Study On The Impregnation Enhancement Of Trail Class Masson Pine And Chinese-fir Sheet

Trail class Masson Pine and Chinese-fir sheet impregnated with low molecular weightwater-soluble phenolic resin was studied in the paper. The main factors affect theimpregnation process, the resin filling modification of material, the surface wettability, theanti-corrosion performance and the different solid weight gain rate of resin on the properties ofMasson Pine and Chinese-fir were also analyzed. Resin distribution uniformity is the directfactor influencing the performances of modified materials. In order to use trail class MassonPine and Chinese-fir sheet effectively, this article explored a new kind of hot-pressingrestructuring. In addition, the balance time after the compression pressure on the impregnateduniformity of large length specimen was also studied. The results showed that:1, For Masson Pine, the degree of the influence on the impregnation effect was vacuum>pressure> normal pressure. For Chinese-fir, the degree of the influence on the impregnationeffect was pressure> vacuum> normal pressure. The influence of pressure was the least.“Vacuum and pressure” process is the best choice. Under the same impregnation process, theimpregnation effect of heart and sapwood was different. For Masson Pine, the impregnationeffect is good in heartwood. However, for Chinese-fir, the impregnation effect of sapwood isbetter than that of the heartwood.2, Low molecular weight PF resin was impregnated in the Masson Pine and Chinese-fir via“vacuum and pressure” process. Under the same impregnation process, the wet weight gain ofresin was same, but the solid resin weight gain rate increased with the increase of the resin solidcontent. In the thickness direction, the content of resin in the edge is more than that in theinside.3, After dealing with the different solid content of PF resin, the average density and sizestability of Masson Pine and Chinese-fir were increased with the increase of resin solid content.The modulus of rupture, the modulus of elasticity and hardness increased differently. However,the impact toughness decreased gradually with the increase of weight gain rate of resin.4, The resin was main filled in the lumen and intercellular space, cannot be seen clearly inthe cell wall. Resin just fill one part of the axial tracheid. The resin in the summerwood ofChinese-fir was more than that in the springwood. The contact angle of modified material wasmeasured by distilled water, anhydrous ethanol, glycerol, and diiodomethane four test reagentsand they were all larger than that of the material. With the increase of resin solid content,contact angle increased gradually. The consistent rule was that the contact angle of glycerol wasthe biggest and anhydrous ethanol was the smallest. By the method of two fluids, the surfacefree energy of modified material was greater than that of the material, and the material surfacefree energy was reduced with the increase of solid content of resin. After dealing with the PFresin, the corrosion levels of Masson Pine and Chinese-fir both increased respectively from Ⅲslightly corrosion and Ⅱ corrosion toⅠ strong corrosion.5、After being impregnated, the best technology of Masson Pine and Chinese-fir sheet weredealed with two layers of restructuring hot pressing was that put sheets in the hot press when the temperature was150℃, then press to rated pressure when the sheet internal temperaturereaches100℃, maintaining40minutes. Shut down the heat source and take out the sheet whenthe temperature dropped to100℃.6、After impregnated with the10%,20%,30%concentrations of PF resin, the dry wet shearstrength, wet shear strength and wood broken rate of sheet laminated material were higher thanthat of the material. The bond strength and wood broken rate of scrimber were increased withthe increase of concentrations of PF resin.7、Under the same impregnation process, the same thickness and width of the modifiedmaterial, When the specimen length is greater than a certain value, wet weight decreased withthe increase of the length of the specimen. When the specimen length is less than a certain value,wet weight gain rate remain unchanged. Under the same impregnation process and the samelength and width, wet weight decreased due to the increase of thickness. Under the same size,the wet weight of modified material increased with the increase of the pressure time.8、For Chinese-fir with the length of900mm, width is65mm, the balance time after theimpregnation affected the distribution of the resin in the modified material uniformity.Chinese-fir with the thickness of10mm and20mm need to balance two days or so. Theinternal resin can achieve static balance, and the resin distributed uniformity at the moment.