Comparison among Parameters Affecting Vertical Vacuum Dyeing of Populus cathayana Rehd

Abstract Dyeing pale-colored plantation-grown hardwood is an effective way to meet the demand for richly colored tropical hardwoods used in decorative applications. The objective of this study was to investigate the influence of wood dyeing parameters such as vacuum pressure, vacuum time, dyeing time, and dye concentration regarding the dyeing of Populus cathayana Rehd using the vacuum dyeing system. As the height increased, the color change decreased gradually. Color change and dye uptake gradually increased with increasing vacuum pressure and dye concentration. As the vacuum time and dyeing time increased, color change and dye uptake first gradually increased until water began to be discharged, leading to a decrease of the pressure gradient in the log, and then decreased.