Comparatively Study On Properties Of Pulping And Paper Of Juvenile And Mature Wood Of Populus Simonni×P.nigra

Rescently,the worst default of artificial forestry is that proportion of juvenile wood is higher than mature wood,and the period of felling between one time and next time on one tree is very short,so there are a lot of difference on the physical performance and chemical composition between juvenile wood and mature wood,and our aim of studying is how it will infect to properties of pulping and the physical performance of paper.Populus simonni×P.nigra was studied in this experiment,we studied the fiber performance and chemical composition,and looked for the best way of pulping of juvenile and mature wood by L₉(3⁴) orthogonality experiments,studied Kappa No.,yield,the properties of striking pulp,mixed the juvenile wood and mature wood with different proportion,and studied their properties of striking pulp with different round,and made paper from these pulp to measure out the physical performance of these paper.Finally,the basic status will be applied to factories in practice.The experiment showed:1.The content of benzene alcohol extractive of juvenile and mature wood respecfly is 2.05%and 1.43%,The content of lignin in juvenile wood and mature wood respectly is 20.82%and 19.57.the content of holocellulose is 50.52%and 47.65%,and the content of cellulose is 77.26%and 79.44%,on the level of 5%,the benzne alcohol extractive have notable difference,on the level of 10%,the contents of cellulose have notable difference, but lignin and holocellulose do not have notable difference.2.The fibre rate of length to width of Juvenile wood is 47.02,rankel ration is 0.39, The fibre rate of length to width of mature wood is 48.55,rankel ration is 0.45.3.With 5 different ways(NaOH+AQ,NaOH,KP,KP+S,KP+AQ) to make pulp,and study the pulp,the result showed that Kappa No.respectly is that 14.62,17.60,14.60, 14.35,14.19,and the yield is that 50.30%,48.00%,50.00%,50.10%,51.34%,so the best way is(KP+AQ).4.With L₉(3⁴) orthogonality experiments,range analysis and variance analysis,found that best progress is 16%use alkali amounts,60 min soaking,24%vulcanization degree, the Kappa No.and yield of juvenile wood respectly is 14.19 and 52.16%,and the mature wood respectly is 15.46 and 51.34%.5.The pulping fiber length of juvenile wood is shorter than that of juvenile,decreased about 2.53%,the ration of length and wideth decreased about 0.11.The pulping fiber length of mature wood is shorter,decreased about 5.95%,the ratio of length and wideth decreased about 1.53.6.Under the best technological conditions,studied the properties of pulping if different proportions of juvenile and mature wood mixture(1:2,1:3,1:4,1:5),found that with the proportion of mature wood increased,the Kappa No.will increase regularly too,but the yield decreased.7.The juvenile and mature wood was mixed with different rate to make pulp and strike pulp,under different rotation,the strike degree will ascend with the round increased, and will descend with the proportion of mature wood increased.8.The same proportion of juvenile wood and mature wood,the tearing index decrease with round ascending,when the same round,the index of bursting strength,tensile strength and elongation rate increased with the proportion of mature wood ascending.