Study On Processing Technology Of Straw Based Panel With Fire- Retardant FRW

This paper explored the effect of MDI,UF and FRW content on the mechanical and fire retardant property of straw based panels with surface alkali liquor processing.The material ratio and hot-processing parameters were optimized.In order to manufacture the straw based panel with low toxic and fire retardant,veneer overlaying was carried out under the optimized condition.Finally,the neural network techniques were used for the prediction of physical and mechanical properties of straw based panels.The results were showed as followed:(1) The conductivity and diffusion coefficient K of the straw material after alkaline liquid treatment increased obviously.This indicated that alkaline liquid treatment improved the surface wet ability of straw,which is helpful for the infiltration of resin.The results of orthogonal test showed that the optimized treating condition was alkaline liquid concentration as 0.4-0.8%,alkaline dosage as 1:2.5-1:4.5,alkaline-treated time as 12h-48h.(2) The IB of straw based panels after treated increased remarkably and it could satisfy the national standard.The 2hTS,MOE and MOR decreased slightly.The reason for this change is the ruin of fiber structure and the waxiness;the improvement of the straw surface wet ability is helpful to the forming of chemical bond.(3) The variance analysis of physical and mechanical property of straw based panel showed that MOE,MOR,IB and 2hTS were significantly affected by the content of MDI.With the increasing of resin content,the property of MOR,MOE and IB increased.The 2 hTS decreased with the increasing of FRW content.(4) The variance analysis of the fire retardant property of straw based panel showed that TTI,pkHRR and peak value appearance time were not affected by the MDI,UF and FRW content significantly.With the increasing of FRW content,the pkHRR decreased meanwhile. The existence of boric acid in FRW decreased the HRR that is the keynote of fire retardant mechanism.(5) The results of orthogonal test showed that the optimized processing condition was MDI content as 3%,UF resin content as 6%and the FRW content as 10%.The physical and mechanical value of straw based panel that pressed under the optimized condition were MOE as 2423MPa,MOR as 29 MPa,IB as 0.63 MPa,2hTS as 7.9%.Compared with untreated straw based panel,the fire retardant property of the straw based panel with FRW was obviously improved.(6) IB values of straw based panels with veneer and melamine overlaying exceeded the national standard,and they could be used in furniture manufacture directly.(7) Based on the three layers BP neural network techniques,the content of MDI,UF and FRW were chosen as the input parameters,corresponding to the MOR,IB and the fire retardant parameters HRR.The result showed that the correlation coefficient between the actual value and target output value is 0.99.Considering the step and the time of training,the hidden layer was set to 10 in the model.The correlation coefficients of fitting data between the trained output value and the target sample were 0.999,0.994 and 1 separately.This indicated that the result of the model was good based on the BP neural network,and more improvement was needed in the future.