Study On Technology Of Texture Highlight Of Natural Light Texture Wood

This paper uses three methods to highlight texture on Poplar veneer. The first method is dipping and diffusion by economic reagent, the second method is heat treatment, the third method is hot pressed treatment. We obtain preferable reagent for highlighting texture of Poplar veneer by experimental study and practical probe and educe reasonable treatment process of highlighting respectively. Highlighted mechanism of Poplar veneer texture is analyzed by FTIR and SEM after treatment, highlighted mechanism of light texture wood is educed. Color difference of earlywood and latewood of Poplar veneer is determined and analyzed during study process. The results are obtained as follows:(1)Potassium permanganate is color developing reagent, hydrochloride is reducing agent, bleaching agent is mixture of hydrogen peroxide, ammonia water and water with 10:1:10. Color difference of earlywood and latewood of Poplar veneer increased at first and then gradually decreased with the increase in the mass fraction of potassium permanganate and the increase of temperature; color difference of earlywood and latewood of Poplar veneer increased at first and then paralleled with the increase of bath ratio and the increase of time; Parameters of potassium permanganate(3‰), temperature(95℃), time(2h) and bath ratio(15:1) are a marked impact on highlighting of texture of Poplar veneer. The best process parameters are as follows: mass fraction of potassium permanganate is 4‰, temperature is 95℃, time is three hours and bath ratio is 25:1.(2)In the test of heat treatment, Color difference of earlywood and latewood increased at first and then gradually decreased with the increase of temperature and the increase of time, parameters of temperature of heat treatment(170℃) and time of heat treatment(2h) are a marked impact on highlighting of texture of Poplar veneer. The best process parameters of heat treatment are as follows: temperature of heat treatment is 170℃, time of heat treatment is two hours.(3)In the test of hot pressed treatment, parameters of hot pressing pressure(0.5MPa) and hot pressing time (4min) are a high marked impact on highlighting of texture of Poplar veneer, and parameter of hot pressing temperature(190°C) is a marked impact on highlighting of texture of Poplar veneer. The best process parameters of hot pressed treatment are as follows: pressure of hot pressed treatment is 0.5MPa, temperature of hot pressed treatment is 190℃, time of hot pressed treatment is four minutes.(4)Known from the mechanism, chromophoric groups and auxochrome of lignin changed in the macroscopical direction; unknown material in the latewood is the key of highlighting of wood texture in the microcosmic direction, but it is no change in the earlywood by SEM; auxochrome(OH) is increased largely and chromophoric group(C=O) is changed after treatment of highlighting by IR, so color of latewood of Poplar veneer is increased which makes texture highlighting.(5) Treatment effect of hot pressed treatment is best, heat treatment is take second place, chemical treatment is the last which obtained from comparison of the three methods. Three methods have less impact on bonding properties and have no impact on painting properties.Highlighting of natural texture has universality, so using range of light texture wood is enlarged, use value and economic value are improved, new way is offered for application of fast-growing plantation and content of wood science is enriched.