Abstract:

Three variaties of plantation poplar trees(Populus×euramericana cv.I-72/58,P.deltoides cv.I-63/51 and P.deltoides cv.I-69/55)growing in three different types of beaches along Yangtse River and in three different planting densities were extracted as the testing materials to model the relationships between wood properties and quality of veneer and plywood of poplar plantations in this study.Based on the relationships found in the former study,first the stepwise regression analysis was used for sifting out the key wood properties concerned,and then the polybasic,linear regression was used for modeling the relationships.The results show that the qualities of veneer and plywood of poplar plantations,can be well modeled with the wood properties by means of polybasic linear regression analysis.;The modeling equation of the variation of veneer thickness (VVT) varying with fiber width (FW) ,proportion of vessel (VP) and fiber (FP) is: VVT=-3.414+0.063FW+0.049RP-0.033VP The modeling equation of the ratio of lathe check (RLC) varying with wood hardness in tangential (TH), modules of elasticity (MOE) ,wood density in air-dry (WD) and volumetric shrinkage of wood in oven-dry (SV) is: RLC=9.472+0.005TH+0.003MOE+8.366WD-2.302SV The modeling equation of the gluing strength of plywood (GS) varying with pH values(pH),fiber length (FL) ,fiber width (FW) ,vessel length (VL) and proportion of vessel (VP) and ray (RP) is: GS=3.326-0.268 pH-0.002FL+0.191FW-0.004VL-0.033VP+0.095 RP The significances for the above modeling results were found greater than 0.73 while the relative error between the measured and predicted values was around 20%.Thus,the reliablity of those modeling equations could be recoglized.

Key words: Plantation poplar trees, Wood properties, Veneer and plywood, Modeling equations