Hadi Gholamiyan; Ahmad Javid
Abstract
In this study, the effect of thermal cycle on surface degradation and crackability of wood coatings reinforced with clay nanoparticles and changes in adhesion and gloss properties were investigated. In this study, solvent-based coatings (alkyd, polyurethane), water-based coatings (chromium and phosphorescence) ...
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In this study, the effect of thermal cycle on surface degradation and crackability of wood coatings reinforced with clay nanoparticles and changes in adhesion and gloss properties were investigated. In this study, solvent-based coatings (alkyd, polyurethane), water-based coatings (chromium and phosphorescence) and oil-based coatings (oil-based coatings) were used in Abies alba wood species. Also, techniques and tests for measuring surface cracks, tensile adhesion and gloss meter were used to analyze the results before and after thermal fatigue. The results showed that the best coating performance in all three tests of tensile adhesion, surface gloss and surface crack is chrome coating and the most unsuitable of them is alkyd coating. Moreover, the results showed that the use of clay nanoparticles before the thermal cycle did not differ much in the properties of the coating, but after the thermal cycle increased the strength of the coatings. This increase in adhesion resistance in chromium, phosphorescence, oil, polyurethane and alkyd coatings was rate nearly doubled. In addition, the use of clay nanoparticles could reduce the crackability of the coating due to thermal fatigue and improve the performance of the coatings.
Pulp and paper
Alireza Sukhtesaraie; Mohammad Azadfallah; Saeed Bastani
Abstract
Flexographic printing is the most usable technology in the packaging industry. But the lack of proper adhesion of water-based ink on cardboard coated with polyethylene is one of the most important problems. Silane adhesion promoters are considered among the best compounds used as the crosslinking and ...
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Flexographic printing is the most usable technology in the packaging industry. But the lack of proper adhesion of water-based ink on cardboard coated with polyethylene is one of the most important problems. Silane adhesion promoters are considered among the best compounds used as the crosslinking and waterproofing agents in coating and ink industries. In this study, N-(2-Aminoethyl) (3-aminopropyl) methyldimethoxysilane and 2-(3, 4-Epoxycyclohexyl) ethyltriethoxysilane were used to improve the adhesion of water-based ink on paper boarded-coated with polyethylene. Results showed that highest amount of adhesion were achieved by adding 5% of N-(2-Aminoethyl) (3-aminopropyl) methyldimethoxysilane to ink. Adding silane compounds to ink formulation increased the contact angle of the ink film on the surface of cardboard coated with polyethylene which means that inks containing silane compounds act more successful in the formation of hydrophobic surface. It is worth noting that surface tension was decreased by addition of silane components to the formulation of the ink.
Management and Economics wood
Hadi gholamian; Asghar Tarmian; Ali Abdulkhani
Abstract
In present study, the adhesion strength of polyurethane and alkyd coatings on the poplar wood (Populus nigra) was improved by nano-silane coating using sol-gel method for outdoor application. For this purpose, the boards with dimensions of 15 × 10 × 2 mm were prepared according to EN 927-5. ...
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In present study, the adhesion strength of polyurethane and alkyd coatings on the poplar wood (Populus nigra) was improved by nano-silane coating using sol-gel method for outdoor application. For this purpose, the boards with dimensions of 15 × 10 × 2 mm were prepared according to EN 927-5. The surfaces of wood specimens were modified with Tetraethoxysilane (T) sol-gel material and then, solvent-borne alkyd (AS) and solvent-borne polyurethane (PS) coatings were applied. The coated samples were placed outdoor on a platform with a slope close to Karaj latitude (36̊) for 8 months according to ISO 877 standard. In order to characterize the quality of the coatings, colorimetric, tensile adhesion (Pull off), scratch adhesion (Cross cut) and ATR-FTIR tests were performed before and after weathering. The ATR-FTIR analysis demonstrated that the wood surface was covered with silicon oxides (SiO2) attached to hydrocarbon chains. As a result of surface wood modification by sol-gel, the color and adhesion strength of polyurethane and alkyd coatings were less affected by weathering. The highest tensile and scratch adhesions were found for the combined sol-gel and polyurethane coatings.
Management and Economics wood
abdollah zamnai; Mohammad reza Mastari farahani
Abstract
In this research, the effect of oil heat-treated on the outdoor performance of coatings namely, transparent resin stain, alkydi paint, semi- transparent cellulosic stian, acrylic paint coated on eastern cotton wood was investigated. For this purpose, sound specimens with the dimensions of 50×50×2 ...
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In this research, the effect of oil heat-treated on the outdoor performance of coatings namely, transparent resin stain, alkydi paint, semi- transparent cellulosic stian, acrylic paint coated on eastern cotton wood was investigated. For this purpose, sound specimens with the dimensions of 50×50×2 mm (Longitudinal × tangential × radial) were prepared from sapwood. Test samples were treated with canola oil at temperatures of 180, 200 and 220 ° C for 4 hours. The coatings were the wet film thickness of 150µm were applied on the specimens using an applicator. The coating adhesion was measured according to ASTM D 4541 standard, and the color characteristics of the coating were measured according to ASTM D 2244 before and after a natural weathering for 180 days. The statistical analysis of the color change data showed that the effect of the oil heat-treatment on the color change depended on coating type. The statistical analysis of the adhesion strength data showed that the adhesion strength depended on the combination of weathering, oil heat-treatment and coating type.
