Papermaking properties of the ECF-bleached kraft pulps from first-thinning Scots pine (Pinus sylvestris L.)

Holzforschung ◽  
2007 ◽  
Vol 61 (1) ◽  
pp. 8-13 ◽  
Author(s):  
Riikka Rautiainen ◽  
Raimo Alén
Keyword(s):  
Optical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Outer Part ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Kraft Pulps ◽  
Stem Wood ◽  
Softwood Kraft Pulp ◽  
Long Fibers

Abstract First-thinning Scots pine (Pinus sylvestris) and the outer (containing long fibers) and inner (containing short fibers) parts of its stem wood were delignified on a laboratory scale by kraft pulping followed by oxygen-alkali delignification and bleaching with D0(EO)D1(EP)D2. The aim was to evaluate the potential use of the bleached pulps as reinforcing material in various mechanical and chemical pulps. The physical and optical properties of the pulps indicated that only the “outer part pulp”, with rather similar properties to those of a reference softwood kraft pulp, seemed suitable for this purpose. In contrast, materials from first-thinning stem wood and its inner part resulted in lower yields as early as the kraft pulping stage. Rather mediocre strength properties were obtained, but the bleached kraft pulps prepared from the two first thinning-based materials had good optical properties.

Characterization of black liquors from kraft pulping of first-thinning Scots pine (Pinus sylvestris L.)

Holzforschung ◽  
2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Riikka Rautiainen ◽  
Raimo Alén
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Black Liquor ◽  
Outer Part ◽  
Short Fiber ◽  
Kraft Pulping ◽  
Hydroxy Acids ◽  
Stem Wood ◽  
Black Liquors ◽  
Average Molecular Masses

Abstract Formation of hydroxy acids and soluble lignin fragments was investigated during conventional kraft pulping of first-thinning Scots pine (Pinus sylvestris L.) stem wood and its long-fiber outer part and short-fiber inner part. The results indicate that there are characteristic differences in the formation of hydroxy acids in these specific tissues, due to the slightly different contents of cellulose, hemicelluloses, and lignin. Notable are the differences in the formation of xylan-derived acids (2-hydroxybutanoic and xyloisosaccharinic acids) and glucomannan- and cellulose-derived acids (3,4-dideoxy-pentonic and glucoisosaccharinic acids). In contrast, no significant differences were found in the average molecular masses of the dissolved lignins in these black liquors. Finally, the black liquor from the outer part of first-thinning pine was shown to have similar properties as the black liquor from the reference mature wood material.

Strength properties of wind- and snow-damaged stems of Picea sitchensis and Pinus sylvestris in comparison with undamaged trees

1999 ◽  
Vol 29 (5) ◽  
pp. 595-599 ◽  
Author(s):  
A D Cameron ◽  
R A Dunham
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Compression Wood ◽  
Outer Part ◽  
Sitka Spruce ◽  
Strength Properties ◽  
Picea Sitchensis ◽  
Modulus Of Rupture ◽  
Clear Wood ◽  
Pine Trees

This study compared the strength properties of wood taken from Sitka spruce (Picea sitchensis (Bong.) Carr.) and Scots pine (Pinus sylvestris L.) trees damaged as a result of wind and snow. The spruce trees were located in triplets of stems of similar diameter that had snapped, overturned (i.e., uprooted), or remained undamaged as a result of wind and snow. The pine trees were located in pairs of similar-sized stems that had snapped or remained undamaged. None of the pine trees overturned. Clear wood (wood without knots and sloping grain) from the outer part of the stem of snapped Sitka spruce and Scots pine trees was less stiff (lower modulus of elasticity (MOE)) than wood taken from the same location from overturned (spruce only) or standing trees. Modulus of rupture and density were unaffected. Damaged trees of both species were found to have significantly more compression wood within the test samples in comparison with undamaged trees. These findings suggest that trees that either overturn or snap are bending more than undamaged trees (because of their low MOE) thereby introducing a greater component of crown weight to the overall forces acting on the stem, and that this may be associated with compression wood.

scholarly journals Chemical characteristics and Kraft pulping of tension wood from Eucalyptus globulus labill

2012 ◽  
Vol 36 (6) ◽  
pp. 1163-1172 ◽  
Author(s):  
María Graciela Aguayo ◽  
Regis Teixeira Mendonça ◽  
Paulina Martínez ◽  
Jaime Rodríguez ◽  
Miguel Pereira
Keyword(s):  
Eucalyptus Globulus ◽  
Lignin Content ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Pulp Yield ◽  
Chemical Characteristics ◽  
Kraft Pulps ◽  
Opposite Wood ◽  
Alkali Consumption ◽  
Pulp Strength

Tension (TW) and opposite wood (OW) of Eucalyptus globulus trees were analyzed for its chemical characteristics and Kraft pulp production. Lignin content was 16% lower and contained 32% more syringyl units in TW than in OW. The increase in syringyl units favoured the formation of β-O-4 bonds that was also higher in TW than in OW (84% vs. 64%, respectively). The effect of these wood features was evaluated in the production of Kraft pulps from both types of wood. At kappa number 16, Kraft pulps obtained from TW demanded less active alkali in delignification and presented slightly higher or similar pulp yield than pulps made with OW. Fiber length, coarseness and intrinsic viscosity were also higher in tension than in opposite pulps. When pulps where refined to 30°SR, TW pulps needed 18% more revolutions in the PFI mill to achieve the same beating degree than OW pulps. Strength properties (tensile, tear and burst indexes) were slightly higher or similar in tension as compared with opposite wood pulps. After an OD0(EO)D1 bleaching sequence, both pulps achieved up to 89% ISO brightness. Bleached pulps from TW presented higher viscosity and low amount of hexenuronic acids than pulps from OW. Results showed that TW presented high xylans and low lignin content that caused a decrease in alkali consumption, increase pulp strength properties and similar bleaching performance as compared with pulps from OW.

Evaluation of beetle-killed white spruce for pulp and paper

1983 ◽  
Vol 13 (2) ◽  
pp. 246-250 ◽  
Author(s):  
Richard A. Werner ◽  
Erwin E. Elert ◽  
Edward H. Holsten
Keyword(s):  
White Spruce ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Pulp Yield ◽  
Kraft Pulps ◽  
High Quality ◽  
South Central ◽  
Dead Trees ◽  
Standing Trees ◽  
First Results

A kraft pulping study on standing white spruce (Piceaglauca (Moench) Voss) killed by spruce beetles (Dendroetonusrufipennis (Kirby)) in south central Alaska showed no difference in pulp yield between trees dead for 1 year and those dead for as long as 50 years. Strength properties of beetle-killed white spruce remained extremely high in all dead trees regardless of how long they had been dead, so they apparently could be used for producing high-quality kraft pulps. These are the first results reported in which standing trees dead for as long as 50 years produced high-quality bleached and unbleached pulps.

scholarly journals Properties of bleached pulp sheets of avocado wood (Persea americana Mill.) pulped by Kraft and Soda processes

2016 ◽  
Vol 12 (1) ◽  
pp. 29-36
Author(s):  
R. Vargas ◽  
J. R. Sanjuán D. ◽  
J. A. Silva G. ◽  
J. Rivera P. ◽  
F. J. Fuentes T. ◽  
...  
Keyword(s):  
Strength Properties ◽  
Kraft Pulping ◽  
Persea Americana ◽  
Raw Material ◽  
Kraft Pulps ◽  
Reaction Conditions ◽  
Elemental Chlorine ◽  
Chemical Pulping ◽  
Pulp Strength ◽  
Soda Pulp

Chips of avocado wood (Persea americana Mill.) were pulped by means of conventional Soda and Kraft pulping processes. The pulps were bleached with an elemental-chlorine-free sequence OD1-Eop-D2, pre-setting reaction conditions for the first chlorine dioxide stage (D1) . The results show that during the chemical pulping process, avocado wood is easier to cook than other hardwoods such as eucalyptus. The avocado pulp also showed a very good bleachability, reaching brightness levels of up to 92% ISO compared to 84% for eucalyptus after the ECF bleaching sequence. The avocado Kraft pulps required more chemical input in the bleaching sequence than the Soda pulps. On the other hand, the physico-mechanical properties of the pulp were not notably reduced by the bleaching process, the Kraft pulp being stronger than the soda pulp. Strength properties of avocado are similar to those of eucalyptus; therefore this raw material constitutes a worthwhile choice for cellulosic fiber supply.

scholarly journals Current state and productivity of age-old experimental plantations of prof. V.D. Ogievsky in the northeastern part of Ukraine

2021 ◽  
Vol 63 (3) ◽  
pp. 195-202
Author(s):  
M. Zhezhkun ◽  
L.V. Demianenko
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Natural Regeneration ◽  
Health Condition ◽  
Pine Plantations ◽  
Mixed Composition ◽  
Natural Origin ◽  
Stem Wood ◽  
Current State ◽  
Pine Stands

Abstract This research is aimed at determining the health condition and productivity of Scots pine (Pinus sylvestris L.) stands created during 1906–1908 on the initiative of Prof. V. D. Ogievsky. The scheme of silvicultural experiments included: determining the influence of different widths and directions of clear felling on the natural regeneration, testing of pine plantations of pure and mixed composition and the choice of methods for their creation. In terms of health condition, 103–105-year-old artificial pine stands are weakened and their health condition is slightly worse compared to the aged pines of natural origin. The productivity of age-old linden-pine plantations is higher than of pure pine plantations, and the stock of stem wood in plantations created by seed sowing and marketability is higher compared to the plantations created by planting seedlings.

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