Comparatively Study On Pulping Properties Of Reaction Zone And Opposite Zone In Masson Pine And Poplar

Reaction wood being defects inescapability in the physical machining process produces greater effects on the quality of product,from the view of pulping,so the pulping properties and paper properties of reaction wood,opposite wood and side wood were explored roundly and deeply in this thesis to prove whether they could achieve the request of making paper.Consequently,reasonable and efficient use of the timber could be realized and scientific theoretic basis could be offered.Because Masson pine and Poplar were often used for industrial material,they were regarded as researchful objects,the emphases of study were differences of properties between reaction wood and opposite wood.The results of research were as follows:1.Fiber Morphology and Chemical CompositionAverage fiber length of Masson pine(C,O,S) was respectively 3924μm,4025μm and 4220μm.From the results of fiber length,the pulping properties of compression zone were worse than that of opposite zone and side zone.But from the results of ratio of length to width and runkel ratio,the pulping properties of compression zone were better than that of opposite zone and side zone.Average fiber length of Poplar(T,O,S) was respectively 13211am,1227μm and 1171μm,they were bigger than that of some hardwood or other kinds Poplar.From the results of average fiber length and ratio of length to width,the pulping properties were the best in tension zone,but they were the worst in opposite zone.The content of lignin in compression zone of Masson pine was the highest;the contents of holocellulose and cellulose were the lowest.The content of lignin in tension zone of Poplar was the lowest,but the contents of holocellulose and cellulose were the highest in three zones.From the results of variance analysis and multiple comparisons,the effect of Masson pine(O,S,C) on lignin was more notable,and the difference between compression zone and opposite zone was larger.The effect on cellulose was very significant,and the difference between compression zone and opposite zone was also very significant. However,the effect on holoeellulose was not significant.The effect of Poplar(O,S,T) on lignin,holocellulose and cellulose were all very significant,and the difference between tension zone and opposite zone was also very significant. In conclusion,the three zones of Masson pine and Poplar were all suitable for pulping, and they were all better pulping material from the results of fibre morphology and chemical composition.2.Pulping PerformanceThe technologic conditions of orthogonal design were made out in compression zone and tension zone by groping test on three zones of Masson pine and Poplar.The best feasible conditions of pulping in three zones of Masson pine were made out by the results of orthogonal design of reaction zone.The results were as follows:active alkali,sulfidity and retention time of temperature were 20%,26%and 120minutes,respectively.The best feasible conditions of opposite zone in Poplar were as follows:active alkali, sulfidity and retention time of temperature were 16%,24%and 60minutes,respectively. And the best feasible conditions of tension zone and side zone were as follows:alkali, sulfidity and retention time of temperature were 14%,24%and 30minutes,respectively.Under the best feasible condition of pulping,kappa number and yield were respectively 23.13 and 45.18%in compression zone of Masson pine,which were higher than that of opposite zone and side zone.Kappa number and yield were respectively 9.70 and 61.03%in tension zone of Poplar,so kappa number was the lowest,however,the yield was the highest than that of opposite zone and side zone.3.Physical Performance of PaperWith the increase of active alkali,physical performances of paper in compression zone and side zone became worse.Under the condition of active alkali of 20%,several performances of paper in compression zone of Masson pine were all the worst in three zones.However,those of side zone were all the best.Under the condition of active alkali of 14%,index of tensile strength,index of bursting strength and index of synthetic strength in tension zone of Poplar were the smallest,only tear index was the biggest in three zones.In conclusion,compression zone and tension zone still presented definite defects in pulping;however,paper performances of opposite zone and side zone were better than reaction zone,so opposite zone and side zone could not only be made good use of pulping and making paper but also were regarded as better materials.