Painting technology and adhesion mechanism of waterborne paint based on bamboo laminated lumber

  Objective  Bamboo laminated lumber has excellent properties and is often used in furniture, construction and other industries. The application of waterborne paint can effectively protect bamboo laminated lumber. At present, the waterborne paint painting of bamboo laminated lumber faces the problems of difficult penetration and poor adhesion of waterborne paint. Therefore, it is helpful to study the influence of painting technology and varnish and color paint on the film properties and adhesion mechanism of bamboo laminated lumber waterborne paint, which will help to solve the problem of bamboo laminated lumber waterborne coating.

  Method  Using bamboo laminated lumber as the base material, the waterborne varnish and color paint were painted by a simple and economical painting process, and film hardness, adhesion, gloss and surface roughness were tested, and the adhesion of the paint film on the bamboo laminated lumber was further explored by means of electron microscope and infrared analysis.

  Result  The hardness of the varnish film was 1H and the adhesion was grade 0, while the hardness of the color paint was 2H because it contained pigments. The presence of pigment particles affected the degree of cross-linking of the film, which made the adhesion of the paint less than grade 1, and the surface roughness was higher than that of the varnish. It showed that the coating process can maintain strong adhesion and paint film hardness, and can better protect the substrate. The surface gloss of bamboo after waterborne paint was significantly increased, and the longitudinal gloss was increased by more than 5 times, which greatly improved its decorative performance. And the total color difference value before and after varnish painting was low, indicating that varnish painting can better maintain the color of bamboo laminated lumber itself. The analysis showed that the film-forming substances in the waterborne paint had a physical and chemical bond with the bamboo substrate, which contributed to the better adhesion of the waterborne paint.

  Conclusion  This study has explored the effects of waterborne varnish and colored paint on bamboo laminated lumber and the adhesion texture of waterborne paint film, providing theoretical and technical support for waterborne painting and performance improvement of bamboo.