Study On Light Fastness Of Dyed Veneers Based On Reconstituted Decorative Materials

The excellent performance and renewable nature of wood have made it an indispensable and important decoration material in people’s production and life,while modern people’s consumption concept tends to be more and more close to nature.The amount of wood,especially wood with beautiful patterns and colors,is increasing,but wood resources are becoming increasingly depleted.With the decreasing natural forest resources,it is an important issue for the wood processing industry to make comprehensive,rational and alternative use of forest resources,especially scarce and precious species of wood resources,to meet the needs of social development.This paper takes dyed veneer as the research object to study the dyeing and lightfastness of veneer used for group blanks,and selects red double azo structural dyes,yellow double azo structural dyes and blue anthraquinone structural dyes to dye three common woods,namely,ayous,linden and poplar,mainly including: the analysis of the characteristics and dyeing effect of the three woods,the study of the effect of bleaching modification on the dyeing and lightfastness of veneer,the study of the effect of chitosan modification on the dyeing and lightfastness of veneer At the same time,the lightfastness of dyed veneer,the surface morphology of dyed veneer and the changes of chemical bonds after xenon light were analyzed by scanning electron microscopy(SEM)and Fourier infrared spectroscopy(FT-IR).The main results of the study are as follows:(1)In this paper,we analyzed the differences in the basic wood properties and lightfastness of three types of wood,namely,ayous,linden and poplar,by means of dyeing tests,and obtained that the lightfastness of wood materials are,in order,ayous,poplar and linden;we conducted an enterprise research on the application of common veneer blanks,and concluded that ayous is suitable for simulating oak,black walnut and ebony products,linden is suitable for simulating sourwood,and poplar is suitable for simulating silver pear;we used three kinds of dyes to dye the three types of wood,and concluded that the lightfastness is,in order,linden,poplar and ayous;we used three kinds of dyes to dye the three types of wood,and concluded that the lightfastness is,in order,good to bad;(2)Using the bleaching modification test,the results showed that the modification had a greater effect on the veneer material color,among which,the staining rate of linden red and blue veneer and ayous blue veneer tended to be the same before and after bleaching,the final staining rate of other veneers were less than the original wood staining,the final staining rate of ayous red and yellow veneer,linden yellow veneer,poplar red,yellow and blue veneer decreased by 4.54%,2.91%,5.45%,10.75%,2.66%,9.55%,light resistance performance,all decreased by 0.5～1.5,the degree of difference;through microscopic characterization test,the results show that bleaching has a greater impact on the appearance of veneer morphology,xenon light on the veneer surface morphological deterioration is not obvious;(3)Using chitosan modified veneer test,the results showed that when pretreating veneer with 3% concentration of chitosan aqueous solution,the three woods showed significant improvement in material color,dyeing rate and lightfastness.Under the same dyeing conditions,the final staining of the pretreated wood was 2-3 times that of the original wood,the surface color depth value of the veneer was significantly increased,there was almost no difference in the xenon light test for 6h,and the lightfastness could reach more than 4.By microscopic characterization test,the results showed that the surface grain pores and duct surface of veneer were covered with dye after chitosan modification,and the adsorption of dye by wood was enhanced after chitosan modification;(4)Using ultrasound to modify the dyeing process,the results showed that the staining rate was significantly improved compared with the previous water bath dyeing,the wood could reach the equilibrium staining rate in a shorter period of time,the log ultrasound staining time could be shortened by 1～2h compared with the log water bath staining,with slight variability among different woods,with ayous wood being the most obvious;(5)Optimization study of the veneer blanks coating process,using 30% of the surface area of the finished material adhesive to optimize the improvement of its blanks,the results show that the secondary processing of the veneer light resistance to improve 0.5 grade.