Effects of loblolly pine tree age and wood properties on linerboard-grade pulp yield and sheet properties: Part 2

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 41-50
Author(s):  
THOMAS J. MCDONOUGH ◽  
CHARLES E. COURCHENE ◽  
DAVID E. WHITE ◽  
LAURENCE SCHIMLECK ◽  
GARY PETER

Results are presented on the relationships among loblolly pine tree age and wood characteristics and the properties of pulp obtained when the trees were chipped and pulped. We selected 13-year-old and 22-year-old loblolly pine trees (18 of each) to represent specified ranges of specific gravity and lignin content. The trees were further characterized by chemical analysis, near infrared (NIR) spectroscopy, and SilviScan analysis of fiber dimensions and properties before being pulped by the kraft process. Handsheets formed from the resulting pulps were characterized in terms of sheet properties that are important for linerboard grades. Multiple regression analysis was then used to identify wood characteristics that most influenced sheet properties and to derive equations relating sheet properties to tree age, specific gravity, and chemical composition. We also developed calibrations so that sheet properties could be predicted from NIR spectroscopic analysis of wood. Nearly all differences in properties of pulps made from 13- and 22-year-old trees were attributable to differences in fundamental wood properties. Sheet properties could be estimated by measuring their near NIR spectra.

TAPPI Journal ◽  
2011 ◽  
Vol 10 (9) ◽  
pp. 45-53 ◽  
Author(s):  
T.J. MCDONOUGH ◽  
C.E. COURCHENE ◽  
D.E. WHITE ◽  
L. SCHIMLECK ◽  
G. PETER

Results are reported on the relationships of loblolly pine tree age and wood characteristics and the yield of pulp obtained when the trees were chipped and pulped by the kraft process. Eighteen 13-year old and 18 22-year-old loblolly pine trees were selected to represent specified ranges of specific gravity and lignin content. The trees were further characterized by chemical analysis and near infrared spectroscopy before kraft pulping. The resulting pulps were characterized by measurements of yield and chemical analysis. Multiple regression analysis was used to identify wood characteristics that most influenced pulp yield and to derive equations relating pulp yield to tree age, specific gravity, and wood chemical composition. In addition, near-infrared spectroscopy calibrations were developed to allow prediction of pulp yield from analysis of wood. The results showed that wood specific gravity cannot be used to predict the yield of linerboard-grade pulp from trees of either age. The yield of pulp from 13-year-old trees can be predicted from the amounts of xylan and lignin present in the wood. The yield of pulp from 22-year-old trees decreased with increasing lignin content but was unrelated to xylan content. Thirteen-year-old trees had significantly higher xylan content and the excess xylan was lost during pulping. Regression equations were developed for estimating pulp yields from 13- and 22-year-old trees, given their xylan and lignin contents. Another equation derived from the combined data for trees of both age classes will be useful for predicting yields from trees of other ages, if it is assumed that the effect of tree age is linear.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (4) ◽  
pp. 31-36 ◽  
Author(s):  
DAVID E. WHITE ◽  
CHARLES COURCHENE ◽  
THOMAS MCDONOUGH ◽  
LAURIE SCHIMLECK ◽  
DAVID JONES ◽  
...  

We quantified the effects of wood density (chip specific gravity) and wood chemical composition (cellulose, hemicellulose, and lignin) on the kraft pulp yield of 13-year-old loblolly pine trees (Pinus taeda) grown as part of a genetic selection study. Both bleachable (kappa No. 30) and linerboard grade (kappa No. 100) pulps were made from 18 trees selected for combinations of wood specific gravity and cellulose:hemicellulose:lignin ratios. Statistical analysis indicated that digester pulp yield correlated significantly with wood xylan content and cellulose-to-lignin ratio but was not strongly correlated to wood specific gravity. Near infrared (NIR) spectra were collected from wood samples and correlated with the total kraft pulp yields. The analyses for both kappa No. 30 and kappa No. 100 pulps provided strong calibration statistics, suggesting that papermakers can use NIR spectroscopy to esti-mate the bleachable and linerboard grade pulp yields of P. taeda whole-tree samples.


2005 ◽  
Vol 35 (10) ◽  
pp. 2423-2431 ◽  
Author(s):  
Robert Sykes ◽  
Bailian Li ◽  
Gary Hodge ◽  
Barry Goldfarb ◽  
John Kadla ◽  
...  

Near-infrared (NIR) spectroscopy is a rapid nondestructive technique that has been used to characterize chemical and physical properties of a wide range of materials. In this study, transmittance NIR spectra from thin wood wafers cut from increment cores were used to develop calibration models for the estimation of α-cellulose content, average fiber length, fiber coarseness, and lignin content in the laboratory. Eleven-year-old trees from two sites were sampled using 12-mm increment cores. Earlywood and latewood of ring 3 and ring 8 from these samples were analyzed in the laboratory using microanalytical methods for α-cellulose content, average fiber length, fiber coarseness, and lignin content. NIR calibrations and laboratory measurements based on one site were generally reliable, with coefficients of determination (R2) ranging from 0.54 to 0.88 for average fiber length and α-cellulose content, respectively. Predicting ring 8 properties using ring 3 calibration equations showed potential for predicting α-cellulose content and fiber coarseness, with R2 values of approximately 0.60, indicating the potential for early selection. Predicting the wood properties using the calibration equations from one site to predict another showed moderate success for α-cellulose content (R2 = 0.64) and fiber coarseness (R2 = 0.63), but predictions for fiber length were relatively poor (R2 = 0.43). Prediction of lignin content using transmittance NIR spectroscopy was not as reliable in this study, partially because of low variation in lignin content in these wood samples and large errors in measuring lignin content in the laboratory.


2005 ◽  
Vol 35 (1) ◽  
pp. 85-92 ◽  
Author(s):  
P D Jones ◽  
L R Schimleck ◽  
G F Peter ◽  
R F Daniels ◽  
A Clark III

Preliminary studies based on small sample sets show that near infrared (NIR) spectroscopy has the potential for rapidly estimating many important wood properties. However, if NIR is to be used operationally, then calibrations using several hundred samples from a wide variety of growing conditions need to be developed and their performance tested on samples from new populations. In this study, 120 Pinus taeda L. (loblolly pine) radial strips (cut from increment cores) representing 15 different sites from three physiographic regions in Georgia (USA) were characterized in terms of air-dry density, microfibril angle (MFA), and stiffness. NIR spectra were collected in 10-mm increments from the radial longitudinal surface of each strip and split into calibration (nine sites, 729 spectra) and prediction sets (six sites, 225 spectra). Calibrations were developed using untreated and mathematically treated (first and second derivative and multiplicative scatter correction) spectra. Strong correlations were obtained for all properties, the strongest R2 values being 0.83 (density), 0.90 (MFA), and 0.93 (stiffness). When applied to the test set, good relationships were obtained (Rp2 ranged from 0.80 to 0.90), but the accuracy of predictions varied depending on math treatment. The addition of a small number of cores from the prediction set (one core per new site) to the calibration set improved the accuracy of predictions and importantly minimized the differences obtained with the various math treatments. These results suggest that density, MFA, and stiffness can be estimated by NIR with sufficient accuracy to be used in operational settings.


2003 ◽  
Vol 33 (12) ◽  
pp. 2297-2305 ◽  
Author(s):  
L R Schimleck ◽  
C Mora ◽  
R F Daniels

The application of near infrared (NIR) spectroscopy to the green wood of radial samples (simulated increment cores) and the development of calibrations for the prediction of wood properties are described. Twenty Pinus taeda L. (loblolly pine) radial strips were characterized in terms of air-dry density, microfibril angle (MFA), and stiffness. NIR spectra were obtained in 10-mm steps from the radial longitudinal and transverse faces of each sample and used to develop calibrations for each property. NIR spectra were collected when the wood was green (moisture content ranged from approximately 100% to 154%) and dried to approximately 7% moisture content. Relationships between measured and NIR estimates for green wood were good; coefficients of determination (R2) ranged from 0.79 (MFA) to 0.85 (air-dry density). Differences between calibrations developed using the radial longitudinal and transverse faces were small. Calibrations were tested on an independent set. Predictive errors were relatively large for some green samples and relationships were moderate; R2p ranged from 0.67 (MFA) to 0.81 (stiffness). Dry wood calibrations demonstrated strong predictive relationships with R2p ranging from 0.87 (air-dry density) to 0.95 (stiffness). NIR spectroscopy has the potential to predict the air-dry density, MFA, and stiffness of 10-mm sections of green P. taeda wood samples.


2020 ◽  
Vol 21 (6) ◽  
Author(s):  
Gudiwidayanto Sapto Putro ◽  
Sri Nugroho Marsoem ◽  
Joko Sulistyo ◽  
Suryo Hardiwinoto

Abstract. Putro GS, Marsoem SN, Sulistyo J, Hardiwinoto S. 2020. The growth of three teak (Tectona grandis) clones and its effect on wood properties. Biodiversitas 21: 2814-2820. Various clones of superior teak (Tectona grandis L. f.) trees have recently been introduced in several land conditions. A study was conducted on three different clones of superior teak known as Jati Unggul Nusantara (JUN) growing in Paliyan, Gunungkidul, Yogyakarta, Indonesia. Two different ages of those clones were observed their growth rate and its wood properties. Strip plot design was applied to the treatment of tree age (five and eight-year-old) and clone types (D14, F35, and F21 clones). Tree growth was measured on 300 trees, meanwhile, annual growth rate and wood properties were measured on 18 trees. The result showed that at five-year-old as well as eight-year-old, the D14 clone has the best growth performance with diameter of 14.6 ± 1.80 cm and 20.5 ± 2.54 cm and height of 9.8 ± 1.72 m and 15.2 ± 2.13 m respectively. The growth rate negatively correlated with temperature and had no significant correlation to the precipitation. Different clones and tree age significantly affect the variability of fiber length, green specific gravity, and heartwood proportion. The clone of D14 produced the highest-fiber length, green specific gravity, and heartwood proportion (1.111mm; 0.50 and17.7%) at five-year-old trees and (1.156 mm; 0.54 and 49.0%) at eight-years-old.


2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Laurence R. Schimleck ◽  
Finto Antony ◽  
Christian Mora ◽  
Joseph Dahlen

AbstractWe examined the within-tree variation of pulp yield and lignin content for loblolly pine (Pinus taeda L.) trees aged 13 and 22 years. Radial trends in pulp yield (increase) and lignin (decrease) were consistent with what would be expected for loblolly pine as were changes in properties related to maturation. Maps, based on the average of 18 trees at each age, depicting pulp yield variation within-tree were similar to loblolly pine maps reported for microfibril angle and stiffness, while lignin maps resembled the inverse of those reported for density and related properties. Mixed-effects models for both properties were developed with the base model for pulp yield explaining 64% of the observed variation, with the inclusion of tree height improving the model slightly, whereas models for lignin content explained 44% of the variability. The models could be incorporated into growth and yield prediction systems, or procurement model systems that predict within-tree wood properties based on age and tree size.


TAPPI Journal ◽  
2011 ◽  
Vol 10 (2) ◽  
pp. 36-42 ◽  
Author(s):  
DAVID E. WHITE ◽  
CHARLES COURCHENE ◽  
THOMAS MCDONOUGH ◽  
LAURIE SCHIMLECK ◽  
GARY PETER ◽  
...  

The effects of wood properties on the strength of bleachable and linerboard grade kraft pulps from 13-year-old loblolly pine (Pinus taeda) trees were investigated. Eighteen trees were selected based on breast height wood cores to represent specified ranges of specific gravity and lignin content. Air-dry density and stiffness (modulus of elasticity [MOE]), tracheid coarseness, radial diameter, tangential diameter, specific surface area, wall thickness, and microfibril angle (MFA) were estimated using SilviScan wood analysis technology and near infrared reflectance (NIR) spectroscopy. NIR spectra collected in 10 mm sections from the surface radial strips correlated very well with air-dry density, MFA, MOE, and tracheid wall thickness and were used to develop whole tree predictions. In addition, chemical composition, fiber properties, and handsheet strength were measured for both pulp grades. Statistical analysis indicated that wood density, wood fiber coarseness, and pulp fiber length had the greatest effects on sheet properties.


1998 ◽  
Vol 6 (A) ◽  
pp. A117-A123 ◽  
Author(s):  
L. R. Schimleck ◽  
A. J. Michell ◽  
C. A. Raymond ◽  
A. Muneri

In Australia, considerable effort has been directed at improving the pulp yield of plantation grown trees through tree breeding programs. However, an improvement in pulp yield relies on the assessment of large numbers of trees. Traditional methods of assessment are expensive, time consuming and destructive, inhibiting their use. Cores can be extracted non-destructively from standing trees using TRECOR, a handheld motor driven drill. The cores are milled, their near-infrared spectra obtained and pulp yield estimated using an appropriate calibration model. The height at which the core is taken is very important. It must represent the whole tree and sampling must be easy and practical. The longitudinal and radial (within-tree) variation of pulp yield for 15 Eucalyptus nitens trees was examined using near-infrared (NIR) spectroscopy. The trees were taken from three families (five trees per family) selected for giving high, medium and low pulp yields respectively. Three trees (one from each family) were examined in detail. Maps of within-tree variation of pulp yield were developed. Pulp yield was found to be highly variable within individual trees and between trees of the same family. The yield of samples from 10% of tree height (approximately 2.2 m) gave the best correlation with whole-tree yield. Samples from 5% of tree height (approximately 1.1 m) gave a slightly lower correlation but provided a more convenient sampling height. Ten Eucalyptus globulus and ten E. nitens trees growing on five sites in Australia were used to examine the longitudinal variation of pulp yield. Trees from sites in Tasmania, Western Australia and Victoria were sampled. The optimal sampling height for E. globulus was 1.1 m. No single sampling height could be recommended for E. nitens due to large site effects.


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