Effect of Polyurethane Non-Transparent Coating Process on Paint Film Performance Applied on Modified Poplar

Whether modified poplar can obtain a qualified or even excellent finishing effect on European and American furniture is worthy of deep study. To evaluate whether the conventional non-transparent coating process is suitable for modified poplar, a multi-level hybrid orthogonal experiment method was carried out to start research on how factors affect the paint film performance of the non-transparent coating process. The effect of experimental factors and levels on paint film performance is pointed out, and the optimal factors and levels are found. Parameter optimization of the polyurethane non-transparent finishing process based on modified poplar is carried out. An application basis was provided for the extensive use of modified poplar wood as a substrate in the European and American furniture markets. The conclusions are: (1) gloss of paint film can be improved by increasing the number of nitrocellulose (NC) lacquer transparent topcoats, (2) adhesion and thickness of paint film can be improved by polyurethane (PU) sealing primer, (3) the initial paint film’s abrasion is influenced efficiently by the coating process and coating sanding. PU sealing primer has an efficient influence on the later abrasion of paint film. The effect of modified poplar surface pretreatment on the mass loss of paint film tends to be stable.

Experimental study on mechanical property and stone-chip resistance of automotive coatings

The damage of automotive coatings caused by stone impact is a problem that has attracted great attention from automotive companies and users. In this work, experiments were conducted to investigate the dynamic tensile properties and stone-chip resistance of automotive coatings. Four kinds of paint films and three typical coatings (single-layer electrocoat coating, single-layer primer coating, and multilayered coating) were used. Under dynamic tensile load using split Hopkinson tension bar (SHTB), the engineering stress-strain curves of the paint films at medium and high strain rates (from 50 to 600 s-1) were obtained. Results indicated that the mechanical properties of the paint films exhibited strong nonlinearity and strain-rate correlation. A modified anti-impact tester was used to complete repeatable single impact tests. The effects of some key parameters, i.e., impact velocity, impact angle, and paint film thickness, on the stone-chip resistance of coatings were systematically investigated. The influence of contact type under high-speed impact conditions was investigated as well. The surface morphologies of the coatings after impact were examined by scanning electron microscopy (SEM), and the failure mechanism of the coatings under normal/oblique impact was discussed. In all experiments, the paint films showed brittle fracture behavior.

Understanding and optimizing Evolon® CR for varnish removal from oil paintings

Evolon$$^\circledR$$ ® CR is increasingly used in paintings conservation for varnish removal from oil paintings. Its key benefits over traditional cotton swabs are limiting solvent exposure and reducing mechanical action on the paint surface. However, this non-woven microfilament textile was not originally engineered for conservation use and little is known about its chemical stability towards organic solvents. Moreover, the physical processes of solvent loading and release by Evolon$$^\circledR$$ ® CR, as well as solvent retention inside paint after cleaning, have not been studied. These three topics were investigated using a multi-analytical approach, aiming for an improved understanding and optimized use of Evolon$$^\circledR$$ ® CR for varnish removal. Our results show that the tissue is generally chemically and physically stable to organic solvents when exposed on timescales that are typical in conservation practice. However, a pre-treatment step of Evolon$$^\circledR$$ ® CR is necessary to avoid the release of unwanted saturated fatty acids into the paint during varnish removal. We show that the primary mechanism of solvent uptake by the fibers is adsorption rather than absorption and that the dominant factor dictating the maximum solvent load is the volume of the voids between the fibers. Finally, solvent induced dynamics after application of solvent-loaded Evolon$$^\circledR$$ ® CR within the paint film was monitored using portable laser speckle imaging on model paints. A method to quantify solvent-retention in real-time was developed and revealed that the presence of varnish on paintings results in lower dynamics of solvents within the paint in comparison to unvarnished paint. Comparing various solvents, it was found that cleaning with acetone resulted in a roughly six-fold increase in dynamics compared to ethanol and isopropanol.

Study on Manufacturing Environmentally Friendly Alkyd Paint

The article presents results of studying and manufacturing environmentally friendly alkyd paint. By producing a polysaccharide intermediate emulsion (LPR), about 20% of water to total paint volume was added. Mechanical properties (impact resistance, flexural strength, adhesion) of paint films were studied. In addition, the paper presents results of thermal stability, 10-cycle UV-thermo-humidity complex stability of paint film. Ability of films to withstand 03-cycle heat shocking of films at temperatures of + 50 oC and -50 oC was investigated. The properties of studying paint were compared with those of an alkyd paint of Hanoi Synthetic Paint Company. Results show that the environmentally friendly alkyd paint has less volatile organic compounds (VOC), uses a smaller amount of toxic solvents, while its properties are comparable to common alkyd paint.

Effect of Paint Process on the Performance of Modified Poplar Wood Antique

Modified poplar wood is used as the substrate, based on the surface coating process and actual operation requirements of European and American furniture, and the painting process is studied. Four different paint coating methods are applied to modified poplar wood that has undergone different surface pretreatments. The gloss and adhesion of the coating system were measured. The difference in paint film performance of different paint finishes on the modified poplar with different surface pretreatments was discussed. The reasons were analyzed to establish the corresponding relationship between wood surface performance and paint film performance and obtain the best coating process parameters. The number of passes of nitrocellulose (NC) transparent primer was appropriately increasing, and the adhesion of the overall paint film was improved through the bonding between the films after sanding. NC transparent primer has the function of weakening the surface gloss. NC transparent topcoat has the effect of improving gloss. The proper use of PU sealing primer is beneficial to improve the gloss of the paint film, but excessive use will not produce any effect. The paint process of Group C is more suitable for the antique, old-fashioned process of European and American furniture from the perspective of the glossiness of the paint film.

Preparation and Performance of Thermochromic and Self-Repairing Dual Function Paint Film with Lac Resin Microcapsules and Fluorane Microcapsules

Microcapsules with lac resin as the core material and urea-formaldehyde resin as the wall material were prepared by in situ polymerization, and then the lac resin microcapsules and fluorane microcapsules were added into a water-based primer or topcoat, respectively, to prepare water-based coatings with dual functions of thermochromic and self-repair. The effects of different methods of adding microcapsules on the optical properties, mechanical properties, self-repairing properties, and the aging resistance of water-based paint film were investigated, so as to prepare water-based paint film with the best discoloration and self-repairing functions. The results showed that the paint film with 10.0% fluorane microcapsules in the topcoat and 5.0% lac resin microcapsules in the primer had better comprehensive properties, and the paint film changed from yellow to colorless at 32 °C, with a color difference of 68.9, hardness of 3H, adhesion grade of 0, impact resistance of 13.0 kg∙cm, and elongation at break of 20.0%. The resistance of the paint film to NaCl, ethanol, and detergent was grade 2, with slight discontinuous marks, and the resistance to red ink was grade 3, with slight marks. The lac resin microcapsules have good aging resistance, which can enhance the aging resistance of the paint film with fluorane microcapsules. The gap width of the paint film was repaired by 2.1 µm, the self-repairing rate was 12.3%, and the paint film with lac resin microcapsules had a better crack inhibition effect. The results have provided a reference for multifunctional wood coatings.

Effect of Microcapsule Concentration with Different Core-Shell Ratios on Waterborne Topcoat Film Properties for Tilia europaea

The effects of the core-shell ratio and concentration of urea formaldehyde (UF) resin-coated waterborne acrylic resin microcapsules on the optical properties, mechanical properties and liquid resistance of waterborne topcoat coatings on the surface of Tilia europaea were investigated. With the increase of microcapsule concentration, the color difference and hardness of the paint film gradually increased, the gloss and adhesion of the paint film gradually decreased, and the impact resistance and elongation at break of the paint film increased first and then decreased. With the increase of the core-shell ratio, the hardness and impact resistance of the paint film increased first and then decreased, and the adhesion of the paint film decreased gradually. Red ink had a great influence on the liquid resistance of paint film. When the core-shell ratio of UF-coated waterborne acrylic resin microcapsule was 0.58:1 and the microcapsule concentration was 10.0%, the comprehensive performance of paint film on Tilia europaea was better. The prepared self-healing microcapsules applied to the waterborne coatings committed to prolonging the service life of the paint film.

Effect of Water-Based Acrylic Acid Microcapsules on the Properties of Paint Film for Furniture Surface

In this paper, self-healing microcapsules with urea formaldehyde coated Nippon water-based acrylic acid were prepared, and the performance of water-based topcoat paint film added with self-healing microcapsules and the repair effect of microcapsules were investigated. The results show that when the content of microcapsules in water-based topcoat paint film on the surface of wood increased, the color difference and hardness rose gradually, the gloss and adhesion declined gradually, the impact resistance and tensile strength at break rose first and then declined. The 0.67:1 core-wall ratio microcapsules had a better micromorphology, and the water-based topcoat paint film with 0.67:1 microcapsules had a certain repair effect. The microcapsules were added to the water-based topcoat paint film to repair the coating to a certain extent, which provide technical reference for prolonging the service life of water-based topcoat paint film for the furniture surface.

The effect of SiO2 nanoparticles in polyurethane paint formulation on metal surfaces

Polyurethane (PU) paint is being widely used in industry and life. Currently, nanotechnology can create a variety of materials as small as nanometers with many applications, it has brought many outstanding properties to PU paint. The aim of this study is to investigate the effect of SiO2 nanoparticles in PU paint formulation on metal surfaces. We created a sample of two-component PU paint, part A is Desmophen A-160, Bentone 34, BYK 066, Disper 710S, Foamex N, Airex 900, TiO2, SiO2 nanoparticles, BaSO4, Cloparafin, Xylen, Thinner 132, Desmodur N75, and part B is a curing agent Desmodur N75. Methods of analyzing the properties of the PU paint film are based on Vietnam standards. The study results showed that SiO2 nanoparticles have increased the properties of the PU paint film, improving the Impact and Glossy of the PU paint film. SiO2 nanoparticles increase from 1% to 6% by weight, the Impact increased by about 21.62% (74 to 90 kg.cm), Glossy 600 increased by about 13.75% (80 to 91). SiO2 nanoparticles are a good coating substance in PU paint, it improves the properties of the paint film, it increases the Impact and Glossy for the paint film. The higher the rate of SiO2 nanoparticles, the better the properties of the PU paint film. Because the cost of nanomaterials is higher than that of normal coating materials, the nanomaterial should only be added with a ratio of about 2-4% by weight.

The effect of TiO2 Nanoparticles in Epoxy Paint Formulation on Metal Surfaces

Currently, epoxy paint is being widely used in the industry. Nanotechnology can create many small nanometer-sized materials with many applications, it has brought many outstanding properties to epoxy paints. The aim of this study is to investigate the effect of TiO2 nanoparticles in epoxy paint formulation towards metal surface. We created a sample of two-component epoxy paint, part A is epoxy resin, anti-sedimentation, dispersant substance, foam breaking agent, cover substance, solvent, other additives, and part B is a curing agent for epoxy resins. Methods of analyzing the properties of the epoxy paint film are based on Vietnam standards. TiO2 nanoparticles are a good coating substance in epoxy paint. The study results showed that TiO2 nanoparticles have increased the properties of the epoxy paint film, improving the Impact and Glossy of the epoxy paint film. TiO2 nanoparticles increases from 1% to 6% by weight, the impact increased by about 18.75%. (80 to 96 kg.cm), Glossy 600 increased by about 12.79% (80 to 97). Adding TiO2 nanoparticles to epoxy paint has increased Impact and Glossy for the paint film. The higher the rate of TiO2 nanoparticles, the better the properties of the epoxy paint film. Therefore, TiO2 nanoparticles are a good coating in epoxy paint, it improves the properties of the paint film. Because the cost of nanomaterials is higher than that of normal coating materials, the nanomaterial should only be added with a ratio of about 2-5% by weight.