Study On Relationships And Models Between Wood Properties And Quality Of Pulp & Paper Of Normal Wood And Tension Wood In Poplar Plantation

Normal growth and eccentric growth poplar clone 107( Populus×euramericana cv. 'Neva') were selected for studying materials in this paper. At first, the radial variation pattern and trend of selected wood properties from both normal growth and eccentric growth poplar tree were concluded. Secondly, normal wood from normal growth poplar tree and tension wood from eccentric growth poplar tree were distinguished form other wood by combination stained method and "fuzzy appearance " method, and chopped out for determining wood chemical composition and ability f chemical pulp processing and quality of handsheet. Radial variation pattern and trend of chemical composition and quality of pulp and paper were also induced of both normal wood and tension wood. Furthermore, comparison of normal wood and tension wood of properties above was analyzed. Thirdly, according to the research result of radial variation of materials stated, relationship between wood properties and quality of pulp and paper were further analyzed, and Multiple Linear Regression method was utilized to establish experiential mathematic model for estimated pulp and paper qualities based on wood properties. Fourthly, surface longitudinal growth strain of standing tree and inner residual longitudinal growth strain of felled tree was determined at both normal growth and eccentric growth poplar clone 107 trees. Variation patterns and trends of different heights, different periphery positions and different radial positions were concluded. Furthermore, relationship between growth strain and tree growth characters and wood properties were analyzed. All results were listed as follows:1. Wood properties of normal wood of poplar clone 107According to anatomical properties of poplar clone 107, the clone was one of excellent materials for pulp and paper use. The result of radial variation showed: ray tissue proportion was increasing slowly from pith to bark, vessel tissue proportion was decreasing slightly outward, fiber tissue proportion was stable from pith since the fourth growth ring, and it was decreasing sharply later. Fiber length, fiber width, and ratio of fiber length to width were increasing from pith to outward firstly, and then keep stable when the each of them arrive a certain number. Runkel ratio was decreasing slowly at first, when it arrived at the fourth growth ring, the value of Runkel ratio increasing sharply outward. The shape of general variation trend of microfibrill angle was similar to parabola with downward opening, and the maximum located at the fourth growth ring. ANOVA shown that fiber morphological characters were significant varied among different tress and different growth rings, and the level of significant was different among different characters. Effect of growth ring on vessel tissue proportion and fiber tissue proportion was significant, when it comes to ray tissue proportion, the result was insignificant.According to wood chemical composition, poplar clone was also considered as a excellent materials for pulp and paper use. The radial variation trend of each chemical component was induced, and it listed as follows. Cellulose content and a-cellulose content was increasing from pith to outside. And, it kept stable at the sixth growth ring later. The trend curve of holo-cellulose and 1 % sodium hydroxide extractives content is similar to a parabola with downward opening, and the maximum is at the fifth growth ring. Benzene-alcohol extractives content is decreasing from pith to bark. The general radial trend of wood crystallinity formed a parabola with downward opening, and the maximum data located between the fifth growth ring and sixth growth ring. The variance analysis suggested that individual tree and growth ring affected wood chemical component significantly. Oven dry wood density of poplar clone 107 was relative lower than other poplar clones, and it means poplar clone 107 is more suitable for pulp and paper use. The radial variation trend of oven dry wood density formed a parabola with upward opening. The effect of individual tree and growth ring on oven dry wood density was significant.Growth strain of poplar clone 107 also was determined and the variation pattern and trend at different height, different periphery position was analyzed. The result indicated that surface growth strain from different periphery position varied insignificantly, however, it difference among different height was apparent. Double cell wall width of fiber and longitudinal shrinkage was deceased when the growth tensile growth increasing. The general radial variation trend curve of inner residue longitudinal growth strain was similar to parabola with downward opening, and the maximum of strain located at the pith.2. Wood properties of tension wood of poplar clone 107Distribution of tension wood among different trees and different growth ring was greatly uneven. Comparison of fiber length, fiber width, and the ratio of fiber length to fiber width, and ray tissue proportion was absurd, but, normal wood had bigger microfibril angle and vessel tissue proportion than tension wood, and tension wood had advantage at double width of cell wall and Runkel ratio, and the difference was significant at several different levels. Radial variation of anatomical properties both at tension wood zone and opposite wood zone of eccentric growth poplar clone 107 tree were concluded. The ray tissue proportion was deceasing at a certain speed at tension wood zone, and vessel tissue proportion was growing from pith to bark at same zone. Fiber tissue proportion kept stable between pith to the fourth growth increments, and deceased slightly later at tension wood zone. Fiber length both from tension wood zone and opposite wood zone were generally increasing from pith to outward, and fiber width, Runkel ratio, and double cell wall width also hold same trend at tension wood zone, but the variation trend curve was more plane. Diameter of lumen kept at same lever from the first growth ring to the fourth, and deceased later at tension wood zone. Radial variation trend curve of ratio of fiber length to fiber width at tension woo zone was like a parabola with downward opening, and the maximum of vlaue located at the fourth growth ring. At tension wood zone, microfibril angle was decreasing from pith to bark, however, it radial trend curve at opposite wood was similar to ratio of fiber length to fiber width's curve. Degree of difference of several anatomical properties among different trees and different growth increments varied slightly. Fiber length, fiber width, double cell wall width, microfibrill angle and diameter of lumen were significantly varied among trees and growth rings, however the comparison of ratio of fiber length to fiber width was unapparent. Only fiber tissue proportion of all tissue proportion was significantly varied among trees and growth rings.Tension wood had dramatically higher cellulose content, a-cellulose content than normal wood, and wood crystallinity was little higher than normal wood. So, normal wood had higher lignin content and 1% sodium hydroxide extractives content than tension wood accordingly. When it came to holo-cellulose content, it is quite similar between two different wood types. The effect of individual tree and growth increment on wood chemical composition and wood crystallinity was significant. Tension wood had higher oven dry wood density than normal wood, and the wood density at tension wood zone held at same level between pith and the fourth growth ring, and then increased sharply. Variance analysis also suggested that oven dry wood density varied significantly among different trees and growth increments.Tensile growth stress mainly existed at periphery of eccentric growth poplar tree, and the maximum value located at the upper side of leaned tree or protuberant side of bended tree. The tensile growth stress was decreasing from the upper side to lower side or from protuberant side to concave side, and even compressive growth stress was detected at lower side of leaned tree or protuberant side of bended tree. Furthermore, the comparison of growth stress among different trees and different periphery positions were significant. However, different height of some tree had not significant effect on growth stress. The relationship between surface longitudinal growth stress of living tree and wood characters was analyzed, and the result shown that double cell wall width, Runkel ration, oven dry longitudinal shrinkage, oven dry radial shrinkage, and tangential shrinkage was increased when the tensile growth stress was growing. Fiber width and diameter of lumen was decreased conversely. Radial trend of inner residual longitudinal growth strain of fallen log of eccentric growth poplar tree formed parabola with upward opening, and the summit situated at pith. From scatted doc diagram, the growth strain at tension wood zone was lower than opposite wood zone at their outmost growth ring, and that indicated that tensile growth stress at periphery of tension wood zone was higher than it at corresponding position of opposite wood zone.3. Quality of pulp and paper both of normal wood and tension wood of poplar clone 107Compare with other poplar clone, the ability of chemical pulp processing of normal wood poplar clone 107 situated at middle level. Pulp yield was increasing from pith to outward at first, and slightly deceasing at the sixth growth ring. Radial trend curve is similar to parabola with upward opening, the minimum value located at the fourth growth ring. Based on radial variation pattern of selected wood properties and chemical pulpability of normal wood, it was suggested that the rotation age of poplar clone 107 tree should more than 6 years for more pulp yield and better quality of pulp. Effect of individual tree on pulp yield was insignificant, but significant effect was found on kappa value. Pulp yield significant varied among different growth ring, however, the same significance had not found for kappa value.Tensile strength index of normal wood handsheet had a general radial variation trend curve, and it was like a downward opening parabola which summit located at the fourth growth ring. Tear strength index was increasing from pith to the third growth ring, and then kept stable for several rings, and was increasing quickly since the fifth growth ring at last. Radial variation trend of bursting strength index formed a parabola with downward opening shape, and the summit located at the fifth growth ring. Based on general variation pattern and trend of paper quality related wood properties and paper quality itself, it was suggested that the rotation age of poplar clone 107 tree should shorter than 5years for obtaining high quality paper. Combining suggestion from pulpability research and from handsheet quality research, the general conclusion of prime rotation age of poplar clone 107 tree was six years or seven years according to researching result of this paper. Growth ring significant affected all three quality index of handsheet. However, when it came to individual tree, tensile strength index and tear strength index was still hold the significance, but difference of bursting strength index among trees was unapparent.Tension wood had higher pulp yield and lower kappa value than normal wood. Both difference of pulp yield and kappa value among trees were insignificant. The effect of growth ring on pulp yield was significant, but kappa value was not same. Normal wood was higher than tension wood at tensile strength index and Bursting strength index, and the tear strength index was quite same between two different woods. All three paper quality index significant varied among different trees, and also among different growth rings except for bursting strength index. Along with increasing of stirring revolution, the freeness of pulp of tension wood was decreasing continuously, and tensile strength index of tension wood handsheet was increasing sharply at first few levels and then kept stable. Under the same circumference, tear strength index of tension wood handsheet was improved at first and was decreasing later. Bursting strength index of tension wood handsheet was increasing continuously. After 12000 revolutions stirring, tensile strength index and Bursting strength index of tension wood paper was improved to same level of paper of normal wood, however, tension wood still had lower quality of paper than normal wood comprehensively. In addition, the improvement of quality of tension wood paper had a upper limit, because more revolution is harmful to quality of paper.4. Modeling relationship between wood properties and pulpability and quality of paper both of normal wood and tension wood.The result of research of correlation and partial correlation (control growth ring, the follow is same) between selected wood properties and wood pulpability of normal wood shown that pulp yield was significant positive correlated with holo-celluslose content (Χ₁) , cellulose content(Χ₃), a-cellulose content (Χ₄), wood crystanillity (Χ₈), 1% sodium hydroxide extractives content(Χ₆), and significant negative correlation or partial correlation were found between pulp yield and benzene-alcohol extractives content (Χ₇, oven dry wood density(Χ₉). There are no apparent correlation or partial correlation were detected between pulp yield and semi-cellulose content (Χ₂) and ray tissue proportion (Χ10). Positive correlations were found between Kappa value and lignin content(Χ₅), oven dry wood density, vessel tissue proportion (Χ₁₁) , and conversely correlations were found between Kappa value and fiber tissue proportion. The result of research of correlation and partial correlation (control growth ring, the follow is same) between selected wood properties and wood pulpability of tension wood shown that pulp yield was significant positive correlated with holo-celluslose content, cellulose content, a-cellulose content, wood crystanillity, oven dry wood density, fiber tissue proportion, and significant negative correlation or partial correlation were found between pulp yield and benzene-alcohol extractives content, 1% sodium hydroxide extractives content, lignin content. There are no significant correlation was found between Kappa value and selected wood properties except negative correlation with a-cellulose content.Principal component analysis was utilized for reducing number of selected wood properties. When the first few principal components were extracted, multiple liner regression was implemented for modeling relationship between wood pulpability and extracted principal components. Whereafter, the liner regression model between selected wood properties and wood pulpability was established by further calculation. The liner evaluation model for pulp yield and kappa value based on selected wood quality was listed as follows:Model of normal woodPulp·yield =0.615χ₁-0.583χ₂+1.23χ₃+1.203χ₄-0.380χ₅+1.380χ₆-0.357χ₇+0.790χ₈-0.050χ₉-0.231χ₁₀+0.139χ₁₁+0.074χ₁₂+140.438(**)Kappa·value =0.146χ₁-0.292χ₂ +0.095χ₃ +0.114χ₄ +0.620χ₅ -0.398χ₆ -0.106χ₇ +0.017χ₈+0.070χ₉-0.022χ₁₀+0.890χ₁₁-0.670χ₁₂+17.962 (ns)Model of tension woodPulp·yield =0.1924χ₁-0.5096χ₂ +2.5002χ₃ +4.2296χ₄ -0.7326χ₅ +1.0323χ₆ -.010 54χ₇+1.8616χ₈+0.021χ₉-0.1664χ₁₀-08759χ₁₁+1.0424χ₁₂+163.9981(***) Kappa·value =1.2136χ₁ +0.0784χ₂-1.2501χ₃ -2.5502χ₄ +0.4884χ₅ +0.2997χ₆-0.062χ₇-1.074χ₈-0.008χ₉+0.1976χ₁₀+0.5968χ₁₁-0.7923χ₁₂+23.1694 (ns)Comprehensive Model of all woodPulp·yield =2.703χ₁-1.880χ₂+5.846χ₃ +5.085χ₄-2.3912χ₅ -0.108χ₆-0.632χ₇ +3.177χ₈-0.019χ₉ -0.191χ₁₀+2.415χ₁₁+0.678χ₁₂-100.4062(***)Kappa·value =-0.5456χ₁+3.3528χ₂-3.7χ₃ -3.1188χ₄+2.2736χ₅+1.3283χ₆+0.144χ₇-1.9228χ₈-0.016χ₉-0.371χ₁₀+1.6744χ₁₁-1.1951χ₁₂-100.4062(***)The result of research of correlation and partial correlation (control growth ring, the follow is same) between selected wood properties and quality of paper of normal wood shown that positive significant correlation was found between tensile strength index with fiber length (Χ₁), fiber width (Χ₂), ratio of fiber length to fiber width(Χ₃), diameter of lumen(Χ₄), fiber tissue proportion(Χ₁₀), wood crystanillity(Χ₁₁), and negative significant correlation with oven dry wood density(Χ₁₂), double cell wall width(Χ₅), Runkel ratio(Χ₆), vessel tissue proportion(Χ₉), and there were no significant correlation with mcirofibrill angle(Χ₇), ray tissue proportion(Χ₈). Significant positive correlations were found between bursting strength index and fiber width, and diameter of lumen, and significant negative correlation were found between double cell wall width and Runkel ratio. Tear strength index significant positive correlated with double cell wall width, fiber length, ratio of fiber length to fiber width, Runkel ratio, and oven dry wood density. Because of uneven distribution of tension wood among different tree and different growth, the correlation between wood quality and quality of paper was insignificant, so, the liner regression model had not calculated at this paper.The liner evaluation model for three quality index of paper based on selected wood quality was listed as follows:Model of normal wood:Tensile·strength-index =340.524χ₁ +2.037χ₂ +10.627χ₃+1.714χ₄ +0-109χ₅ -0.011χ₆-0.311χ₇+2.794χ₈-3.864χ₉+3.993χ₁₀+1.260χ₁₁-0.0313χ₁₂+2288.786(**)Tear·strength·index =57.962χ₁ +0.244χ₂ +1.837χ₃ -0.071χ₄ +0.258χ₅ +0.018χ₆ -1.246χ₇+0.121χ₈-0.222χ₉+0.099χ₁₀+0.034χ₁₁+0.913χ₁₂+355.325(**)Bursting·strength·index =1359.080χ₁+8.259χ₂+41.131χ₃+8.366χ₄-0.707χ₅-0.158χ₆+11.176χ₇-4.422χ₈-7.256χ₉+11.061χ₁₀+7.039χ₁₁-0.136χ₁₂+8643.946(ns)Comprehensive model of all wood:Tensile·strength·index =0.184χ₁ +0.056χ₂ +0.122χ₃ +0.257χ₄ -0.212χ₅ -0.218χ₆+0.054χ₇ -0.067χ₈ -0.080χ₉ +0.097χ₁₀ -0.154χ₁₁ -0.099χ₁₂ +74.046(***)Tear·strength·index =0.140χ₁+0.097χ₂+0.105χ₃ -0.004χ₄ +0.079χ₅ +0.039χ₆ +0.034χ₇+0.060χ₈+0.024χ₉-0.213χ₁₀+0.055χ₁₁+0.014χ₁₂+10.987(*)Bursting·strength ? index =0.100χ₁ -0159χ₂ +0.042χ₃ +0.238χ₄ -0.202χ₅ -0.210χ₆+0.073χ₇-0.042χ₈-0.046χ₉ +0.057χ₁₀ -0.156χ₁₁ -0.139χ₁₂ +451.240(***)...