Development Of Integrated Materials Based On Poplar Compression Modification And Surface Decoration Technology

Because of its short growth cycle and high yield,fast-growing poplar is considered to be a powerful solution to solve the shortage of wood supply and meet human needs.However,due to its soft quality,low strength,poor stability and weak texture,it is difficult to be widely used with high value.In view of the above-mentioned disadvantages and bottlenecks of the most important fast-growing plantations in Jiangsu,the self-compression enhancement technology isused to focus on solving the key problem of low physical and mechanical properties of poplar;The bottleneck of poor wood surface texture and lack of aesthetics;then the two technical solutions are organically combined to prepare functional materials with both structure and decoration,facing the economic battle field of national households,and realizing fast-growing poplar high-value green solutions.Firstly,the compression and stress relaxation properties of fast-growing poplar were explored to provide theoretical support for the compression-enhancing technology of fast-growing poplar.On this basis,the optimal process parameters for compression-enhancing of fast-growing poplar were screened through two-factor experiments of softening time and compression ratio.;On this basis,the pattern design is carried out for the weak surface texture of the compressed wood,the pattern style is screened through a questionnaire survey,and the decorative pattern of the poplar surface is realized by means of the wood surface imprinting technology,so as to prepare the fast-growing poplar into a structural decorative multifunctional material.The results of the study are as follows:(1)The radial direction of the transverse grain of the poplar material is more conducive to compression enhancement.Both moisture and elevated temperature can increase the plasticity of the wood.The more higher temperature,the greater the final relative deformation of the compressed wood.The compression experiment of poplar water-saturated wood was carried out by liquid immersion method.The elastic modulus,proportional limit stress and failure stress of water-saturated wood at 20℃ were all smaller than those of air-dried wood at 20℃,but the failure strain of water-saturated wood was significantly greater than that of air-dried wood.,the proportional limit strain has almost no difference,indicating that water can increase the plastic deformation of wood;the influence of temperature on the compressive properties of poplar wood was tested at 5 temperature points of 20℃,40℃,60℃,80℃,and 100℃.The elastic modulus,proportional limit stress,and failure stress all tend to decrease with the up temperature,but the failure strain and toughness coefficient increase with the increase of temperature,and the proportional limit strain has almost no difference,that is,the increase of temperature can increase.Plastic deformation of large wood;stress relaxation and deformation fixation experiments were carried out on the compressed poplar water-saturated wood.Under the condition of strain level of 30%and 50%,the initial stress and residual stress decreased with the increase of temperature,and the stress relaxation rate It does not change regularly with temperature;at the same temperature,the greater the strain level,the greater the initial stress,residual stress and stress relaxation rate.The compressive deformation of the compressed wood under the 50%strain level tends to be stable after 48h.The final relative deformation of poplar water-saturated wood is related to the temperature during stress relaxation.When the temperature increases,the final relative deformation will increase,but The difference was not significant after 60℃.(2)Process parameters for layered compression of poplar fast-growing wood:hot pressing temperature of 170℃,system pressure of 6 MPa,softening for 10minutes,and compression rate of 30%.The fast-growing poplar wood is subjected to chordwise loading and compression enhancement,and the compression pretreatment is performed by(1)selecting the method of high temperature boiling and softening.First,the layered moisture content of the material under different softening times is measured to verify the feasibility of layered compression.Second,carry out a two-factor experiment of softening time(10,20,30min)and compression rate(20%,30%,40%),boiled and softened for 10min,and compression rate of 30%is the best compression process parameter.Under this process,The density of the specimen increased by 53.48%to 0.66g/cm3,the flexural elastic modulus increased by 159.23%to 158.86MPa,the static bending strength reached 59.27%to 10GPa,and the surface hardness increased by 91.97%to 3300N,which is in line with QB Strength standard requirements of GB/T 4456-2013 "High-strength decorative countertops for furniture".(3)Prepare the structure-decoration integrated material,and explore the influence of the surface decoration thickness on the mechanics and aesthetics of the integrated material through the experiment of the influence of the surface decoration thickness on the performance of the structure-decoration material.Experiments show that the thickness of 2mm pattern has no obvious effect on the overall mechanical properties of the integrated material.Although the parameters are slightly decreased,it still meets the strength standard requirements of QB/T 4456-2013 "High-strength decorative countertops for funrniture",and the aesthetics meet the target.Secondly,for the application of furniture and wardrobe doors,the questionnaire of "Questionnaire on the Choice of Patterns of Furniture and Wardrobe Doors" was designed and the results were analyzed.The results were analyzed to obtain the following results:artificial ideological patterns were the most popular,accounting for 44.32%;Medium:Freehand style is the most popular,accounting for 37.3%;in the layout of patterns:the most popular is continuous layout,accounting for 43.78%,55.14%of the respondents pay more attention to the overall matching of patterns and home style,44.86%Then choose the pattern design itself.The research results are used as the theoretical basis for the decorative backing plate pattern to design the backing plate,use CAD and 3DMax to draw the wood surface decoration effect diagram,and obtain the structure-decoration integrated material through the poplar surface decoration technology;finally,the surface decorative pattern is satisfied.The results of the questionnaire survey show that the fringe decorative pattern is generally welcomed by the surveyed population.This subject uses layered compression enhancement technology to make poplar meet the physical and mechanical strength of furniture countertops;directly construct various decorative patterns on the surface of poplar,and prepare integrated structural decoration materials to meet the individual needs of different groups of people.Green,efficient and high-value utilization provides innovative solutions.