Comprehensive Assessment Of Fast-grown-woods Pulping Properties

Wood characteristics of four fast-growing hard wood species, ( i.e. Populus×euranericana cL. '74/76', E. urophylla×grandis, Broussonetia papyrifere(1) vent and Salix×jiangsuensis cL."J799"), were investgated and analyzed, including fiber morphology, chemical composition, and basic density, major factors with significant impacts on kraft pulping properties; and their karft pulping properties investgated as well, including major physical, strength and optical properties. A predictive model (for PREDICATION of pulping properties from wood characteristics) was established with analyzing and statistic of datum available by literatures and our laboratory reports, by means of the SPSS12.0 multivariate statistical analysis system. This model was verified by the results of above four fast-grown hard wood samples, showing precious relations between predicated value and observed value. A comprehensive mult-indice pulping suitability evaluation model was established using fuzzy mathematics theory, based on the prediction and evaluation models, computer evaluation software were programmed.Wood characteristics results show that, the mean fiber length of tested wood smples could be classified into an ascent order, as E.urophylla×grandis, Populus×euranericana cL. '74/76', Broussonetia papyrifere(1)vent, Salix×jiangsuensis cL."J799"; and the order graduated with the L/D ratio as E.urophylla×grandis, Salix×jiangsuensis cL."J799"; Broussonetia papyrifere(1)vent, Salix×jiangsuensis cL."J799"; and that classified with wood basic density as E.urophylla×grandis, Salix×jiangsuensis cL."J799", Populus×euranericana cL. '74/76', Broussonetia papyrifere(1)vent. Considering chemical compositions of four tested wood samples, it is found that Salix×jiangsuensis cL."J799"seems to have excellent advantages in kraft pulping, because of higher content of holocellulose and lower contents of extractives and lignin, however, which are very sensitive factors on kraft pulping. If it is necessary to classify those four tested wood with their chemical compositions realted to kraft pulping, it might be listed as the followed line, E.urophylla×grandis > Broussonetia papyrifere(1)vent > Salix×jiangsuensis cL."J799"> Populus×euranericana cL. 74/76'. The study on pulping properties showed that strength properties of Salix×jiangsuensis cL."J799"such as burst index, tear index and tensile index arose with an increase in the drainability degree. In the same process conditions, comprehensive strength properties are best, tear index and tensile index best which separate going up to 9.2 mN·m2/g and 78.67 N·m/g at 40 oSR. The strength properties of Broussonetia papyrifere(1)vent is worst, tear index and tensile index separate 5.08 mN·m2/g and 65.34 N·m/g.Multiple nonlinear regressions were used to analyze the relativities of pulping yield and chemical composition, tensile index and tearing index and fiber morphology. The prediction model of pulping properties of fast growing woods has been established. The four fast-growing woods have been studied to verify forecasting models.Here, the letter"y"insteads of kraft pulping yield, %"x1"- Extractive content using alcohol benzene solution, %"x2"- Extractive content using 1% caustic soda solution,%"x3"- Extractive content using alcohol benzene solution,%"x4"- Lignin content, %"x5"- Cellulose content, %Here,"y"- Tensile index, N·m/g-1"x1"- Fibre length, mm"x2"- Fibre width, um"x3"- Basic density, g·cm-3Here,"y"- Tear index, mN.m2/g"x1"- Fibre length, mm"x2"- the L/D ratioRecorrelation coefficient shows that R separately is 0.978, 0.974, 0.964, and R2 0.956, 0.948, 0.928. Considering anova, critical number of yield is F0.05(5,4)=6.26,F0.01(5,4)=15.5,F=17.278> F0.05(5,4),F> F0.01(5,4),that of tensile index F0.05(5,4)=6.26,F0.01(5,4)=15.5,F=78.66783> F0.01(5,4)> F0.05(5,4), that of tear index F0.05(2,7)=4.74,F0.01(2,7)=9.55,F=45.390> F0.01(2,7)> F0.05(2,7),which shown that predicated value was fitting well with observed value, verified by the pulping properties of four fast-grown, while residualsε≤2, so the prediction models are feasible.A comprehensive mult-indice pulping suitability evaluation model was established using fuzzy mathematics theory. The contribution ratio of each parameter of main pulping properties could be worked out. Finally comprehensive evaluation model have been established to use, which is reliable after comparison.Delphi7+SQL2000 and SQL Server 2000 were used to stablishe comprehensive mult-indice pulping suitability evaluation system which mainly includes building up data-base of back-end, prediction and evaluation models, results inquire and report. The function concludes species information and kraft pulping properties of fast-grown woods, prediction and comprehensive evaluation of pulping properties and building data-base and method-base. The result certificate that this system satisfies manager's need and achieve the automation synthetical tasting purpose.