Catheters, wood rays, wood fibers, and axial thin-walled tissues are the main cells of poplar wood. Their tissue ratio (wood tissue ratio): 22.2%-36.0% for catheters, 6.1%-11.4% for wood rays, 52.8%-67.3% for wood fibers, and 0.1%-0.7% for axial parenchyma (see table) 2-1).
I. Structural description of several important poplar woods in China
The macroscopic structure and microscopic structure of five poplar woods, such as Populus tomentosa, are described as follows:
1. Populus
1.1 The difference between macroscopic structure and heartwood is not obvious. The wood is light yellowish white with reddish color; susceptible to fungus and insects, "false heartwood" is common; wood is shiny; no special smell and taste; texture is usually straight, structure is fine; weight and hardness. The growth wheel is obvious, the width is narrow and even (natural forest) to uneven (plantation), and there are dark bands between the wheels. There are many tube holes, slightly smaller to very small, obvious under the magnifying glass, the size is slightly consistent, the end of the growth wheel is slightly less (discrete to semi-annular hole material); the wood ray is at most, thin, visible under the magnifying glass The ray markings on the path are not obvious; there are no wavy marks on the chord surface. No gum road.
1.2 Microscopic structure The cross section of the catheter is elliptical or circular, 25-40 per mm2; the short diameter column (usually 2-3, balanced to 4-5) or separate, a few are tube holes The wall is thin (3 μm); the maximum chord diameter is 350 μm or more, and most of them are 201-300 μm. The length of the catheter molecule was 129-426 μm, with an average of 285 μm; no invasive bodies were found, and no thread thickening was observed. Single perforated oval or oval, the perforated bottom wall is slightly inclined to slope. The inter-tube pattern is inter-column, round to oval; the mouth is connotation, round to oblate. The wood fiber wall is thin, the diameter is mostly 11-25μm, the length is 820-1790μm, and the average is 1180μm; the single-grain hole has a narrow edge; the groove mouth has a lenticular shape, in-line. The wood ray cells are homologous in a single row; the end wall thickening and horizontal wall streaks are obvious, and the ray and the interstitial pores are interlaced, which are more common in the marginal cells. The axial thin wall has a small amount of tissue and is rounded.
2. Poplar
2.1 The macroscopic structure of the heartwood is not obvious. The wood is yellow to yellowish brown, and the heartwood is susceptible to insects and insects. The false heartwood (wet heartwood) with irregular brown or taupe appears. The wood texture is straight, the structure is slightly soft, the new cut down wet material has a special smell, the growth wheel is obvious, most of the growth wheels have undulations, and there are dark bands between the wheels. The tube hole is small and can be distinguished by the naked eye. The wood ray is fine, smaller than the diameter of the tube hole, visible under the magnifying glass; the diameter section is visible to the naked eye.
2.2 Microscopic structure The transverse section of the catheter is elliptical and slightly angular; the diameter of the compound tube or the oblique connection is micro-serrated, a few are separate; 40-75 per mm2. The chord has a diameter of 49-77 μm and a thin wall (2.7 μm). The length of the catheter molecule is 288-1025 μm, generally 530-760 μm long. Occasionally the invading body; single perforation, the bottom wall is inclined. The sidewalls have interdigitated holes, dense, homomorphic or polygonal, and the pores are connotation. The wood fiber wall is thin, 14-23 μm in diameter and 900-1850 μm in length. The wood ray has the same type of single column, 6-9 per mm, the wood ray is generally 10-16 cells, the cell is oblong, and the cell contains brown gum-like deposits. The number of axial thin-walled structures is small, and the intermittent short lines are arranged at the wheel boundary.
3. Big leaf poplar
3.1 Macroscopic structure The heartwood and sapwood are indistinguishable, the wood is yellowish white or yellow, and the heartwood part is often affected by worms, which is grayish brown or yellowish, shiny; no special smell and taste. The growth wheel is obvious, the width is slightly uniform, and the wheel boundary is a light-colored thin line; 5-7 rounds per cm. The tube hole is slightly more, usually slightly smaller, not visible under the magnifying glass; gradually reduced from the inside to the outside (half-ring hole or loose hole material); diameter column; axial thin-walled tissue is not seen. The wood ray is at most; very fine to very fine, not obvious under the magnifying glass, smaller than the tube hole; the ray pattern of the radial section is not visible.
3.2 Microscopic structure The cross-section of the duct is oval and elliptical, with a polygonal contour; most of each 20 mm is 20-30; short-diameter columns and individual tubes, occasionally tube-holes; diameter; wall Thin (3μm); maximum chord diameter 126μm, most 80-105μm; duct molecular length 390-950μm; occasionally invading body, no thread thickening. Single perforation, oval or elliptical, rarely round; perforated bottom wall slightly inclined or inclined. The inter-tube pattern is inter-column, polygonal, and long-length 11-14μm; the grain mouth is connotation, round or oval. The wall of the wood fiber is thin, and the diameter is mostly 11-14 μm; the groove mouth has a lenticular shape or a circular shape, and is in-line. Wood ray is non-stacked, 7-12 roots per mm. The ray tissue is homogenous in a single row, with a single row of ray width of 8-20 μm; high 2-37 cells (48-790 μm), most of which are 10-20 cells (180-400 μm) high. The ray cells are oval or elliptical, no gums and crystals are seen, and the end wall thickening and horizontal wall pores are not obvious or slightly obvious. The ray and the interstitial pores are interdigitated, which are more common in the edge array cells. No intercourse. The amount of axial thin-walled tissue is small; the wheel-like shape (usually one column of cells wide), the sparse star is scattered; the thick-walled cell end wall nodular thickening is not obvious or slightly obvious; no gums and crystals are seen.
4.滇æ¨(P. yunnanensis)
4.1 Macrostructures There is no difference in heartwood. The wood is yellowish white to yellowish brown, and the wood of the heartwood is susceptible to microbial color; it is shiny; there is no special smell and taste. The growth wheel is obvious, the width is not uniform, and the bands are crossed with dark bands; 1-2 rounds per cm. The tube hole is slightly more; slightly smaller, obvious under the magnifying glass; the size is slightly uniform, the distribution is relatively uniform (half-ring hole material to loose hole material), less near the growth wheel; the diameter column; the invasive body is not seen. Axial thin-walled tissue is missing. The wood ray is at most, very fine to very fine, not obvious under the magnifying glass; the ray markings on the radial cutting surface are not visible. No wave marks and intercellular channels.
4.2 Micro-construction The cross-section of the catheter is oval or round, slightly polygonal; 235-55 per mm; usually 2-4 for short-row complex holes) and separate, rare long-diameter Tube hole (5-6), occasionally tube hole group, diameter column; wall thin (3μm); maximum chord diameter 102μm, most 60-90μm; catheter molecule length 410-950μm, average 697μm; , no thread thickening. Single perforation, oval, elliptical and round; the perforated bottom is slightly inclined to the inclination, the interstitial pores are interdigitated, oval, long diameter 11-14μm; grain mouth connotation, lenticular and elliptical. Wood fiber wall is thin; most of the diameter is 15-25μm, length 780-1760μm, average 1165μm; the number of marginal holes is large, obvious, round and oval, diameter 3-4μm; grain mouth connotation, lens shape and ellipse Shape, inline. Wood ray is non-stacked, 8-13 roots per mm. The ray tissue is in the same shape as a single column. Single-row ray is 10-20 μm wide; 2-33 cells are high, and most are 5-15 cells high. The ray cells are oval and elliptical, the gum is rare, the crystal is not seen, the end wall is thickened and the horizontal wall is many and obvious. The pattern between the ray and the catheter is a single-grained hole, which is juxtaposed, and is only found in the cells of the edge array. No intercourse. The amount of axial thin-walled tissue is small, the wheel-bound shape (usually one column of cells wide), and the sparse star is scattered; the thick-walled cell end wall wall-like thickening is not obvious or slightly obvious; the gum and crystal are not seen.
5. Jia Yang
5.1 Macrostructures The distinction between heartwood and sapwood is not obvious. Wood milky white; dull, no special smell and taste; growth wheel is obvious, uneven or slightly uniform, with thin lines between the annual rings and 2.4 rounds per cm. The tube holes are slightly smaller, obvious under the magnifying glass, alone or in duplicate tubes (2-8 or more), diameter or diagonal. The tube hole is slightly larger at the beginning of the annual ring than at the end of the annual ring (half-ring hole or loose hole material); the invasive body is rare, and the axial thin-walled structure is missing. The wood ray is generally slightly less, very fine, visible under the magnifying glass; the ray markings on the radial cutting surface are not obvious, the chord surface has no wavy marks, and there is no gum lane.
5.2 Microscopic structure The transverse section of the catheter is oval, elliptical or polygonal; the wall is thin, 245-71 per mm, with an average of 54; the maximum chord diameter is above 88 μm, most of which is 63 μm, and the length of the catheter is 389-666 μm. Most of them are around 537μm; single perforation, elliptical; no thread thickening; inter-tube perforation, large, dense, round, oval or elliptical, grained mouth connotation, lenticular. The wood fiber wall is thin, often with glial fibers, with a diameter of 15-21 μm, most of which are about 18 μm, and have a length of 605-1472 μm, with an average of 1017 μm. The wood ray is non-stacked, 6-11 per mm, with an average of about 8, the ray tissue is a single column, 1 column wide (about 12 μm), 5-30 cells high, and the horizontal ray cells are oval or oval; Containing gum, the crystal is not seen; the end wall is inclined or curved, and the knot is thickened obviously, and the number is large. The number of axial thin-walled structures is small, and it is a wheel-shaped shape, and continuous or discontinuous thin lines are formed at the edges of the late wood strip.
Second, the relationship between poplar wood structure and wood properties
1. Porosity of poplar wood
(1) The cell walls of the ducts and fibers of poplar wood are thin, resulting in low density of wood, especially the artificial forest poplar is more prominent than the natural poplar wood.
(2) The porosity of the wood makes the wood have better resilience after being stressed, and the resilience of the transverse grain is more significant, so the poplar wood has better shock absorption performance.
(3) The porosity of poplar wood makes the preservatives and liquids easy to invade, which is very beneficial to wood antisepsis, pulping and bleaching. However, due to its porosity, the insects are also easy to enter, making the poplar wood susceptible to bacteria and insects, decaying and deteriorating.
2. Variability of poplar wood
The variability of wood is manifested in many aspects such as interspecific, clonal, inter-plant, different tree age, different parts of the trunk, and different forest management measures. Therefore, the improved breeding of trees and the correct forest management measures have a significant impact on wood quality.
(1) Variation of wood between poplar species and clones
Many kinds of studies have been carried out at home and abroad. Chong.WW et al. selected 5260 poplar (P. tristis Fisch. × P. balsanifera L. cv. Tristis 1), 5273 poplar (P. deltoides Bartr), 5326 poplar (at P. tristis Fisch. × P. balsanifera L. cv. Tristis 1) in the forestry test station in Reinaland, Wisconsin, USA. P.× euramericana (Dode)Gruiner cv.eugenii), 5339 yang (P.alba L.×grandidentata Michx.), 5351 yang (P.spp.), 5337 yang (P.×euramericana (Dode)Gruiner cv. Wisconsin -5) Six clones were studied for fiber length and cell tissue ratio. The results showed that the differences in the anatomical properties between the selected clones and the trunk were very obvious. The wood anatomy, fiber morphology, and microfilaments of the secondary wall of the cell were analyzed for 13 poplar clones by the Chinese Academy of Forestry. A number of tests for the relative crystallinity, chemical composition, wood density, and pulping of horns and cellulose. The results also showed that the differences between the clones were significant. Zeng Qiyun of the Institute of Ecological Application of the Chinese Academy of Sciences also studied the variation of wood fiber lengths of different species or types of Populus tomentosa in Hebei Province and reached the same conclusion.
(2) Variability of different parts of the trunk: including the variation of the trunk up and down direction (axial direction) and the trunk inside and outside direction (radial direction). The laws of this variation are not consistent, and some even lead to the opposite conclusion. However, the total variation law, from the ground diameter to the crown direction, the fiber gradually becomes shorter or grows first and then becomes shorter. At a certain height, from the medulla to the bark, the fiber length gradually increases with the increase of the annual ring, and the trees are in the young forest. The fiber length increased rapidly, and the fiber length did not increase at the maturity stage. Some species have been growing slowly (Table 2-7).
(3) Young and mature wood of poplar wood: The difference between the growth of poplar and the annual ring of bark, there is a relative unity within a certain range. After the trees are mature, the annual rings close to the medulla and the woods near the outer rings of the trunk are significantly different. The core is the young material and the outside is the mature material. Young wood, low wood density, short fiber, high extract content, high pH, ​​dry cracking, severe deformation, high water content, low strength, poor stiffness, and mature materials. The young trees and mature materials of poplars, plantations are generally bounded by 15 years.
1.multifunction Nail Table;
2.dust collector(fan) , handrest and lamp avilable;
3.wood &tempered glass top(white/ black/ clear glass color avilable);
4.UV lamp can be included;
5.reasonable and fashion design;
If you are finding a reliable beauty and salon equipment manufacturer, please contact with us. We would provide the best quality beauty and salon products with competitive price to you.
Related Products:nail manicure table,Beauty nail spa table.
Nail Table
Nail Table,Manicure Nail Table ,Cosmetic Manicure Table,Wood Nail Tables
ChaoHui Beauty Salon Equipment Co., Ltd. , https://www.facialbed.nl