Manufacturing Technology And Performance Of Folyethylene Film Reinforced Flexible Decorative Veneers Treated By Plasma

To improve the utilization rate of wood and product added value,the paper systematically studied the manufacturing technology and performance of flexible decorative veneers reinforced with folyethylene(PE)film and treated by plasma,analyzed the influencing factors and control mechanism of the crimp deformation,and optimized the relevant finishing process parameters of the flexible decorative veneer.It provides a theoretical basis for the industrial production and application and has important theoretical significance and practical values.The main researches and results are summarized as follows:(1)With the PE film thickness 0.03 mm,hot-pressing pressure 1.0 MPa,temperature150℃ and time 120 s,the flexibility of the polyethylene film reinforced flexible decorative veneer is good,for the diameter of the steel bar curl of merely 4 mm,and the peel strength is good of 0.51 MPa.However,the crimp deformation is obvious.(2)The surface properties of the decorative veneer modified by different plasma conditions are as followsa)The air dielectric barrier discharged low temperature plasma can obviously improve the wettability of decorative veneer,and have a lot to do with the discharge power and the processing speed.With the plasma processing power of 3 kW and the processing speed of 3m/min,the surface wettability improvement of rosewood,teak and black walnut was the most significant,whose surface water contact angle was minimized by 34.28% 26.05% and 39.77%,respectively,the surface free energy was increased by about 77.27%,1.26 times and 1.28 times,while the surface dynamic attenuation rate constant K value was increased by 4.24 times,4.24 times and 6.65 times respectively.When the plasma processing power is 2 kW and the processing speed is 4 m/min,the surface contact angle of red oak and northeast China ash fell the most obviously,which was reduced by 47.41% and 37.31% respectively,the surface free energy was increased by 59.09% and more than 1 times respectively,and the surface dynamic attenuation rate constant K value was increased by 2.68 times and 4.38 times respectively.b)After DBD plasma treatment,the key content of C2 of black walnut,red oak,northeast China ash and rosewood decorative veneer surface was significantly increased.However,the surface oxidation reaction of teak decorative veneer treated by plasma was relatively weak for the key content of C2 decreased from 17.1% to 10.5%.c)Plasma treatment can etch the decorative veneer surface and increase its surface roughness.The different increment of the roughness for decorative veneer is associated with the wood material and micro structure.Under the experimental conditions,the surface roughness of teak was small,the black walnut was opposite bigger and the rosewood was in between.With the processing speed of 3 m/min,the roughness amplitude of black walnut,teak and rosewood decorative veneer was all at its largest,for about 54.4%,41.82% and 45.63%respectively.(3)The optimal processing parameters for making folyethylene film reinforced flexible red oak decorative veneer were 0.6 MPa pressure,120℃ temperature and hot-pressing for 150 seconds with 4 m/min speed.The optimal processing parameters for making folyethylene film reinforced flexible rosewood decorative veneer were 0.6 MPa hot-pressing pressure,120 ℃temperature and hot-pressing for 120 seconds with 3 m/min processing speed.In the optimal conditions,the peel strength can reach more than 0.5 kN/m and transverse tensile strength can increase to more than 4.1 MPa,dipping peel performance test can achieveⅠclass.(4)The influence of plasma treatment on folyethylene film and rosewood decorative veneer and the hot pressing composite interface bonding performance are as follows:a)Plasma modification can both reduce the surface contact angle of rose decorative veneer and folyethylene film and increase the surface free energy.With the plasma processing power of 3 kW and the processing speed of 3 m/min,the surface wettability improvement is the most significant for both of them.The dipped contact angle of water and methyl iodide on folyethylene film surface decreased by 36.96% and 61.35% respectively,and a 74.42%increase appeared in free energy,which the polarity force increased about 10 times than the dispersion force.b)Plasma modification can improve the surface activity of decorative veneer and folyethylene film,and increase the oxygen-containing groups,for the O element content of folyethylene film treated by plasma increased 10.72 times than untreated,O/C concentrations increased 13.11 times.The surface oxidation degree of folyethylene film was significantly higher than rosewood decorative veneer,which was better for the chemical reaction in the process of gluing.c)Plasma modification can etch effectively on the folyethylene film surface,improve the surface roughness and reduce the initial viscosity and melt temperature.It was benefit to increase the bonding area and improve the bond strength between the rosewood decorative veneer and the folyethylene film at a low hot pressing temperature for 116~120℃,which can relieve the crimp deformation.(5)The hot-pressing temperature,thickness of folyethylene film and decorative veneer and tree species have a great influence on the crimp deformation of flexible decorative veneer.The lower of the hot-pressing temperature,the smaller the crimp deformation is.When the parameters were 0.2 mm thickness of decorative veneer and 0.03 mm thickness of folyethylene film,the curl of the composite was minimum.The curl is relatively small for the decorative veneer of relative big density and compact structure.The author proposed a method to prevent the crimp deformation of flexible decorative veneer,for lowering hot-pressing temperature joint with concave and convex die instant reverse winding cooling.(6)The hot-pressing temperature,hot-pressing time has significant influence on the bond strength of the surface finishing of folyethylene film enhanced red oak flexible decorative veneer,and hot-pressing pressure with temperature,hot-pressing temperature with time has significant interaction effects on the surface bond strength.With the hot-pressing temperature of 130℃,time of 3 min and pressure of 1.0 MPa,the surface bond strength can be up to the maximum of 1.70 MPa.