Study On Effect Of Hydrothermal Treatment On Elm Mechanical Properties And Surface Roughness Of Peeling Microveneer

This paper selected elms as experimental material, and hydrothermal treatment as experimental method. This paper first studied tangential face shear strength parallel to grain and hardness of elms under different conditions:temperature at 40℃,60 ℃,80℃, 100℃ and boiling time of 4h,8h,12h, and analyzes the significant effect of boiling process temperature and time on shear strength and hardness. Then it used rotary cutter modified by C630-1 lathe to process the microveneer, which were softened before, aiming to study the effect of different process conditions on the roughness of veneer surface. Finally, it analyzed the peeling thickness’effect on surface roughness of microveneer. This study is aimed at providing a theoretical basis for process of peeling elms microveneer, and has a guidance to improve efficiency and surface quality of microveneer. This paper makes following conclusions:1.When process time is fixed, shear strength decreases with the increase of temperature. It declines obviously during 40℃ to 80℃ and the trend becomes flat during 80℃ to 100℃. When temperature is fixed, shear strength decreases with time. It declines fast from 4h to 8h, and the decrement is slowed down gradually after 8 hours. The author conducted reusable two-factor analysis of variance on shear strength. At the level of 0.01, temperature’s effect on shear strength is highly significant; time’s effect is significant, and the interaction effect of temperature and time is not significant.2.Elms end face hardness is higher than tangential face hardness and radial face hardness, and tangential face hardness and radial face hardness are very close. When process time is fixed, hardness of elms decreases with the increase of temperature. It drops obviously during 40℃ to 80℃ and declines slowly during 80℃ to 100℃. When temperature is fixed, hardness of elms decreases with time. It declines slowly from 8h to 12h. The author conducted reusable two-factor analysis of variance on the result of hardness test. At the level of 0.01, temperature’s effect on hardness of elms is highly significant; time’s effect is significant, and the interaction effect of temperature and time is not significant.3.With the increase of temperature, the surface roughness value declines and the quality of microveneer becomes better. Time’s effect on surface roughness is not significant. Generally peeling thickness’effect on surface roughness is as following:as the microveneer gets thicker, surface roughness parameter, or Rz increases, and the surface quality becomes worse. Under the conditions set in this study, the optimum softening temperature is 100℃ and the time is 8h.