Study On Technology Of Flame-retarded Medium-density Fiberboard

Because of a good physical and mechanical performance, Medium-density fiberboard (MDF) was widely utilized in the many fields such as construction, decoration, furniture manufacturing and vehicle shipping industry. However, MDF is a combustible material and easy to be ignite when the fire broke out. Therefore, the study of the flame-retarded MDF is one of the great significance of the man-made board industry.In this study, The medium density fiberboard is prepared for using the multi-carbohydrate-nuclear flame retardant and flame-retarded microcapsule. At last the mechanical property and flame retardance of the MDF is analyzed,then get the key technology parameters of the flame-retarded MDF and completed trial production of Furen Wood Industry Co.Through this study, we get the following conclusions:(1)the analysis of starch-based P-Si-Al hybrid flame retardant performance.The flame retardant is an organic-inorganic hybrid flame retardants which contained in flame-retarded elements such as Al, P and Si, etc. The flame-retarded mechanism includes mechanism of cover, charcoal mechanism and thermal forming mechanism, etc. The silicate and boride of flame retardants melt covering on the surface in the fiber, which have the effect of heat insulation and promotion of charring.(2)the analysis of microcapsule flame retardantsWhen heated, these flame-retarded microcapsule decompose and liberating the fire- retarded gas and release phosphate inorganic acid at the same time. In addition, the phosphates of microcapsule will result in the timber charring quickly.(3)The effects of flame retardants liquid on the flame retardancy and mechanical properties of fire-retardant MDF.Flame-retarded liquid can improve the combustion properties of MDF.As the result,we can find that the liquid of flame retardant A and B complex ratio of 1.3:1, and A adding amount is 4.8%, the pHRR decreased by 36%, THR decreased by 14%, and EHC decreased by 5%. On the other hand, Fire-retarded MDF has dense, flat, solid carbon layer after burning test.The flame-retarded liquid has great influence on physical and mechanical properties of MDF. Although flame retardant makes the plate’s physical strength drop, the strength are still higher than the national standard requirements. When the flame-retarded liquid A and B complex ratio of 1.3:1, and A adding amount is 4.8%, the physical and mechanical properties of flame-retarded MDF is best.(4)The effects of microcapsule flame retardants on the flame retardancy and mechanical properties of fire-retardant MDF.The result shows that the flame-retardant property of MDF is enhanced obviously by adding flame-retarded microcapsule.With the increase in microcapsule’s dosage, the LOI of the MDF increased significantly. When the microcapsule adding amount is 15%, the pHRR of the flame-retarded MDF decreased by 54%, THR decreased by 44%, and EHC decreased by 31%. TSP decreased by 75%. In addition, With the amount of microcapsule adds 15%, the strength of the carbon layer has increased gradually. Considering the high cost of microcapsule, choose 12% as the basis of the next test.The result shows that a good addition of flame-retarded microcapsule is 12%, the best ratio of flame retardants liquid A and B is 1.3:1.(5)The analysis of productive trialProductive trial shows that the influence of flame retardants on the mechanical property of MDF is unconspicuous, but it will increase TS24 of MDF. We can increase the amount of paraffin appropriately to improve TS24. On the other hand, the accuracy and uniformity of microcapsules’ addition is the important problem with present.