The Effect of Water-Based Primer Pretreatment on the Performance of Water-Based Inkjet Coatings on Wood Surfaces

Wood surface staining suffers from volatile organic gas (VOC) emissions and uneven staining at knots, and these environmental and decorative performance issues are the main restrictions in the application of wood products, indoors and outdoors. Herein, the method of wood-based panel surface staining is presented for improving environmental and decorative performance using environmentally friendly water-based inks, water-based primers, and digital inkjet coloring technology. The wood-based panels’ dye coatings were prepared with oak plank as the sample substrate, a one-component water-based primer as the interfacial adhesive, and a water-based ink as a coating agent. The application amount of water-based primer was 15 g per square meter, applied twice by a roller, and the coating thickness reached approximately 20 μm. The influence of the one-component water-based primer on the interfacial properties of water-based inkjet coatings was investigated via Fourier-transform infrared (FTIR) spectroscopy, a video contact angle analyzer, and environmental scanning electron microscopy (SEM). The results showed that the one-component water-based primer connected the plain board to the inkjet-printed coating. The addition of a water-based primer coating reduced the contact angle of the wood surface from 41.69° to 37.28° and increased wettability. This helped enhance the adhesion of the water-based inkjet coating, and the primer treatment in the semi-closed state covered the scar defects of the plain board while preserving the path of grain holes on the wood surface. With image editing and inkjet dyeing, the surface of the oak plank obtained a uniform staining effect on the primer coating while maintaining the original natural pore texture of the wood. This study proves that a one-component water-based primer pretreatment process for water-based inkjet printing coatings on wood surfaces has excellent modification ability and interface adhesion. It provides a feasible method of color modification for artificial panel surfaces.