Study On Fire-retardant And Bending Of The Fast-growing Chinese Fir

In this paper, the object of study is the fast-growing Chinese ifr treated with a way of woodmodification which is called full cell process, Influence of modiifer on ifre-retarding, thelongitudinal compressing, the longitudinal tension of the fast-growing Chinese fir is studied.Adopt the hot water to sotfen wood that is put to use in order to further study on thelongitudinal compressing and longitudinal tension of the fast-growing Chinese ifr. The paperworks over the fire retardancy and bending of the China ifr to supply some theory basis andexperiences for the Development of Chinese&with multi functional and high strength.In the experiments of the study,the technics of wood impregnation is simple. Themodifiers contain ammonium polyphosphate, homemade&e-retardant? and the intermixtureliquid made of the homemade fire-retardant and the phenolic resin of low molecular weight? Detecting the performance of the homemade fire-retardant and the intermixture liquid made ofthe homemade fire-retardant and the phenolic resin of low molecular weight, and compare theseperformances of two modifiers. Yet, the thesis studies the changes of the treated ifr'sperformance. The results of whole thesis are as follow:The conclusions of the fire-retardant experiments are as follows:1)the oxygen index of all of these three modified woods is more than50%which is thestandard about fire-retardant index,all of these three modified woods have nice fire retardancy,What the best one is the wood treated by the intermixture liquid made of the homemadefire-retardant and the phenolic resin of low molecular weight which kept the most of it out ofburning atfer burning in20min is better than other two modified woods.In the loss-resistingconnection, the value of the wood treated by the intermixture liquid made of the homemadefire-retardant and the phenolic resin of low molecular weight is99.44%. In mechanical propertyconnection, the MOE of the wood treated by ammonium polyphosphate or the homemadefire-retardant is11%less than the untreated wood, But the MOE of the wood treated by theintermixture liquid made of the homemade fire-retardant and the phenolic resin of lowmolecular weight is35%more than the untreated wood,2)In the charirng rate experiment and the oxygen index expeirment, the expeirmentalresults of the homemade fire-retardant treated wood are close to the experimental results ofammonium polyphosphate treated wood.3)At the same case, the hygroscopicity of the modified woods can be sized down as: theammonium polyphosphate treated wood> the homemade fire-retardant treated wood> thewood treated by the intermixture liquid made of the homemade fire-retardant and the phenolicresin of low molecular weight. 4) In terms of ifre retardancy, mechanical property and loss-resisting, the properties of thewood treated by the intermixture liquid made of the homemade ifre-retardant and the phenolicresin of low molecular weight are better than the ammonium polyphosphate treated wood or thehomemade fire-retardant treated wood, so choosing the intermixture liquid made of thehomemade fire-retardant and the phenolic resin of low molecular weight as the modiifer usedthe bending of the Chinese ifr.The conclusions of the longitudinal compressing and longitudinal tension expeirments areas follows:1)The Plastic deformation of the wood increased atfer treated by impregnation, influenceof impregnation on strength still works,and the MOE of the impregnated wood is46.3%morethan the untreated wood.2)Boiling can influence the longitudinal compressing strength, the longitudinal tensionstrength, the strain, but not the yield stress.3)At the condition of wat°er temperature100C5the effect of sotfened is the best, andinfluence of the heat preserving time on the strength about the longitudinal compressing andlongitudinal tension is not enough.