Workspace Analysis of Spray Painting Robot with Two Working Modes for Large Ship Blocks in Ship Manufacturing

Spray painting is crucial in the process of shipbuilding and runs through the whole process of shipbuilding. In order to obtain the good coating quality during the painting process, gantry type painting robot could be used because of its resource-saving and environment-friendly characteristics. Based on the structural parameters of the spray painting manipulator with 3DOF (Degree of freedom) gantry, the kinematic model of the painting robot system can be established. From the perspective of the two commonly working modes, namely 3P3R robot structure and the 3P6R redundant robot structure, their spraying workspace are analyzed. The result shows that the workspace volume of the 3P6R robot is much larger than that of the 3P3R robot. However, the inverse kinematics solution of 3P3R robot has analytical solution, which makes the control accurate and easy to use, and through the simulation, we can give the theoretical basis for the engineering.

The effect of paper coatings containing biopolymer binder and different natural pigments on printability

Paper is an environmentally friendly, recyclable material whose main material is cellulose, which can be obtained from all kinds of trees and plants, used as writing, printing and packaging material. Due to its structural properties, papers are not resistant to temperature and humidity, as well as problems with ink transfer with its porous structure and experienced negative printability properties. In recent years, especially the growth of the packaging industry has increased the demand for papers with improved printability properties. In order to obtain better printability properties from papers, some processes can be performed in paper production, as well as some surface treatments after production. These processes are paper coating, sizing and calendering. Paper coatings are generally water-dispersed coating solutions with one or more pigments, binders and certain additives to improve the desired properties. With these processes, by filling the gaps between the pores of the paper, a shapely and smooth surface is obtained and good printability is obtained together with the optical and physical properties of the papers. In this study, the interactions and printability properties of different types of pigments with xanthan gum binder were investigated by preparing paper coating formulations using calcium carbonate, barite and talc pigments and xanthan gum as binder. As a result, xanthan is a good coating binder and CaCO 3 {\mathrm{CaCO}_{3}} from the compared pigments is the most suitable compared to the other 2 pigments, considering all the studied areas.

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.

Enhancement of Anticorrosive Performance of Renewable Cardanol Based Polyurethane Coatings by Incorporating Magnetic Hydroxyapatite Nanoparticles

The present investigation demonstrates renewable cardanol based polyol for the formulation of nanocomposite polyurethane (PU) coatings. The functional and structural features of cardanol polyol and nanoparticles were studied by FT-IR and 1H NMR spectroscopic techniques. The magnetic hydroxyapatite nanoparticles (MHAP) were dispersed in PU formulations to develop nanocomposite anticorrosive coatings. The amount of MHAP in PU formulations was varied from 1-5%, increase the percentage of MHAP increases the anticorrosive performance as examined by immersion and electrochemical methods. The nanocomposite PU coatings shows good coating properties viz., gloss, pencil hardness, flexibility, cross-cut adhesion and chemical resistance. Additionally, the coatings also studied for surface morphology, wetting, and thermal properties by scanning electron microscope (SEM), contact angle, and thermogravimetric analysis (TGA), respectively. The hydrophobic nature of PU coatings increased by addition of MHAP and optimum result (1050) was observed in 3% loading. The developed coatings revealed hydrophobic nature with excellent anticorrosive performance.

Nanostructured Black Nickel Coating as Replacement for Black Cr(VI) Finish

This work compares different electrodeposition procedures to produce nickel black coatings as greener and less toxic alternatives to Cr(VI)-based coatings used in different applications. Nickel and nickel-plated brass served as substrates in studies with a Hull cell and polarization curves. After a set of comparative experiments, the best electrodeposition procedure was further studied and optimized. Optimal conditions were found with a bath consisting of 75 g/L NiCl2·6H2O + 30 g/L NaCl and a current density of 0.143 A dm−2 applied for 5 min at room temperature. Furthermore, a pre-treatment with 18.5 vol.% of hydrochloric acid in water was found to be necessary to warrant good coating adhesion to the substrate. The black color is attributed to the development of a nanostructured surface that absorbs the incident light. Corrosion testing was performed in 0.5 M NaCl aqueous solution using electrochemical impedance spectroscopy (EIS) and polarization tests.

Modification of sodium bicarbonate and its effect on foaming behavior of polypropylene

As a potential physical blowing agent, sodium bicarbonate (SB) is environmentally friendly and low in cost, but its low decomposition temperature cannot meet the requirements of polyolefin foam materials. Herein, for enhancing the thermal properties of SB, a modified way was offered to fabricate various SB-based capsules via suspension polymerization. As the modified SB-based capsules, epoxy resin (EP) accompanied with several organic acids was successfully coated on the surface of SB, serving as heat-insulation layer of SB. Various physicochemical characterizations provided reliable evidences for the good coating effect, and the thermal performance of the modified SB was improved. Further, the composite SB capsules were applied for the foaming of polypropylene (PP), and the foaming behavior of the SB-based capsules in PP was significantly improved, with more uniform distribution, smaller cell diameter, and higher cell density. In all, this work fully proved that the coated shells enhanced the thermal properties of SB, and the modified SB capsules significantly improved the foaming quality of foamed PP.

Microscopic Characteristics and Properties of Fe-Based Amorphous Alloy Compound Reinforced WC-Co-Based Coating via Plasma Spray Welding

Plasma spray welding, as one of the material surface strengthening techniques, has the advantages of low alloy material consumption, high mechanical properties and good coating compactness. Here, the Co alloy, WC and Fe-based amorphous alloy composite coating is prepared by the plasma spray welding method, and the coating characteristics are investigated. The results indicate that the coatings have a full metallurgical bond in the coating/substrate interface, and the powder composition influences the microstructures and properties of the coating. The hardness of coatings increases with the mass fraction of the Fe-based amorphous alloy. The spray welding layer has a much higher wear resistance compared with the carbon steel, and the Fe-20 exhibits a superior wear resistance when compared to others. The results indicate that the amorphous alloy powders are an effective additive to prepare the coating by plasma spray welding for improving the wear resistance of the coating.

Film formation and foamability of cellulose derivatives: Influence of co-binders and substrate properties on coating holdout

Foams were prepared from hydrophobically modified ethyl(hydroxyethyl) cellulose (EHEC), methyl nanocellulose, and native microfibrillated cellulose (MFC). Their film- and foam-forming abilities, stabilities, and suitabilities for foam coating on different substrates were investigated. The role of EHEC as a polymeric stabilizing agent was also studied. The EHEC-MFC foams showed greater stability and water-holding ability under pressurized dewatering than MFC foams prepared in the presence of a surfactant. A foam could be created with methyl nanocellulose without any foaming agent. Selected nanocellulose gels and foam formulations were used to coat various substrates. The surface was efficiently closed by gel and foam coatings prepared from the methyl nanocellulose and EHEC solutions, which was ascribed to good coating holdout. Coatings on papers with different levels of smoothness/density and hydrophobicity/ hydrophilicity confirmed that foam-substrate interactions affected the coat quality. The air permeance was reduced by 99% and 64% with a methyl nanocellulose coating and an EHEC-MFC coating, respectively. An EHEC-MFC coating created a hydrophobic surface on a hydrophilic substrate, and methyl nanocellulose improved the oil resistance even at a low coat weight.

Effect of Urea-Formaldehyde (UF) with Waterborne Emulsion Microcapsules on Properties of Waterborne Acrylic Coatings Based on Coating Process for American Lime

The purpose of this paper is to explore the effect of urea-formaldehyde (UF) with waterborne emulsion microcapsules on the optical, mechanical and aging resistance properties of waterborne coatings from the perspective of coating process. In this paper, the microcapsules were prepared with UF resin as the wall materials and waterborne emulsion as the core materials. Based on the coating process, the optical, mechanical and aging resistance properties of the waterborne acrylic coatings with microcapsules for American lime were tested. The good coating process is three layers of primer, two layers of topcoat, and adding microcapsules into primer. The results showed that the coating process had little effect on the color difference of the paint film with microcapsules, the gloss of the paint film prepared by the good coating process was basically not changed, and the mechanical properties of the paint film were good. At this time, the hardness grade of the paint film was 3H, the adhesion was grade 0, the impact resistance was 110.0 N·cm−2, and the elongation at break was 29.7%. The microcapsules added to the primer had better liquid resistance than those added to the topcoat. The paint film had good stability and aging resistance, and could inhibit the generation of microcracks to a certain extent. The paint film prepared by the good coating process had better comprehensive performance. This work provides a technical reference for self-healing of the waterborne coatings on American lime.