MDF定制家居粉末涂料目前的研究空白或挑战以及未来发展趋势

In this study, we investigate a novel post-processing approach combining heat annealing and powder coating to enhance both the mechanical performance and surface finish of polylactic acid (PLA) 3D-printed components. Previous work demonstrated that annealing PLA at temperatures between 100 and 120 °C significantly improves its mechanical properties. Building on this, we explore the effects of applying medium-density fiberboard (MDF) powder coating, which cures at a similar temperature range, to simultaneously improve the material’s surface aesthetics. Test specimens were printed with identical parameters and subjected to heat treatment at 120 °C for varying durations (0 to 15 min, in one-minute intervals). Additional observations included dimensional stability and surface uniformity. The results indicate a clear correlation between post-processing time and improvements in both strength and surface appearance, with optimal outcomes observed between 5 and 8 min of curing. This combined post-processing method provides a cost-effective and accessible way to enhance part performance and aesthetics, thereby expanding the applications of PLA-based additive manufacturing, particularly in functional and design-focused use cases.

An Intelligent Digital Twin (IDT) was created to analyze 3D-CAD models for optimizing individual production plans in the context of powder coating. The IDT performs a kinematic simulation of the workpieces in preparation for the subsequent real production. We utilized the novel concept of analyzing CAD files directly in a game engine after an automatic runtime import. This runtime import of 3D-CAD models into game engines is a unique feature that addresses a research gap with significant reuse potential in other applications. This approach is necessary because of the custom shapes of the workpieces, which undergo feature detection, virtual assembly, and optimization by simulation. This leads to a fast and early calculation of production costs, thereby enhancing the competitiveness of the company. The IDT is fully automated and is available 24/7 to plan production immediately after receiving a 3D-CAD file, thereby boosting production planning.

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Conventional colorimetric evaluation methods remain inadequate for accurately characterizing scrub-induced color changes on UV-printed and water transfer-printed decorative coatings applied to MDF after chemical resistance testing; therefore, this study proposes an image-based colorimetric characterization approach using an Image Processing-Based Scrub Tester to quantitatively assess such changes under simulated domestic chemical exposure. For this study, 8 mm thick Medium-Density Fiberboard sheets with a bright white, polyvinyl chloride-coated Medium-Density Fiberboard, high-gloss acrylic coating Medium-Density Fiberboard, Medium-Density Fiberboard lam, and Medium-Density Fiberboard sheets treated with polyurethane, cellulose-based, water-based and acrylic paints were utilized. A carbon fiber-patterned organic finish was applied to the surfaces of the pre-treated Medium-Density Fiberboard sample using ultraviolet printing and water transfer printing (WTP) techniques, followed by scrubbing testing with various domestic cleaning agents in compliance with Turkish Standards. As part of the picture evaluation process in this study, digital picture of the samples was captured after and before the scrubbing process. Color measurements were then analyzed based on L*, a*, and b* coordinates, conforming to the Commission Internationale de l'Éclairage (CIE L*a*b*) color system, utilizing a newly developed evaluation technique. From the outcomes of the study, it was observed that the overall color shift of the water transfer printing samples was 124,63% more than the ultraviolet printed samples. To assess the precision of the Image Processing-Based Scrub Tester's color measurement system developed in this research, its results were benchmarked against those from a different color tester. As a result, the findings strongly suggest that the color test analysis performed with Image Processing-Based Scrub Tester, together with the developed software, has the potential to serve as an alternative to industrial testing equipment.

The aim of this study was to determine the effects of hygiene (H) and nano-color pigment (NCP) modifications on hardness, glossiness, and adhesion strength of some surface coating materials produced specifically for use in wooden toys. For this purpose, H- and NCP-modified polyurethane (PU) and waterborne (WBV) varnishes were applied to specimens prepared from Oriental beech (Fagus orientalis L.) and Oriental plane (Platanus orientalis L.) woods; Oriental beech, birch (Betula pendula), and poplar (Populus deltoides) plywood; and medium-density fiberboard (MDF). Then, hardness, glossiness, and adhesion values were determined. Results indicated that the highest values were obtained for hardness in PU and PU*NCP applied to MDF; for glossiness in WBV*H applied to birch plywood and MDF; and for adhesion strength in WBV and PU*H applied to beech. H and NCP modifications have significant effects on hardness, glossiness, and adhesion strength. As a result, it was determined that hardness and glossiness increased with H modification and decreased with NCP, especially glossiness. Furthermore, it was determined that H and NCP decreased the adhesion strength. Future studies comparing natural antibacterial effects of different wood species with various coating types will contribute to the development of products that are safe for children and sustainable.

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This study investigates the influence of various tool coatings, cutting speeds, and feed per tooth values on cutting forces during the CNC milling of Medium Density Fiberboard (MDF). The coatings tested include reference, TripleSi, Hyperlox, DLC, and lapped coatings. Experiments were conducted using an SCM Morbidelli m100 CNC milling machine under controlled conditions. Cutting speeds were set at 8, 10, and 12 m/s, while feed per tooth values were varied at 0.1, 0.2, and 0.3 mm. Cutting forces were measured using a three-axis piezoelectric dynamometer Kistler, and the data were analyzed to determine the impact of these variables on cutting performance. The results revealed that while cutting speed had a minimal effect on cutting forces, feed per tooth significantly influenced them, with higher values of feed per tooth leading to increased forces. Among the coatings, lapped and TripleSi exhibited the lowest cutting forces, whereas DLC showed the highest. Statistical analysis, including ANOVA and Scheffé tests, confirmed the significant differences between the coatings and highlighted the superior performance of the lapped and TripleSi coatings in reducing cutting forces.

An Image Processing Based Scrub Tester (IPBST) was used to imitate the effect of household chemicals on furniture and decoration elements. For this purpose, 8 mm-thick, bright white, acrylic coated medium density fiberboard (MDF), polyvinyl chloride coated MDF, MDF lam ready-to-use sheets, and cellulosic, polyurethane, acrylic, and water-based paint applied MDF sheets were used. Carbon fiber patterned decorative coating was applied to the prepared sample surfaces using the water transfer printing and ultraviolet printing methods. The surfaces of the samples were scrubbed with various household chemicals in accordance with the Turkish Standard TS EN ISO 11998. In the image processing phase, the images before and after scrubbing were first converted to hue, saturation, and value color space. The relationship between the abrasion measurement method of the proposed IPBST and the abrasion data obtained from the stereo microscope device was examined using the Pearson Correlation analysis. The relationship between both abrasion test methods was positive, very strong, and significant (0.81). Thus, the IPBST can be used as an alternative to industrial test devices as it obtains similar data.

The aim of this study was to determine the usability of selected natural dye extracts as environmentally friendly colorants that are used in painting of MDF based furniture and evaluate their resistance to scratch resistance, adhesion resistance, and surface hardness properties. In this study, the water-based lacquer coatings were prepared with natural dyes obtained from purple cabbage ( Brassica oleracea ), safflower ( Carthamus tinctorius ), Red beetroot ( Beta vulgaris ) and three synthetic paints that were black, blue and light blue as a comparison. Coated MDF test panels used for evaluation of performances of dyes to abiotic factors that are determined by mechanical tests such as scratch resistance, adhesion resistance, and surface hardness. As a result of the study, it has been observed that, except for scratch resistance, natural dyes perform as well as synthetic ones as alternative colorants in the lacquer coatings. Thus, natural and aesthetic raw materials that are environmentally friendly dyes can be used safely especially in children’s furniture and for wood-based products that are especially used indoors.

This work focused on obtaining a low-temperature powder coating characterized by self-healing properties. To achieve this, acrylic resin, blocked polyisocyanates (bPICs) with 1,2,4-triazole, and unsaturated commercial resin were used. The synthesis of bPICs with triazole enabled the low-temperature curing and reversible Diels–Alder (DA) reaction at 160 °C. The chemical structure of bPICs was confirmed using 1H-NMR. The occurrence of the DA and retro-DA (rDA) reactions in the crosslinked polymer, at temperatures of 60–85 °C and 90–130 °C, respectively, was confirmed using Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), and FT-IR spectroscopy. The self-healing properties of the powder coating were examined using polarized optical microscopy. Additionally, the occurrence of the DA and rDA reactions between triazole and unsaturated polyester resin was investigated through repeated self-healing tests.

Developing effective latent curing agent for rapid curing of epoxy resins at low temperatures remains challenging. This study reports a latent curing agent, ortho‐cresol phenolic epoxy resin‐bisphenol A (EOCN‐BPA), prepared through the addition reaction of o‐methyl phenolic epoxy resin with BPA. When blended with dicyandiamide (DICY) in a 1:3 molar ratio, EOCN‐BPA/DICY is used to cure a linear epoxy phenolic novolac (EPN) resin (epoxy equivalent: 550 g eq−1, softening point: approximately 82°C), at an onset curing temperature of 90°C, which is considerably lower than the onset curing temperature of DICY with EPN (160°C). However, EOCN‐BPA does not react with EPN without a catalyst. Therefore, this latent curing system is successfully applied in powder coatings, rapid curing at 120°C within 3 min without an additional catalyst, outperforming the EPN/EOCN‐BPA system using cocatalyst 2‐methylimidazole. Consequently, DICY catalyzes the curing reaction between the phenol hydroxyl group and epoxy resin and participates in it. The prepared powder coating exhibits excellent storage stability, maintaining its properties for over 3 months at room temperature. These findings demonstrate the excellent latent properties of EOCN‐BPA/DICY, highlighting its potential as a highly effective latent curing agent.

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In this study, a rubber-composite-nanoparticle-modified epoxy powder composite coating with low curing temperature and high toughness was successfully fabricated. The effects of N,N-dimethylhexadecylamine (DMA) carboxy-terminated nitrile rubber (CNBR) composite nanoparticles on the microstructure, curing behavior, and mechanical properties of epoxy-powder coating were systematically investigated. SEM and TEM analysis revealed a uniform dispersion of DMA-CNBR in the epoxy-powder coating, with average diameter of 100 nm. The curing temperature of the epoxy-composite coatings had reduced almost 19.1% with the addition of 1phr DMA-4CNBR into the coating. Impact strength tests confirmed that DMA-CNBR-modified epoxy-composite coatings showed significant improvements compared with the neat EP coating, which was potentially attributed to the nanoscale dispersion of DMA-CNBR particles in epoxy coatings and their role in triggering microcracks. Other mechanical properties, including adhesion and cupping values, were improved in the same manner. In addition, thermal and surface properties were also studied. The prepared epoxy composite powder coating with the combination of low curing temperature and high toughness broadened the application range of the epoxy coatings.

A series of small molecule urethane methacrylates were synthesized and used as reactive diluents for UV-curable polyester powder coatings. A UV-curable polyester oligomer was prepared and formulated with the reactive diluents and a photoinitiator package. Kinetics studies were carried out using photo-differential scanning calorimetry (photo-DSC). The influence that the reactive diluent concentration, UV-light intensity, temperature, and atmosphere had on the reaction kinetics was investigated. Crosslinked samples that were analyzed via DSC showed that the glass transition temperature correlated well with the extent of conversion. In general, lower curing temperatures (i.e., ≤ 80°C) significantly reduced the conversion and polymerization rate. However, the use of a mono-functional reactive diluent facilitated much higher conversions than the UV-curable polyester control, even at just 5 wt% loading level. These findings suggest that reactive diluents can be used to improve the low temperature cure capability of UV-curable polyester powder coatings.

Abstract Glutaraldehyde has recently drawn attention as a crosslinking agent for PVA due to its ability to facilitate reactions under ambient conditions. The study focused on comparing the effects of glutaraldehyde, formaldehyde, and glyoxal as crosslinking agents for PVA under similar conditions, using different aldehyde-to-PVA ratios (0.2, 0.4, 0.6, 0.8, and 1.0). The crosslinking reaction was conducted at 50 °C for a duration of 5 min, to assess the efficiency of crosslinking agents at milder conditions. Initial evaluations focused on determining the water swelling degree, the degree of crosslinking, and moisture uptake of the prepared films under humid conditions. Results demonstrated a high degree of crosslinking: with glutaraldehyde at GA/PVA ratios of 0.6 and 0.8, crosslinking reached 99%. Formaldehyde achieved a crosslinking degree of 97% at an FA/PVA ratio of 0.8, while glyoxal reached 90% at a ratio of 0.2. Among the aldehydes tested, glutaraldehyde exhibited the highest crosslinking efficiency under similar conditions, making it the preferred crosslinker for further characterization studies. FTIR, TGA, and XRD spectra confirmed successful crosslinking between GA and PVA, evidenced by acetal bond formation and changes in the diffraction patterns correlating with increased amorphous character in the PVA films.

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The level of wood consumption is important in particleboard (PB) manufacturing because wood is a natural source. This study aimed to determine the optimum wood consumption in PB manufacture. The study examined how the PB’s surface (SL) and core (CL) layer ratio and sanding tolerance affect the PB surface laminating condition. The optimal manufacturing conditions were determined among different combinations of PB density (520 or 560 kg/m3), SL/CL ratio, and sanding thickness using the multi-criteria decision-making method (MCDM). Grey relational analysis (GRA) was used as MCDM. Samples were characterized according to TS EN 312. The moisture content (MC) increased (30%) as the SL ratio increased. Thickness swelling (TS) and water absorption (WA) generally decreased as SL increased. Increasing surface layer density and board density significantly improved internal bond (IB) strength and surface stiffness (SS). Modulus of rupture (MOR) and elasticity (MOE) decreased as the sanding tolerance increased. Surface and edge screw withdrawal (SRy and SRk) resistance were increased as the density, sanding tolerance, and surface density increased. This study is the first comprehensive optimization approach to improve quality in coating low-density particle boards with decorative paper, potentially leading to material savings and production efficiency for the furniture and coating industries.

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The particle size of powder coatings is an important factor affecting flow and fluidization performance, which in turn determines the quality of the coating. Powder coating particles, such as boron nitride, titanium dioxide, barium titanate, niobium oxide, and tungsten oxide, can be seen in SEM images as circular or polygonal shapes, with irregular edges and sizes, as well as aggregation and stacking between them. This paper introduces a novel method of automatic particle identification and size analysis applied in SEM images for the investigation of coating quality. Firstly, a fast gradient segmentation algorithm (Split–Merge) is utilized to automatically generate samples through determining the adhesive particles and particle groups. The samples are then manually checked and corrected to further segment the particles in order to form the dataset. Finally, the YOLOv5, a mature target detection algorithm, is used to train the labeled data in order to produce a multi-target detection recognition model. The model can be applied to identify more pictures of the same substance, and the particles’ long and short axes are estimated using the elliptical coverage of the particles within the identified image boundary box. Experiment results from four kinds of powders suggest that this method can provide automatic particle size analysis for industrial SEM particle images.

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Modified chrysotile fiber can be used as a filler in the epoxy-polyester powder composition to improve its physicochemical properties and obtain a thermosettable polymer coating with improved properties. Purpose: The aim of this work is to study the chemical composition of the initial and fiber-modified chrysotile powder composition and evaluate physicochemical properties of polymer coatings. Research findings: It is shown that the chemical composition of the initial powder composition changes after the addition of modified chrysotile fiber. The salt and acid resistance of the obtained polymer coatings increases. The porosity of coatings filled with fibers decreases in comparison with unfilled ones. The heat resistance of the obtained polymer coating with the addition of modified fibrous fillers grows at heating at 190 and 550 °C.

Abstract In the production of powder-coating polyester, a strong odor emanates from the water, prompting us to investigate its composition and origin. We studied the process of powder coating epoxy/polyester 50/50, which employs butyl tin tris (2-ethyl hexanoate) as a catalyst. The esterified water was extracted using ethyl acetate. It was analyzed via GC–MS to identify the side reactions and by-products that arise during the tin-catalyzed esterification process. Then we discussed their formation mechanism. Our results indicate that butyl tin tris (2-ethyl hexanoate) triggers side reactions such as cyclization and transesterification, leading to the production of by-products such as heterocyclic compounds (1,4-dioxane), anhydride compounds (propionic anhydride), and others. Notably, the unpleasant odor was found to be derived from propionic anhydride. These findings provide insights into the chemistry of tin-catalyzed esterification and highlight the importance of addressing the formation of unwanted by-products in the production of powder-coating polyester.

This paper presents the results of a study of the qualitative parameters of the coating of the polymer-powder composition of coniferous wood, depending on the modes of heat treatment during its production. The quality of the polymer coating was assessed by abrasion, lattice incision and pencil hardness methods. To obtain coatings, an epoxy-polyester composition applied to wood by spraying followed by curing during heat treatment was used. The temperature of the heat treatment varied in the range of 80-120 ° C with an exposure time of 5-20 minutes. The intervals of thermal effects were chosen based on the analysis of domestic and international research experience in this area. The influence of the curing time and temperature of the polymer-powder coating on the following parameters of the material surface is shown: wear resistance, water absorption, adhesion, hardness. It was found that the wood coating based on an epoxy-polyester powder composition, treated at a temperature of 90 ° C for 15 minutes, has the highest quality technological and operational parameters. An increase in temperature and processing time has a negative effect on the quality of the coating due to the release of resins from the wood. This is especially noticeable at a curing temperature of 120 °C, when the process of resin extraction from coniferous wood increases. The results obtained make it possible to optimize the process of processing wood using polymer-powder coatings to achieve maximum protection and decorative characteristics with simultaneous drying or thermal exposure. Based on a comparative analysis with the literature data, it is shown that the technological modes of processing polymer powder paint significantly depend on the type of wood.

Powder coatings are a promising, solvent-free alternative to traditional liquid coatings due to the superior corrosion protection they provide. This study investigates the effects of incorporating montmorillonite-based nanoclay additives with different particle sizes into polyester/triglycidyl isocyanurate (polyester/TGIC) powder coatings. The objective is to enhance the corrosion-protective function of the coatings while addressing the limitations of commonly employed epoxy-based coating systems that exhibit inferior UV resistance. The anti-corrosive and surface qualities of the coatings were evaluated via neutral salt spray tests, electrochemical measurements, and surface analytical techniques. Results show that the nanoclay with a larger particle size of 18.38 µm (D50, V) exhibits a better barrier effect at a lower dosage of 4%, while a high dosage leads to severe defects in the coating film. Interestingly, the coating capacitance is found, via electrochemical impedance spectroscopy, to decrease during the immersion test, indicating a self-repairing capability of the nanoclay, arising from its swelling and expansion. Neutral salt spray tests suggest an optimal nanoclay dosage of 2%, with the smaller particle size (8.64 µm, D50, V) nanoclay providing protection for 1.5 times as many salt spray hours as the nanoclay with a larger particle size. Overall, incorporating montmorillonite-based nanoclay additives is suggested to be a cost-effective approach for significantly enhancing the anti-corrosive function of powder coatings, expanding their application to outdoor environments.

In this paper, a method to characterize the hiding power of powder coating by dispersing powder coatings in various dispersants and brushing obtained suspension coating was studied. When colorless, transparent and low-viscosity reagents reagent, containing epoxy functional group, is used as the dispersant of TGIC polyester thermosetting powder coating, the hiding power of this kind of powder coating can be accurately determined. When the dispersion concentration of powder coating is in an appropriate range (mass fraction 32%-45%), the hiding power has nothing to do with the concentration, and the test results reflect the properties of powder coating itself.

Polyacrylic resins containing glycidyl methacrylate (GMA), methyl methacrylate (MMA) and n-butyl acrylate (BA) in various molar ratios were obtained. Triaryl sulfonium hexafluorophosphate was used as a photoinitiator and reacted with the epoxy groups of GMA. The relationship between the chemical structure of polyacrylic resins and the parameters of the UV curing reaction and the functional properties of powder coatings was investigated. The appearance and mechanical properties of the coatings were determined based on thickness, gloss, roughness, deformability, scratch resistance, adhesion to steel, hardness, and water contact angle. DMA was used to assess the cross-link density. Powder coatings with good physical and mechanical properties and curing time of 70 s were obtained.

Methods for the synthesis of urethane acrylates used as new crosslinking agents for hydrophobic UV-curable powder clear coatings were developed. In the synthesis of urethane acrylates, isophorone diisocyanate, glycerin, xylitol, polyethylene glycol and polysiloxane KF-6000, as well as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, were used. In order to increase the functionality of urethane acrylates, glycerin and xylitol derived from renewable sources were introduced. The chemical structure of the urethane acrylates was verified by IR spectroscopy. UV-curable powder clear coatings were obtained through a combination of urethane acrylates with unsaturated polyester resins. The thermal behavior and crosslinking density were examined using DMA. The obtained coatings were evaluated by performing the following tests: roughness, gloss, scratch resistance, hardness, adhesion to steel and water contact angle. As part of this research, high hydrophobicity and scratch resistance of UV-curable powder clear coatings were developed, which are a VOC-free and economically attractive alternative method for low thermal resistance surface protection, such as for composites, wood and wood-based materials.

BACKGROUND Polyesters are applied in high-end products in many industrial applications, including resins and powder-coating applications. The characterization of the chemical heterogeneities within a polyester is of utmost interest to develop new products or improve existing applications. Unfortunately, characterization is a difficult task, as polyesters may feature distributions in end-group functionality, molecular weight, chemical composition, and degree of branching. Currently, no analytical method can characterize all these interdependent distributions in a single analysis. RESULTS We report the use of comprehensive normal-phase liquid chromatography × size-exclusion chromatography hyphenated with ultraviolet-light spectroscopy and high-resolution mass spectrometry in parallel (NPLC × SEC-UV/HRMS) to characterize polyesters according to their end-group-functionality and molecular-weight distributions. The chemical composition can be measured with HRMS, while relative quantitation can be performed with UV detection. A supercharging agent was used during ionization allowing to extend the molecular-weight range of the detected chemical species. SIGNIFICANCE The presented platform allows characterization of polyesters with varying fractions of carboxyl or hydroxyl end-group functionalities and varying distributions of molecular weight, degree of branching, and chemical compositions. The number-average and weight-average molar masses are obtained in the same analysis. This information cannot be obtained by any one-dimensional technique. The developed NPLC × SEC-UV/HRMS platform is a valuable tool for characterizing polyesters in an industrial setting.

In this work, low-zinc epoxy powder coating primers with anticorrosive properties were developed. For this purpose, single-walled carbon nanotubes (SWCNTs) were introduced into powder coatings. The obtained coatings were evaluated by performing the following tests: adhesion to steel, roughness, gloss, color, water contact angle, salt spray, electrochemical impendance spectroscopy (EIS), and transmission scanning microscopy (TEM). The anticorrosion resistance of the powder coating primers obtained depends on the zinc and SWCNT content, as well as the degree of dispersion in the paint. The mechanism of anticorrosion activity was proposed.

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This paper addresses the topic of quality assessment and defect analysis in powder coating processes applied to metal structures, particularly galvanized steel. Powder coating is a widely adopted surface finishing technique used to enhance the protection and aesthetics of metal products, especially in the construction and manufacturing sectors. The study focuses on evaluating the quality of paint coatings produced in the powder coating process and analyzing the causes of defects. Research was conducted on products from several powder coating plants across different regions, mainly manufacturing galvanized steel structures, including fencing systems. Quality assessment involved visual inspection, optical and scanning electron microscopy, chemical composition analysis, corrosion resistance testing, and adhesion tests. To determine defect causes, quality management tools such as the Ishikawa diagram and the 5 Whys method were applied. The results identified common imperfections like poor adhesion, surface contamination, and coating porosity. These were primarily linked to improper surface preparation and process control. Based on the findings, specific recommendations were proposed to reduce the occurrence of defects and improve the overall coating quality. The study contributes to enhancing process reliability and product durability in the powder coating industry.

The wear tests of a powder coating with modifying additives of corundum were carried out at low climatic temperatures. Data on the mass wear of the coating and the corresponding counterbody made of steel ШХ15 (Russian name) was obtained, and the characteristics of the friction surface profile of the coating were studied. The structural state of the friction surface before and after wear tests was investigated by X-ray diffraction analysis.

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ABSTRACT The UV-curable inkjet coating system on the surface of wood-based substrates consists of the substrate, primer, printing layer, and topcoat layer. To enhance the compatibility at the interface between the UV-curable primer and the inkjet coating on the substrate surface, this study employed air plasma to modify the medium-density fiberboard substrate's primer surface under varying treatment power and speeds. By analyzing the changes in contact angle, chemical composition, and elemental composition of the substrate primer surface under different plasma treatment conditions, theoretical support was provided for the improvement of the bonding between the UV-curable primer and the printing layer. The results show that with a plasma treatment speed of 0.4 m/min and power of 700 W, the contact angle with water on the surface was 20°, and the whiteness value was 80.5 Wb. The C = C bonds on the primer surface break and combine with oxygen elements to form oxygen-containing functional groups or peroxides, increasing the surface polarity and activity of the primer. When the plasma treatment power was 750 W and the speed was 0.8 m/min, the relative concentration of oxygen elements on the UV-curable primer surface increased to 49%, while the carbon element content decreases by 29%.

The structural properties and whiteness of the substrate surface markedly effect printing quality and are closely related to the primer coating processes. Herein, four different roller coating schemes were applied on MDF surfaces to change their structural properties and color, and the whiteness, gloss, and roughness properties of the substrate surfaces were characterized for UV inkjet printing. Data analysis was conducted to explore the effects of these variables on the color reproduction, relative contrast, and printing gloss of the MDF substrates. The results showed that, according to CMYK, L*a*b* values and spectral reflectance data, the finishing of the MDF substrate with a 40 g/m2 layer of transparent primer combined with three layers of white primer at 20 g/m2 per roll coating layer had the best color reproduction effect for UV inkjet printing. Regarding the effects of relative contrast, the correlation with whiteness and glossiness was significant, while the correlation with glossiness was minor. The inkjet printing gloss value was positively correlated with substrate primer surface whiteness, while it was negatively correlated with roughness. When the surface whiteness of the substrate was relatively high, the roughness was lower and the printing effects were glossier. We sought to optimize the printing effects of all aspects of the MDF substrate by primer coating. The results of this work provide a feasible application method to improve printing quality and enhance the added value of low-quality boards, as well as to further expand the application of UV inkjet printing in the wood decoration market.

No matter where we reside, the issue of greenhouse gas emissions impacts us all. Their influence has a disastrous effect on the earth’s climate, producing global warming and many other irreversible environmental impacts, even though it is occasionally invisible to the independent eye. Phase change materials (PCMs) can store and release heat when it is abundant during the day (e.g., from solar radiation), for use at night, or on chilly days when buildings need to be heated. As a consequence, buildings use less energy to heat and cool, which lowers greenhouse gas emissions. Consequently, research on thermally active medium-density fiberboard (MDF) with PCMs is presented in this work. MDF is useful for interior design and furniture manufacturing. The boards were created using pine (Pinus sylvestris L.) and spruce (Picea abies L.) fibers, urea–formaldehyde resin, and PCM powder, with a phase transition temperature of 22 °C, a density of 785 kg m−3, a latent heat capacity of 160 kJ kg−1, a volumetric heat capacity of 126 MJ m−3, a specific heat capacity of 2.2 kJ kgK−1, a thermal conductivity of 0.18 W mK−1, and a maximum operating temperature of 200 °C. Before resination, the wood fibers were divided into two outer layers (16%) and an interior layer (68% by weight). Throughout the resination process, the PCM particles were solely integrated into the inner layer fibers. The mats were created by hand. A hydraulic press (AKE, Mariannelund, Sweden) was used to press the boards, and its operating parameters were 180 °C, 20 s/mm of nominal thickness, and 2.5 MPa for the maximum unit pressing pressure. Five variants of MDF with a PCM additive were developed: 0%, 5%, 10%, 30%, and 50%. According to the study, scores at the MOR, MOE, IB, and screw withdrawal resistance (SWR) tests decreased when PCM content was added, for example, MOE from 3176 to 1057 N mm−2, MOR from 41.2 to 11.5 N mm−2, and IB from 0.78 to 0.27 N mm−2. However, the results of the thickness swelling and water absorption tests indicate that the PCM particles do not exhibit a substantial capacity to absorb water, retaining the dimensional stability of the MDF boards. The thickness swelling positively decreased with the PCM content increase from 15.1 to 7.38% after 24 h of soaking. The panel’s thermal characteristics improved with the increasing PCM concentration, according to the data. The density profiles of all the variations under consideration had a somewhat U-shaped appearance; however, the version with a 50% PCM content had a flatter form and no obvious layer compaction on the panel surface. Therefore, certain mechanical and physical characteristics of the manufactured panels can be enhanced by a well-chosen PCM addition.

In this work, silver-free, low-temperature-curing epoxy powder coatings with antimicrobial functionality were developed. The cationic biopolymer ε-polylysine (PLY) in its protonated form, as well as its intercalation and co-intercalation products with aminododecanoic acid (ADA) in montmorillonite (MMT), were employed as environmentally friendly bioactive additives. The powder coatings were formulated using epoxy resin and a highly reactive phenolic curing agent and subsequently applied onto steel substrates. The resulting materials were comprehensively characterized in terms of surface morphology, gloss, hardness, adhesion, and wettability. The coating showed a water contact angle of approximately 85°and an antibacterial reduction exceeding 99% against E. coli and S. aureus under laboratory conditions (ISO 22196). Antimicrobial activity is most likely associated with electrostatic interaction between the cationic PLY and bacterial membranes. Overall, this study suggests a promising and sustainable, silver-free strategy for developing antimicrobial powder coatings that may be suitable for hygiene sensitive environments, pending further long-term and safety evaluation.

Powder coatings, due to the lack of solvents and volatile organic compounds (VOCs), have gained in importance compared to conventional liquid systems. They fulfill key criteria such as effectiveness, economics, energy efficiency, environmental compliance, and excellent surface finish. Recently, low curing temperature and UV-cured systems have been increasingly used. These techniques offer a lot of advantages such as, application of powder coatings on the heat-sensitive materials and energy savings. Acrylic resins are rarely used in powder systems, mainly due to their price. Nevertheless, they are an attractive alternative in low temperature curing or UV-cured systems (free radical or cationic polymerization) thanks to their chemical structure. The review article focuses on the correlation between the chemical structure of the corresponding monomers in the resin and their properties and application in powder coatings. Moreover, the correlation between the structure of acrylic resin and the powder coating formulation process was described.

This paper presents studies on the influence of the chemical structure of (meth)acrylic monomers on the properties of powder coatings based on polyacrylate resins. For this purpose, a wide range of monomers were selected—2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA), n-butyl acrylate (nBA), tert-butyl acrylate (tBA), dodecyl acrylate (DA), ethyl acrylate (EA) and benzyl acrylate (BAZ)—for the synthesis of the polyacrylate resin. The average molecular mass and molecular mass distribution of the synthesized resins were measured by gel permeation chromatography (GPC). The glass transition temperature (Tg) and viscosity of polyacrylate resins were determined by using differential scanning calorimetry (DSC) and a Brookfield viscometer. These parameters were necessary to obtain information about storage stability and behavior during the application of powder clear coatings. Additionally, DSC was also used to checked the course of the low-temperature curing reaction between the hydroxyl group contained in the polyacrylate resin and the blocked polyisocyanate group derived from a commercial agent such as Vestanat B 1358/100. The properties of the cured powder clear coatings were tested, such as: roughness, gloss, adhesion to the steel surface, hardness, cupping, scratch resistance, impact resistance and water contact angle. The best powder clear coating based on the polyacrylate resin L_HEMA/6MMA/0.5nBA/0.5DA was characterized as having good scratch resistance (550 g) and adhesion to the steel surface, a high water contact angle (93.53 deg.) and excellent cupping (13.38 mm). Moreover, its crosslinking density (CD) and its thermal stability was checked by using dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA).

This study aimed to assess the impact of surface geometry, preparation, and coating procedures on the corrosion behavior of HAA-polyester powder coated steel components in a salt spray test. The coating process of the steel parts involved degreasing, Zn spray coating, an epoxy powder primer, and a polyester powder topcoat. Results highlighted the crucial role of surface geometry, with flat surfaces showing superior corrosion resistance compared to welded joints, sharp edges, or hollow cylinders. For standard flat panels, no red rust was observed for over 600 hours in the salt chamber, meeting ISO 12944-6 requirements. However, non-standard panels with complex geometries showed rust much earlier, particularly after 108 hours in welded zones and sharp corners when an epoxy primer was not used. Applying the primer extended corrosion resistance by 2-3 times. Hollow cylinders developed rust after 240 hours due to insufficient coating thickness inside the cylinders. Crevices remained vulnerable, as the coating did not reach inner parts. Applying powder to individual components before assembly, and using brush painting on critical areas, such as welded joints and sharp corners, are strongly suggested to improve protection. Additionally, the evaluated polyester powder coatings exhibited outstanding mechanical strength and camouflage capabilities, making them highly suitable for military applications.

Magnesium alloys, because of their excellent strength-to-weight ratio, are increasingly used in many industries. When used in external elements, the key factor is to provide adequate anticorrosion protection. High-temperature, cured-powder coatings are widely used to protect most metals, but their use on magnesium alloys is difficult as a result of the instability of the magnesium substrate at elevated temperatures. Another problem is ensuring the proper adhesion of the organic coating to the magnesium substrate. This paper presents the procedure for the synthesis of a duplex coating on AZ91 magnesium alloy. The topcoat was a powder coating based on acrylic resin, the main ingredient of which was glycidyl methacrylate. Because of the presence of epoxy groups, the coating was cured using ultraviolet (UV) radiation (low-temperature technology). The conversion subcoating was produced by plasma electrolytic oxidation (PEO) in an alkaline silicate electrolyte. The synthesized coating system was tested, among others, for microscopic (SEM), adhesive (mesh of cuts), and anticorrosion (EIS). The duplex PEO/UV-curable powder coating showed very good adhesion to the metal and increased the anticorrosion properties of the magnesium substrate, compared to the powder coating produced directly on the magnesium alloy and on an alternative conversion coating (synthesized in the process of chemical zircon phosphating).

This work investigates the formulation of a radiation-curable coating that integrates functionalized carbon nanotubes (f-CNT) to improve surface characteristics. Trimethylolpropane triacrylate (TMPTA) was employed as the monomer, with epoxy acrylate and urethane acrylate as oligomers and Irgacure-500 as the photoinitiator. To cure the coatings, the formulations were subjected to ultraviolet (UV) light, and the surface properties were investigated using Fourier-transform infrared spectroscopy (FTIR), pendulum hardness testing, and thermogravimetric analysis (TGA). The results show that altering the ratios of f-CNT in the formulations have a considerable impact on the mechanical and thermal characteristics of the coating. The findings show that ideal compositions of these additives improve the hardness, crosslinking density, and thermal stability of the cured films, offering insight into their potential

Conventional alkyd resins are widely used for their durability and gloss, but often rely on organic solvents that release harmful volatile organic compounds. In this study, a bio‐based content exceeding 50% ultraviolet (UV)‐curable alkyd resin was synthesized via a solvent‐free, enzyme‐catalyzed process to improve the performance of environmentally friendly coatings. Monoglycerides, glycidyl methacrylate, itaconic anhydride, phthalic anhydride, and succinic anhydride were employed as comonomers to systematically investigate the influence of different anhydride ratios on the properties of the cured films. The results demonstrated that increasing the succinic anhydride content significantly enhanced the flexibility of the films (from 15 to 3 mm), improved adhesion (from grade 3B to 4B), and elevated impact resistance (from 20 to 50 cm). The incorporation of flexible aliphatic segments from succinic anhydride not only improved the film‐forming properties but also enhanced adhesion to hydrophilic substrates. These findings offer valuable theoretical and practical insights for the formulation and application of UV‐curable alkyd resins in advanced functional coatings.

In this study, a hydrophobic, wear-resistant ultraviolet (UV)-curable coating was investigated as an alternative to traditional coatings with low hardness and high susceptibility to scratching. The SiO2 nanoparticles were ground and modified using high-energy ball milling, during which the surface energy of nano-SiO2 particles rapidly increased as their particle size decreased. Different proportions of modified nano-SiO2 particles were added to the coating and cured into a film. The structure of the composite coating was analyzed via infrared spectroscopy, scanning electron microscopy, and X-ray diffraction, which confirmed the successful preparation of the composite coating. The mechanical and optical property tests of the coating were investigated. With a 5% nano-SiO2 content, the hardness of the coating reached 5H, whereas the adhesion was poor (2B), and the flexibility was 1. The overall comprehensive performance of the coating was best when the addition amount was 3%. The coating exhibited good hardness, flexibility, and adhesion. The hardness of the coating reached 4H, the adhesion was 4B, the flexibility was 5, the coating haze was 12.38 HZ, and the contact angle was 118°.

Ultraviolet (UV)-curable coatings were prepared using rosin-based polyurethane as an oligomer with different active diluents and crosslinking monomers. The effects of different components level on the properties of the polyurethane coatings were investigated, and the effects of the mass ratio of the active diluents, crosslinking monomers, adhesion promoting monomers, photoinitiators, and curing times on the polyurethane coatings were discussed. The results showed that when hydroxypropyl acrylate was used as an end-capping agent, 40% of methyl methacrylateas a reactive diluent, 10% of dimethylol propane tetracrylate as a crosslinking monomer, 7% of hydroxyethyl diacrylate phosphate as an adhesion promoter, 4% of 1173 as a photo-initiator, and a curing time of 120 s. UV-curable resin exhibited the best coating properties: pendulum hardness of 0.63, 60° gloss of 153.9, adhesion of grade 2, impact strength of 500 J m−2, and the water resistance exceeding 30 days.

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