acheta domesticus) powder as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is proposed as dry powder. The main components of the NF are protein, fat and fibre (chitin). The Panel notes that the concentration of contaminants in the NF depends on the occurrence levels of these substances in the insect feed. The Panel further notes that there are no safety concerns regarding the stability of the NF if the NF complies with the proposed specification limits during its entire shelf life. The NF has a high protein content, although the true protein levels are overestimated when using the nitrogen‐to‐protein conversion factor of 6.25 due to the presence of non‐protein nitrogen from chitin. The applicant proposed to use the NF as food ingredient in a number of food products. The target population proposed by the applicant is the general population. The Panel notes that, considering the composition of the NF and the proposed conditions of use, the consumption of the NF is not nutritionally disadvantageous. The Panel notes that no genotoxicity and no subchronic toxicity studies with the NF were provided by the applicant. Considering that no safety concerns arise from the history of use of the source of the NF (A. domesticus), and the limited difference between the whole insect and the partially defatted NF, the Panel identified no other safety concerns than allergenicity. The Panel considers that the consumption of the NF might trigger primary sensitisation to A. domesticus proteins and may cause allergic reactions in subjects allergic to crustaceans, mites and molluscs. Additionally, allergens from the feed may end up in the NF. That aside, the Panel concludes that the NF is safe under the proposed uses and use levels. [ABSTRACT FROM AUTHOR]

Amorphous alloys have high strength and high hardness, showing their potential applications as tribological materials. In order to improve the wear resistance of 316L stainless steel (SS), Fe-based amorphous powder was deposited on 316L SS by laser cladding. Since the microstructure of the laser clad coating was sensitive to the dilution between coating and substrate, multilayer Fe-based metallic coatings were fabricated layer by layer. When the laser cladding layer number increased, the microstructure evolved from a complete crystalline phase to a mixed structure with amorphous phase and dendrite. Meanwhile, the amorphous content increased and the average microhardness was enhanced. Accordingly, the wear resistance was improved generally under all the sliding conditions, including in air, distilled water, and simulated body fluid (SBF) solution. For the lubricant effect of liquid, the coefficients of friction in distilled water and SBF solution are relatively lower than that in air. Compared with 316L SS, the volume loss rate of nine-layer coating decreased by two orders of magnitude in air and about 5.5 times in SBF solution. Except for one-layer coating, the predominant wear mechanism of the laser clad coatings in air is abrasive wear accompanied by oxidative wear. The wear mechanism in SBF solution is dominated by abrasive wear and corrosive wear. The superior hardness and good corrosion resistance are responsible for the outstanding wear resistance improvement. Therefore, the laser clad coating with Fe-based amorphous alloy has a potential application in the surface strengthening of mechanical parts or metallic implants. [ABSTRACT FROM AUTHOR]

The problem of sluggish combustion reactivity of Boron (B) can be overcome by inclusion of fluoropolymers. In this paper, three commercial fluoropolymers; PVDF (59 wt% F), Viton (66 wt% F) and THV (72 wt% F) coated (Ca. 4 wt%) B powders (Ca. 1-µm in size) were prepared and their combustion characteristics have been investigated. Among the fluoropolymer-coated powders, THV coated B provided the highest average improvement in heat of oxidation, reactivity in terms of pressure generation and combustion temperature followed by Viton and PVDF coated B. The sequence of reactivity enhancement has been explained by the variances in gasification efficiencies of the boric oxide shell, induced by the thermal decomposition of the respective fluoropolymer coatings. THV with higher fluorine and lower hydrogen content, supposedly promotes better gasification of the boric oxide shell by releasing more fluorine rich alkanes/alkenes during thermal decomposition. However, PVDF predominantly produces HF, which apparently less effective in gasification of the boric oxide shell, resulting in limited improvement of the measured properties. [ABSTRACT FROM AUTHOR]

In this work, tris(oxiran-2-ylmethyl) benzene-1,3,5-tricarboxylate (TOTC) was synthesized by a new two-step method without using harmful epichlorohydrin and served as a curing agent for polyester powder coatings. The chemical structure of TOTC was determined by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The curing behavior and the curing reaction kinetics of TOTC/polyester resin (NH-3307) system were studied by dynamic differential scanning calorimetry. The activation energy Ea was 71.75 kJ mol-1 according to Flynn–Wall–Ozawa method, and the curing reaction of TOTC/NH-3307 system was described by Friedman method. It was found that the curing reaction of TOTC/NH-3307 system was a two-parameter autocatalysis which followed the Šestάk–Berggren model. The nonisothermal curing reaction rate was simulated according to the Šestάk–Berggren model and the experimentally parameters. What is more, the thermogravimetric analysis results showed that the TOTC/NH-3307 system had good thermal stability with an initial decomposition temperature of 374.92°C. The TOTC/NH-3307 cured film exhibited excellent leveling performance by SEM. The results demonstrated that TOTC has efficient curing ability and huge market potential. [ABSTRACT FROM AUTHOR]

Titanium materials are widely used in aviation; their poor wear resistance and easy high-temperature oxidation defects limit their further application. Cold spraying technology is an excellent way to solve these defects, has essential significance for its surface research. This study reports the deposition mechanism of Aluminium (Al) + Titanium (Ti) mixed powders deposited onto Ti6Al4V by cold spraying technology using Abaqus/Explicit. Because of its high surface hardness, it is not easy to obtain effective deposition by direct spraying with pure Al powder. Hence, Ti powder as the intermediate coating was proposed between Ti6Al4V and pure Al powder. Since there are few reports on numerical simulation of mixed particles, most studies focus on single or multi-particles of the same material. The critical process of numerical simulation of mixed powders is emphasized in detail. Using the recovery coefficient is defined to determine the critical speed. The results show that it is feasible to determine the critical velocity of mixed powder through the smaller value of recovery coefficient from the perspective of energy. In this paper, the recommended critical speed of mixed powder is 500 m/s-900 m/s. It will provide theoretical guidance for researchers and is of great significance to further expand the application of other mixed powders. [ABSTRACT FROM AUTHOR]

Developing new coating modification technology of aluminum nitride (AlN) powder for higher hydrolysis resistance is the key to prepare high-performance AlN ceramic substrate with water-based wet process in the future. In the this paper, The poly(vinyl pyrrolidone)-b-poly(Styrene/Itaconic anhydride) (PVP-b-P(St/ITA))block copolymer with PVP as the independent chain segment was designed and synthesized through reversible addition fragmentation chain transfer (RAFT) polymerization, which was used for the study on coating modification, hydrolysis resistance, and dispersion performance of AIN powder. The study results show that, when using PVP macromolecular chain transfer agent (PVP-CTA) for the RAFT chain extension and polymerization in St/ITA binary system, the molecular weight increases linearly and the molecular weight distribution tends to decrease with the monomer conversion rate, which is in line with the activity-controlled characteristics of RAFT polymerization. The copolymer PVP-b-P(St/ITA) was used to for surface modification treatment of submicron AlN powder to generate esterification reaction, which was absorbed and bound to the powder surface. Hydrolysis resistance and dispersion experiments were conducted for modified powder, and the crystal phase and micro structure of modified powder were analyzed and observed through XRD, SEM, and TEM. It was found that copolymer modification had no effect on the powder crystal phase. A 8–21 nm passivation layer was coated on the surface, which can exist stably for 10 h in 60 °C water. Zeta potential and laser particle analyzer tests showed that modified powder featured excellent water-based slurry dispersion performance, and certain self-dispersing characteristics. The highest Zeta potential appeared in pH 6~7, and the particle granularity was distributed uniformly with the median particle diameter of 875 nm. The powder hydrolysis resistance and dispersion performance are significantly improved. [ABSTRACT FROM AUTHOR]

Dioctyl sebacate (DOS), paraffin (PW), fluororubber (FR), and polyurethane (PU) are widely used as binders in aluminized propellants and explosives. In this study, ignition and combustion of aluminum powders coated with DOS, PW, FR, and PU are investigated. The flame speeds of the aluminum powders coated with DOS, PW, and PU are found to decrease with an increase in the content of these binders. The flame speed of the aluminum powder coated with FR is greater than those of the aluminum powders coated with DOS, PW, and PU. In this case, combustion improvement is due to the reaction between the alumina shell and FR. [ABSTRACT FROM AUTHOR]

Abrasion of cultivator equipment parts working in the soil causes serious losses if necessary precautions are not taken. The cultivator blades used to plow the soil in agricultural production wear out over time. In order to reduce this wear, the hardness and wear resistance of the material should be increased first. In this study, some of the 30MnB5 cultivator blades were heat-treated and some were coated with HVOF technique. The samples were obtained by plowing the soil at 15-cm working depth and 5.4-km ⋅ h − 1 forward speed in two fields with different soil moisture contents. As a result of the experiments, abrasion losses and surface deformation of the blade material were observed and the effect of soil moisture on wear was also determined. After the treatment of 49.5 daa (decare) with soil at 9% moisture content, the heat-treated 30MnB5 sample was worn 5.6 g, and the sample coated with WC–10Co–4Cr was worn 3.2 g. Abrasions at 14% soil moisture were 6.3 g and 3.6 g, respectively. It was observed that the coated material was less corroded than the heat-treated material. While the results obtained will contribute to the prevention of economic losses, the release of metals into the soil will also be prevented. [ABSTRACT FROM AUTHOR]

Electrostatic coating is being developed as an attractive alternative to overcome the problems encountered during conventional coating which includes non‐uniform coating, dust generation, high energy and time consuming, equipment cleaning, and operating expenses. In this method, powder particles are charged by passing through an ion‐rich region, which repel each other to produce an evenly distributed coating. This results in a uniform distribution of powder on target surface. In this study, the electrostatic coating of black pepper powder was applied by varying the applied voltage (0–20 kV), at a conveyor belt speed of 10 m/s and compared with manually coated cheese slices. The values of transfer efficiency (52.7%–87.0%), dust reduction (76.2%–85.8%), and adhesion (20.8%–85.3%) were higher for electrostatic coatings. The weight losses were lower (0.19%) at 15 kV as compared to 20 kV (0.67%). The total plate count of cheese slice coated at 20 kV was significantly higher (p < 0.05), whereas at 15 kV it was lower than all other treatments. The shelf life of coated cheese slices at 15 kV lasted up to 1 month due to better coating compared to other treatments. From the results, it can be concluded that electrostatic coating of cheese slice with black pepper is best at 15 kV along with higher transfer efficiency and dust reduction. Practical Application: Electrostatic powder coating of cheese resulted in higher transfer efficiency and reduction in dust production. later one has reduce the coating material requirement, thereby, reducing the processing cost. Moreover, dust reduction will reduce the burden of cleaning cost of environment and enhance worker health. [ABSTRACT FROM AUTHOR]

Indonesia is one of the major countries which contributes the world's guava production. Guava var. Getas Merah is commonly found in Indonesia. Guava has a short shelflife as it rapidly goes under postharvest ripening. This leads to a faster deterioration of physicochemical and sensorial properties of guava. A generally used method to extends shelflife is by edible coating. In this study, a combination of alginate and Cyclea barbata leaves powder (CBLP) was investigated as a potential edible coating. The analysis of firmness, total soluble solids, total reducing sugar, total titratable acidity and organoleptic tests were conducted to evaluate the quality of guava fruits stored for 20 d at 14°C. A split plot design study was used and four different treatments with different CBLP concentrations were applied. The samples treated with 2% alginate and 0.8% CBLP showed the lowest total dissolved solids, total reducing sugar, and total titratable acidity. Moreover, the samples were reported with the highest score on color, taste, and texture parameters. The firmness test showed that samples treated with 2% alginate and 0.2% CBLP had the lowest firmness loss and highest score for aroma. In summary longer quality retention of guava fruits was found after the addition of CBLP in alginatebased edible coating. [ABSTRACT FROM AUTHOR]

The coating industry is gradually developing towards a green and efficient direction. Powder coating has the advantages of energy saving, nonpolluting, high efficiency, and easy production automation. Its output has grown rapidly and has become one of the development directions of the coating industry. Powder coatings have expanded into new end markets with their well-known advantages. In order to analyze the preparation conditions of low-temperature curing powder coatings, this study selects low-temperature curing powder coatings and ordinary powder coatings to compare, analyzes the realization mechanism of low-temperature curing powder coatings, and uses actual cases for research and analysis. Low-temperature curing powder coatings were prepared with trimethylolpropane (TMP) as the main raw material. Using a combination of single-factor analysis and orthogonal experiments, the effects of TMP addition, curing temperature and curing time on the gloss and impact properties of coatings were studied, and a local clustering algorithm was proposed to intelligently determine the optimal coating condition. Low-temperature curing powder coatings are optimized and screened by algorithms. [ABSTRACT FROM AUTHOR]

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Over the last decade, the conical mill has emerged as a potential piece of equipment to use for continuous dry coating pharmaceutical powders. In this work, silicon dioxide was used as a guest particle on two excipients, fast flow lactose (FFL) and grade PH200 microcrystalline cellulose (MCC), for dry coating by a conical mill with a modified screen that permitted batch and continuous mode operation. Samples were pre-processed in a V-blender. SEM images, particle size distribution, and EDS mapping were used to characterise the treated powders. Pre-processed samples showed some discrete coating of the host particle. After batch processing, the samples were covered with a complete coating. When processed at high impeller speed, coating of FFL was a mix of A200P and FFL fines generated by attrition. Continuous mode processed samples, which had a lower processing time, were coated discretely and showed a better coating than the pre-processed samples. Increasing guest/host mass ratio with FFL host particle had a positive impact on the quality of the coating. These results help to build the case that the processing time of the conical mill is a key parameter to the success of the conical mill as dry coating equipment in the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Fluorescent coatings have attracted attention due to their bright colors. However, they have fewer outdoor applications due to low stability, especially the poor weather resistance of the fluorescent pigments. In order to improve their weather resistance and maintain the excellent appearance, this study used polymer binders to coat a light shielding agent nano TiO2 on the surface of the fluorescent pigment to extend the durability. Three organic binders, polyester varnish, polyurethane varnish, and polyvinyl alcohol, were selected. Each binder was dissolved and mixed with pigments and nano TiO2 particles to make a polymer-TiO2 layer on the pigment surface. The effects of binder types and loadings were investigated and evaluated by accelerating weather test of corresponding fluorescent powder coatings. According to SEM and ash test, nano TiO2 was successfully coated on the surface of fluorescent pigments. The modified fluorescent pigment shows a strong ability to absorb ultraviolet rays, and the weather resistance of prepared coatings has been significantly improved compared with the original fluorescent powder coating. When using clear coat PE as a binder and setting the ratio of the binder to the nano TiO2 of 1:2, the UV exposure time of fluorescent powder coatings can be extended by over twelve times compared to the coatings with original pigment for the same color change. This study provides an effective approach to enhance the weather resistance of fluorescent coatings and thus expand their applications. [ABSTRACT FROM AUTHOR]

In this study, electrolytic coating of pure chromium and Cr-ND (nanodiamond) composite coatings were applied on pre-alloy metal powder metallurgy specimens. The effects of the coating conditions including the ND particles content and coating duration in the bath on tribological behavior of the chromium coatings were investigated. Characterization tests were executed using an optical microscope, SEM, EDS, XRD and AFM. The hardness and wear resistance of the Cr-ND coated samples were compared with pure chromium coated and non-coated specimens. After determination of the suitable coating conditions, a 1.2‑liter engine motor oil pump sprocket was chosen as an industrial application for the coating. The sprocket manufactured by pressing and sintering under the same conditions. The wear test of the sprocket was accomplished by using a new designed test configuration to simulate the actual working conditions with motor oil. The wear resistance of the Cr-ND coated samples and sprockets were compared with pure Cr coated, non-coated and induction hardened ones. The results demonstrated that the embedding of the ND particles in the chromium matrix led to an improvement on the hardness and wear behavior of the Cr-ND coatings in comparison to pure chromium coatings, noncoated and heat-treated specimens. [ABSTRACT FROM AUTHOR]

Schematic illustrations of preparation processes of the heterostructural Sn/SnO 2 @NC microcube anode. [Display omitted] • SnO microcubes are successfully fabricated via a hydrothermal process. • SnO is easily transformed into Sn and SnO 2 at a high temperature in the inert atmosphere. • The Sn/SnO 2 @NC electrode presents enhanced cycling performance and improved rate performance. • The improved performance can be ascribed to the heterostructure and the NC layer. The nitrogen-doped carbon (NC) coating encapsulating heterostructural Sn/SnO 2 microcube powders (Sn/SnO 2 @NC) are successfully fabricated through hydrothermal, polymerization of hydrogel, and carbonization processes, in which the SnO precursor powders exhibit regular microcube structure and uniform size distribution in the presence of optimized N 2 H 4 ·H 2 O (3.0 mL of 1.0 mol/L). Interestingly, the precursor powders are easily subjected to a disproportionated reaction to yield the desirable heterostructural Sn/SnO 2 @NC microcube powders after being calcined at 600 °C in N 2 atmosphere in the presence of home-made hydrogel. The coin cells assembled with the Sn/SnO 2 @NC electrode present a high initial discharge specific capacity (1058 mAh g−1 at 100 mA g−1), improved rate capability (an excellent D Li+ value of 2.82 × 10-15 cm2 s−1) and enhanced cycling stability (a reversible discharge specific capacity of 486.5 mAh g−1 after 100 cycles at 100 mA g−1). The enhanced electrochemical performance can be partly ascribed to the heterostructural microcube that can accelerate the transfer rate of lithium ions by shortening the transmission paths, and be partly to the NC coating that can accommodate the volume effect and contribute to partial lithium storage capacity. Therefore, the strategy may be able to extend the fabrication of Sn/SnO 2 heterostructural microcube powders and further application as promising anode materials in lithium ion batteries. [ABSTRACT FROM AUTHOR]

In the present work, dense ZrB2‐based monoliths were produced via hot‐pressing of ZrB2 powders coated with amorphous polymer‐derived SiCN, SiZrCN, or SiZrBCN at relatively moderate temperatures (i.e., 1800℃). Thus, ZrB2 particles were embedded in polymer‐derived ceramic shell were realized by coating their surface with the corresponding polymeric precursors (polysilazane, Zr‐modified polysilazane, Zr‐ and B‐modified polysilazane, as for SiCN, SiZrCN, and SiZrBCN; respectively), followed by cross‐linking at 200℃ and pyrolysis at 1100℃ in Ar atmosphere. The obtained monolithic samples were carefully characterized concerning their phase composition and microstructure. Typically, the densified samples exhibit a homogeneous microstructure consisting of ZrB2 grains and a multi‐phasic polymer‐derived ceramic grain boundary phase (β‐SiC, t‐BCN, ZrO2, and ZrC). The prepared monoliths exhibited fair hardness values, that is, 12.5, 14.2, and 13.3 GPa for ZrB2/SiCN, ZrB2/SiZrCN, and ZrB2/SiZrBCN. [ABSTRACT FROM AUTHOR]

A cost-effective procedure to surface alloy WCB steel butterfly valve sand castings using mold coatings incorporating metal and ferroalloy powders has been described. The tooling, mold design, and casting conditions similar to plain WCB castings were successfully used to produce sound surface alloyed butterfly castings under industrial conditions. The surface alloying was achieved by adding powders of Ni, Cr, Fe–Si, Fe–Mn, and Mo to the slurry containing a binder coated on the mold surface. The surface alloyed coatings on the surface of WCB steel butterfly valve castings were enriched in Ni, Cr, Mo, and Mn up to 6.4, 23.2, 3.3, and 1.1%, respectively. The depths of coatings were as high as 420 µm. After normalizing and tempering heat treatment, the surface alloyed layer exhibited an increase in corrosion resistance as compared to base metal WCB steel. [ABSTRACT FROM AUTHOR]

Electrostatic painting is an efficient and widespread process for coating metal parts. However, during the process, part of the powder paint is lost generating waste. Therefore, this article proposed the use of this residue as a raw material for the manufacture of floor coverings. For this, samples were made from recovered hybrid paint (THR) directly from the reuse of the painting sector of a company in the industrial painting sector and were compared with samples of virgin polyester paint (TPV) and virgin hybrid paint (THV). The samples were evaluated by means of thermal, physico-chemical, morphological and mechanical characterizations. Through the flexion test, an average flexural strength module of 28.14 MPa was obtained, which made it possible to compare the polymeric THR coating with the ceramic tiles of the Semi-Stoneware class, showing that this recycling alternative presents sufficient mechanical strength for the application. Microscopies showed residues from the factory floor interacting with the polymeric matrix of the paint resin. [ABSTRACT FROM AUTHOR]

Within the scope of this study, the practical use of ocher, which was found in the form of lumps, residues, powder and paint in archaeological sites, and the symbolic meanings attributed to them were discussed. Among the places it was found; cave fillings, tombs, temples and houses are counted. Although there have been many publications on ocher, the need for a study that includes new finds from various geographies necessitated the preparation of this publication. Thus, in the light of the available data, how the ocher started to be used, how it developed, its practical and symbolic aspects were revealed. The finds dated to about 500 thousand years ago have not been encountered since the early of the 1nd millennium BC, except for its use as a pigment. However, the connection of ocher with the present can be established through its ethnographic use. The first artistic use of this material, which has been increasingly used since the Lower Paleolithic period, can be traced back to 400 thousand years ago with its use on Tan Tan figurine. Red ocher, which is preferred at a higher rate than yellow and brown, both as a lump, powder or pigment, has shown that ocher may have been first used for symbolic purposes, primarily because it is the color of blood. However, based on the soil eating behavior seen in some animal species and humans within the scope of the study, it can be argued that it has started to be used for a pragmatic purpose. In this context, the fact that some African tribes paint themselves with an ocher-based substance to protect themselves from the sun can be interpreted as a reflection of pragmatic use. [ABSTRACT FROM AUTHOR]

In modern society, polymer‐based matte coatings have gained widespread attention for its low gloss and exquisite texture characteristics, which are capable of providing soft‐light environmental atmosphere and pleasant tactile feeling. This paper reports the definition of gloss, the measuring method, and classification of gloss, the mechanism, and method of extinction, as well as the factors that affect the gloss of films. The most significant work of this paper focuses on the research advancements in synthesis methods and matting mechanisms of ultraviolet light‐curing matte coatings, powder matte coatings and water‐based matte coatings. In general, compared with traditional polymer‐based matte coatings, a new‐developed chemical matte coating can avoid film defects caused by the addition of matting agents. Meanwhile, it can lower the raw material costs and streamline the production procedures, which are supposed to be the future development trend of matting resin industry. [ABSTRACT FROM AUTHOR]

As a result of the investigations concerning the elaboration of efficient technologies for local protection of metallic pieces with isolated coats against plasma nitriding, two variants of special paints were elaborated. Those are based on lamella copper powder with a lime magnesia binding system, in which polystyrene was added in an organic solvent. The paper analyses the advantages as a result of the usage in a mixture of magnesium oxide with carbon tetrachloride, advantages as a result of the experiments done with selected types of paints (samples subjected to ionic nitriding in a period of 15 hours at a temperature of 5300C). To check the efficiency of the protection of the elaborated paints, experiments were done comparatively on not protected metallic surfaces (steel 39MoAlCr15) and on metallic surfaces protected by protector films put in three variants of different thickness. [ABSTRACT FROM AUTHOR]

The present study aims to apply an electrostatic dry powder coating process to coat aspirin tablets with polymer blends to produce a single-layer coating film, which potentially allows an advantageous delayed sustained drug release profile. The coating formulations containing polymer blends of enteric polymer (hydroxypropyl methylcellulose phthalate or hydroxypropyl methyl cellulose acetate-succinate) and insoluble polymer (Eudragit® RL) were successfully developed and optimized. Results of scanning electron microscopy and acid resistance test demonstrated that curing conditions had a significant impact on the qualities of the produced film. Drug dissolution experiments revealed that changes in the coating level and the coating formulation with different ratios of the enteric polymer to the insoluble polymer achieved an altered and adjustable drug release profile. All of the results suggested that electrostatic powder coating technology is capable to produce a satisfactory coating film with polymer blends, allowing an advantageous functionality of delayed sustained drug release. [Display omitted] • Electrostatic dry powder coated aspirin tablets for delayed sustained release; • Programmable drug release behavior by modulating the polymer blends formulation; • In-depth evaluation of the dry coated functional coating film. [ABSTRACT FROM AUTHOR]

The corrosion propagation rate during natural exposure tests of powder-coated steel and the relationship between natural exposure and accelerated cyclic corrosion testing (ISO 20340) results were investigated. Generally, during natural exposure, an initial fast increase in the corrosion area followed by a period where the corroded area grows very slowly are observed. As a consequence, the relative ranking between coating systems varies significantly as a function of test time. Correlation between natural exposure results and cyclic test results was not found; in many cases, a better performance in one test is associated with a worst performance in the other. [ABSTRACT FROM AUTHOR]

Taking three kinds of micron aluminum powder as the research object, taking the deflagration characteristics and dynamic mechanism of aluminum dust as the main line of research, using high‐speed camera system and temperature measurement system to study the dust cloud of three kinds of aluminum powder with different concentration in the transparent pipe dust flame The flame shape, propagation speed, and temperature change law of the propagation device, the flame propagation speed and temperature increase with the increase of dust cloud concentration, and decrease with the increase of particle size; through the experiment of 20 L spherical explosive device, the empirical regression equation of maximum explosion pressure Pmax and maximum pressure rise rate (dP/dt)max is obtained, the explosion pressure (Pmax) will first increase and then decrease with the dust concentration, (dP/dt)max increases with the increase of dust concentration, while Pmax and (dP/dt)max increase with the decrease of particle size; The explosion products of aluminum powder were analyzed by XPS and surface energy spectrum, and the main substances of the explosion products were Al2O3, Al(OH)3, and unburned Al, and the deflagration mechanism model of micron aluminum powder was obtained; at the same time, the simultaneous thermal analyzer (TG‐DSC) was used to conduct microscopic thermal analysis kinetics experimental research on micron aluminum powder with different particle sizes. The combustion process of aluminum powder in the air was divided into three stages. Fit the curve by analyzing and calculate the reaction kinetic parameters of the aluminum dust combustion process. The smaller the particle size of the micron aluminum powder, the more aluminum particles involved in the oxidation reaction, the more intense the combustion reaction, the faster the flame propagation speed, the greater the height of the flame front, the greater the explosion pressure, the exothermic phenomenon is significant, and the activation energy required for the oxidation reaction to occur is smaller. [ABSTRACT FROM AUTHOR]

Powder technology has been used to coat fibers with polymeric particles to manufacture composites. The material parameters such as particle size and fiber diameter and process parameters such as the particle charge and the particle velocity will influence the powder coating process. In this work, we present an experimental setup in which we characterize the coating of micron size particles on a fiber and examine the role of process parameters on the coating density. Monodispersed Polystyrene (PS) particles (2.8 ± 0.4 μm in diameter) were used to coat a carbon fiber (CF) 7 μm in diameter. A model setup was designed and fabricated in which the PS particles were charged with an ozone charging system, while the CF was maintained at the grounded state at all times. The setup consisted of two parts namely, a cyclone and a coating chamber. The distance between the PS particles was measured and the density of coating was examined using a microscope as a function of the processing parameters used in the setup. The measured average distance between the PS particles on the CF was used in our developed numerical model to estimate the friction coefficient between the charged PS particle and the grounded CF and the fiber volume fraction. The proposed methodology can be extended to any particle size, particle charge, and fiber diameter to estimate the friction coefficient and the fiber volume fraction at the microscale level. [Display omitted] • The performance of the composite is dependent on its fiber volume fraction. • Increasing the throughput of the composite requires an understanding of the powder coating processing parameters. • Polymer charge plays an important role on dictating the final equilibrium spacing. • Predictive engineering methodology was developed to predict the friction coefficient between charged materials. [ABSTRACT FROM AUTHOR]

This study was to examine the airborne particulates/dusts and worker exposures in electro-static powder coating operations. Temporal variation and size distribution of dusts were assessed using direct-reading instrument, while the worker task-specific dust exposures (n = 41) were measured in three factories using conventional filter method. Additionally, toxic metal levels in the coating powder (n = 27) were analyzed to assess hazard potentials. Continuous monitoring of airborne respirable dust levels indicated large temporal variation across a normal working day. The particulate levels outside spraying booths were generally low (below 0.10 mg m−3) during normal spraying operation, but short-term level may reach as high as 21.8 mg m−3 (averaged at 4–5 mg m−3) when specific task such as cleaning the pipelines and spraying booth, was performed. Exploratory assessment on particle size distribution at four major working zones, administration, uploading, spraying, and baking, indicated no major difference among the zones, and between factories. The particle count median aerodynamic diameter was 0.88–1.69 µm, while the mean number concentrations were 10.97, 15.17, 18.49, and 27.03 (# cm−3) for zones administration, uploading, spraying, and baking, respectively. The worker task-specific dust exposures were found low during normal spraying, with the mean short-term total and respirable dust concentrations being 0.88 and 0.41 mg m−3, respectively. Both levels increased to 3.48 and 5.19 mg m−3, respectively (P < 0.05), if powder changing and system cleaning were done. Short-term total and respirable dust concentrations were 94.2 and 56.1 mg m−3, respectively, when complete cleaning process was performed inside spraying booth. Both levels exceeded the short-term exposure limits. The mean concentration of metals in the powder samples were 6.78, 9.52, 10 717, 2805, 1020, and 1361 µg g−1 for Pb, Cr (total), Al, Fe, Cu, and Sr, respectively. This study demonstrated that cleaning of spraying booth resulted in high dust exposures well exceeding the exposure limit. Toxic metals, particularly Pb, Cd, and Cr (total), levels measured in the powder samples were found low, and the resulting exposures were below the exposure limits, indicating relative low risks associated with the exposure at current dust levels. [ABSTRACT FROM AUTHOR]

The coated insulation layer on the surface of FeSiAl particle was prepared by an in situ generation method involving the combination of coating (utilizing a NaOH solution and NaHCO3) and high-temperature calcination for 60 min at 1250 °C. The microstructures, and magnetic and electrical properties of the coated powders, which were prepared with different concentrations of NaOH (2, 5, 10, and 15 wt%) and reaction times (10, 20, 40, and 60 min), were systematically investigated. The insulation layer of the coated powder was homogeneous and dense and contained Fe3O4, Al(OH)3, and H2SiO3 before the calcination. However, it was dominated by Al2O3 after the calcination. Al(OH)3 and H2SiO3 decomposed after the calcination into Al2O3 and SiO2 (or mixed oxide Al2SiO5), respectively, and the Al atom in the FeSiAl matrix reacted with Fe3O4 to produce Al2O3. As the NaOH concentration or reaction time increased, the layer thickness increased, and the saturation magnetic induction (Ms) and electrical resistivity (ρ) of the coated FeSiAl that had lost some Al atoms from its matrix after calcination increased significantly. The Ms and ρ of the FeSiAl powder coated with 10% NaOH for 60 min reached 161.41 emu/g and 578.6 kΩ.cm at 10 MPa pressure, respectively. [ABSTRACT FROM AUTHOR]

A new UV-curable maleimide-terminated polyimide was prepared and characterized using gel-permeation chromatography, infrared, and nuclear magnetic resonance spectroscopy. The polyimide was formulated with a commercially available UV-curable polyester resin via twin-screw extrusion to prepare a hybrid powder coating system. The hybrid powder coatings were cured by exposing the molten formulation to UV light. The films were studied by dynamic mechanical analysis (DMA), thermomechanical analysis, and differential scanning calorimetry. DMA highlighted the viscoelastic behavior of the films and showed that an increase in Tg was obtained with increasing polyimide content, as determined via the α-transition in the tanδ curve. Thermogravimetric analysis showed an improvement in the thermal stability of the polyester with the addition of the polyimide. Deformation resistance of the UV-cured films was investigated by SAOS and LAOS rheological methods to investigate the relative endurance of these coatings when subjected to different strains. The viscoelastic properties of the hybrid system were most improved when 16% weight percent of polyimide was added into the system. [ABSTRACT FROM AUTHOR]

This study aims to improve polyurethane-based coating by modified zirconium oxide and aluminum oxide nanoparticles for preparing thin polymeric heat insulation coatings. In the first step, the nanoparticles were chemically modified with the silane coupling agent. Then, three different weight percent of modified nanoparticles (1, 3, and 5% w/w) were mixed with polyurethane, to prepare the nanocomposites, which were coated on metallic plate samples. Then, these plates are used to measure the radiation heat transfer coefficients, absorption coefficient in a region of short wavelengths (UV/VIS/NIR), the emissivity coefficient, and thermography of the samples in a region of long wavelengths (IR). Results showed that by adding the modified nanoparticles to the polyurethane matrix, absorption was decreased and the emissivity coefficient was increased. According to the thermography results, it was observed that the surface temperature of both samples with 3% w/w of nanoparticles had the minimum temperature compare to others. Minimum heat surface observed for 3% w/w of modified nano zirconium oxide. [ABSTRACT FROM AUTHOR]

AlSi-polyester seal coatings and aluminum bronze/polyester seal coatings prepared by plasma spraying were used to study their reaction mechanism. The composition of AlSi-polylester and aluminum bronze/polyester powders and coatings were investigated by X-ray diffraction. The powders were analyzed by thermogravimetric differential thermal analysis and scanning electron microscopy. Comparing the powder with the coating, it is found that they have the same phase by X-ray diffraction. Thermogravimetric differential thermal analysis of the powders show that the service temperature should not exceed 500oC, otherwise the polyester constituent begins to degrade. It is also found that the aluminum bronze/polyester seal coatings have a lower porosity than the AlSi-polyester seal coatings. [ABSTRACT FROM AUTHOR]

PT. Gansa Furindo Indonesia (GFI) is a company engaged in painting and powder coating services established in 1990. In the process of making such a long and involving painting machine and labor, it does not cover the possibility of work accidents. There are 3 categories of work accidents: minor accidents, moderate accidents, and serious/major accidents. For the 3 crash categories, it is seen how severe the injuries suffered in the work accident. This study aims to determine the steps to prevent and repair work accidents after knowing the categories of work accidents that occur. This research is focused on the production department, especially in the machining area where work accidents occur due to the lack of employee awareness of Health Safety and Environment (HSE). Work accidents include crashing objects with a static state of 108 RPN, contact with the machine while moving when taking the material inside the machine is 196 RPN, short circuit of 160 RPN, reverse mounting of 90 RPN and less neat cutting in the iron cutting of 168 RPN. Therefore, improvements are made in preventing work accidents that occur by making the latest Standard Operational Procedure (SOP). [ABSTRACT FROM AUTHOR]

Corrosion is one of the biggest problems which affects the economy of the country, which occurs as a result of the interaction of the metal with its surroundings. One of the easiest ways to prevent corrosion is coatings of the metals with paint, plastic or wood. Several types of coatings have been adopted by corrosion scientists in the prevention of corrosion that are mainly based on electrochemical principles. Fortunately, based on cost and effectiveness, four types of coatings are variably employed by the metal and metallurgy industries. One among the cheapest and effective way to prevent corrosion is to use barrier coatings like plastic, powder and paint. Hence, nanocomposite coatings by electrochemical deposition offers an excellent, scratch and corrosion resistance on the metal surface. These coatings may be used to restoration of the components instead of interchanging them, resulting in reduced maintenance costs and disturbance. Significant improvements in the corrosion protection of steel have been reported by using metal-metal matrix, metal-metal oxide matrix, metal-polymer matrix, and ceramic-metal matrix nanocomposite. This review presents an overview of works related to nanocomposite coatings and to re-evaluate the literature for the future research in the field that still lacks validation. [ABSTRACT FROM AUTHOR]