The effect of artificial aging on color, glossiness, pendulum hardness and adhesion to the surface of black poplar wood treated with UV curable varnish

Abstract

Black poplar wood is used for the manufacture of furniture, paneling, and plywood. In this study, the relationship between 3 and 5 layers of UV system varnish applied to black poplar (Populus nigra L.) wood and artificial aging was investigated. In addition, before and after aging (252 and 504 hours), color parameters (∆E*, ∆L*, ∆a*, ∆b*, L*, a*, and b*), glossiness, pendulum hardness, and surface adhesion resistance (pull-off) tests were performed on varnished materials. According to the results obtained, for both varnish types, a decrease in surface adhesion resistance and L* value was determined with the increase of aging time after aging conditions with UVB-313 lamps, while increases were determined for a* and b* values. ∆E* values were found to be higher than that of the 3-layer application. In addition, it was determined that the measurements made in all directions and degrees glossiness for both varnish applications decreased with increasing aging time. It was observed that the pendulum hardness of the surfaces with 3 coats application was higher than that of the 5 coat application, while decreases were observed at the end of the 252 hours in both varnish types, while an increase was obtained at the end of the 504 hours. As a result, it is recommended to use this material in line with the usage areas according to the ambient conditions of the desired hardness resistance (space floor preference).