CN114147827A - Solid wood layered compression method based on moisture distribution regulation and control - Google Patents
Solid wood layered compression method based on moisture distribution regulation and control Download PDFInfo
- Publication number
- CN114147827A CN114147827A CN202111527104.4A CN202111527104A CN114147827A CN 114147827 A CN114147827 A CN 114147827A CN 202111527104 A CN202111527104 A CN 202111527104A CN 114147827 A CN114147827 A CN 114147827A
- Authority
- CN
- China
- Prior art keywords
- wood
- layer
- moisture
- distribution
- soaked
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000002023 wood Substances 0.000 title claims abstract description 192
- 238000009826 distribution Methods 0.000 title claims abstract description 88
- 238000000034 method Methods 0.000 title claims abstract description 36
- 239000007787 solid Substances 0.000 title claims abstract description 36
- 238000007906 compression Methods 0.000 title claims abstract description 35
- 230000006835 compression Effects 0.000 title claims abstract description 32
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 90
- 239000010410 layer Substances 0.000 claims abstract description 65
- 239000002344 surface layer Substances 0.000 claims abstract description 55
- 238000010438 heat treatment Methods 0.000 claims abstract description 25
- 238000002791 soaking Methods 0.000 claims abstract description 25
- 238000013508 migration Methods 0.000 claims abstract description 15
- 230000005012 migration Effects 0.000 claims abstract description 15
- 238000007789 sealing Methods 0.000 claims abstract description 8
- 238000009828 non-uniform distribution Methods 0.000 claims abstract description 6
- 238000001035 drying Methods 0.000 claims description 21
- 238000010586 diagram Methods 0.000 claims description 9
- 238000000926 separation method Methods 0.000 claims description 5
- 238000012800 visualization Methods 0.000 claims description 5
- 230000035515 penetration Effects 0.000 claims description 4
- 238000013519 translation Methods 0.000 claims description 4
- 230000008595 infiltration Effects 0.000 claims description 3
- 238000001764 infiltration Methods 0.000 claims description 3
- 239000002352 surface water Substances 0.000 claims description 3
- 238000001704 evaporation Methods 0.000 claims description 2
- 230000008020 evaporation Effects 0.000 claims description 2
- 230000015572 biosynthetic process Effects 0.000 claims 1
- 238000004364 calculation method Methods 0.000 claims 1
- 238000001739 density measurement Methods 0.000 claims 1
- 238000009740 moulding (composite fabrication) Methods 0.000 claims 1
- 239000007921 spray Substances 0.000 claims 1
- 238000012360 testing method Methods 0.000 claims 1
- 238000005507 spraying Methods 0.000 abstract description 4
- 230000001276 controlling effect Effects 0.000 description 5
- 238000012545 processing Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 230000000007 visual effect Effects 0.000 description 4
- 238000010521 absorption reaction Methods 0.000 description 3
- 230000033001 locomotion Effects 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 241000219000 Populus Species 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 229920002488 Hemicellulose Polymers 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 230000004323 axial length Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229920005610 lignin Polymers 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27M—WORKING OF WOOD NOT PROVIDED FOR IN SUBCLASSES B27B - B27L; MANUFACTURE OF SPECIFIC WOODEN ARTICLES
- B27M1/00—Working of wood not provided for in subclasses B27B - B27L, e.g. by stretching
- B27M1/08—Working of wood not provided for in subclasses B27B - B27L, e.g. by stretching by multi-step processes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27D—WORKING VENEER OR PLYWOOD
- B27D3/00—Veneer presses; Press plates; Plywood presses
- B27D3/02—Veneer presses; Press plates; Plywood presses with a plurality of press plates, i.e. multi- platen hot presses
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27K1/00—Damping wood
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
- B27K3/02—Processes; Apparatus
- B27K3/0228—Spraying apparatus, e.g. tunnels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
- B27K3/02—Processes; Apparatus
- B27K3/08—Impregnating by pressure, e.g. vacuum impregnation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27K5/00—Treating of wood not provided for in groups B27K1/00, B27K3/00
- B27K5/04—Combined bleaching or impregnating and drying of wood
Abstract
The invention discloses a solid wood layered compression method based on moisture distribution regulation and control, which comprises the following steps: a. soaking, soaking or spraying the wood with the moisture content of 6-28% for 1-20 hours to form a high-moisture-content layer near the surface of the wood, so as to obtain surface-layer soaked wood with the initial moisture content in non-uniform distribution; b. and (3) carrying out sealing placement and/or heating treatment on the surface-layer soaked wood, so that the high-water-content layer on the surface of the wood migrates from the surface layer to the center, further controlling the water content distribution in the thickness direction of the wood, and compressing by mechanical force to obtain the laminated compressed wood. The method can regulate and control the water migration and the water content distribution in the wood, enables the water content distribution to be visualized, and has the advantages of simple operation and convenient regulation and control.
Description
Technical Field
The invention relates to a solid wood layered compression method based on moisture distribution regulation and control, and belongs to the field of wood processing.
Background
In the wood components, the amorphous regions of cellulose, hemicellulose and lignin molecules have strong affinity to polar molecules, so that the wood is easy to absorb moisture and expand, and the wood is one of important intrinsic factors for converting the elasticity into the plasticity of the wood. After moisture absorption or water absorption, the bonding force among the wood components is weakened, and the wood components can be converted from a high elastic state into a plastic state; in a high-temperature environment, due to the acceleration of molecular thermal motion, the glass transition temperature of the wood is reduced, and the wood can be converted from an elastic state to a plastic state. Therefore, the temperature and the water content are important factors influencing the softening performance of the wood and the conversion between elasticity and plasticity, and are also important process parameters for realizing the layered compression of the wood, fixing the compression deformation and obtaining the compressed wood with high stability.
At present, the research on the change of the internal water content of the wood is an application basic research which is developed by taking the drying of the wood as a target under the condition that the initial water content is uniform or under the condition that the internal part is high and the external part is low and the natural distribution state is low. In the heating and drying process of the high-moisture-content wood, the average moisture content is gradually reduced along with the extension of the drying time, the low-moisture-content dry area of the surface layer is gradually increased, and the high-moisture-content wet area of the middle layer is gradually reduced, so that the wood is gradually dried from the surface layer to the center, and the dried wood is obtained.
One of the main problems to be solved by the solid wood lamellar compression is to regulate and control the distribution of the water content in the wood. In the compression process of the solid wood layers, in order to control the position of the compression layer, the distribution of the moisture content in the wood must be in a non-uniform state all the time, so the distribution of the initial moisture content before compression is completely different from the drying of the wood. On the basis, the development of the control method for the internal water migration and the water content distribution of the wood can provide a new way for regulating and controlling the compression position and the compression layer thickness in the laminated compression process of the solid wood and the production of the laminated compressed wood, and has important significance for the high-quality utilization and the added value improvement of the fast growing wood of the artificial forest.
Disclosure of Invention
The invention aims to provide a solid wood layered compression method based on moisture distribution regulation. The invention can regulate and control the water content distribution in the thickness direction in the wood, is convenient for the compression of the solid wood layers, and has the advantages of convenient and accurate regulation and control.
The technical scheme of the invention is as follows: according to the solid wood layered compression method based on water distribution regulation and control, a non-uniform distribution state of high surface water content and low internal water content is formed in the wood through drying and then soaking treatment; then, forming water migration in the thickness direction in the wood through the adjustment and control of the standing time or the heating treatment under the clamping of a hot plate, and controlling the distribution of the water content in the thickness direction in the wood; and determining the position of the compression layer by water content distribution, and applying external force for compression to realize accurate distribution regulation and control of the compression position of the solid wood layer.
According to the method for calculating the moisture distribution, the moisture content in the thickness direction of the wood is calculated by taking each section density measuring step length as a thickness unit according to the section density difference value of the surface-layer soaked wood and the dried wood, the moisture content distribution map in the thickness direction of the wood is drawn, and the functional relation between the maximum moisture content of the high-moisture-content layer and the heating time is obtained according to the moisture content distribution map in the thickness direction of the wood:
y＝aebx，
wherein a and b are constants, y is the position of the maximum water content in the high water content layer, and x is the heating time.
In the method for compressing the solid wood layer based on the moisture distribution control, the poplar with the thickness of 20mm is soaked in water for 2 hours, then is placed at the normal temperature for 18 hours, and finally is clamped and heated by a hot plate at the temperature of 180 ℃, wherein a is 2.441, and b is 0.0025.
In the foregoing method for compressing solid wood layers based on moisture distribution control, the relation for determining the position of the compressed layer through moisture distribution is as follows:
y＝1.343x-0.078；
wherein y is the relative position of the density peak value, and x is the relative position of the maximum water content in the high water content layer.
In the method for compressing the solid wood layer based on the water distribution regulation and control, the soaking treatment is to treat the wood with the water content of 6-28% for 1-20 hours by soaking, soaking or spraying.
According to the solid wood layer compression method based on water distribution regulation and control, the water temperature is increased, and the penetration depth of the surface water of the wood and the total water amount of the high-water-content layer in unit time are increased.
According to the method for compressing the solid wood layers based on moisture distribution regulation and control, the wood is subjected to heating treatment under the clamping of a hot plate at the temperature of 40-240 ℃, the pressure is 1.5-10MPa, and the compression speed is 0.1-2 mm/s.
In the method for compressing the solid wood layer based on moisture distribution regulation, the wood is placed under the condition that moisture evaporation does not occur.
In the solid wood layered compression method based on moisture distribution regulation and control, the wood is placed in a sealed bag for sealed placement treatment, and the placing environment temperature is 1-150 ℃.
According to the method for compressing the solid wood layers based on the moisture distribution regulation and control, samples are taken from the middle of the surface-layer soaked wood, or the middle of the surface-layer soaked wood after being placed or heated under the clamping of a hot plate, the section density in the thickness direction of the wood is tested, the surface-layer soaked wood is obtained, or the density distribution curve in the thickness direction of the wood after the surface-layer soaked wood is placed or the surface-layer soaked wood is heated under the clamping of the hot plate is obtained, then the surface-layer soaked wood is dried in a drying box at 103 ℃ to be completely dry, the section density is measured 2 times after the surface-layer soaked wood is taken out, and the density distribution curve in the thickness direction of the surface-layer soaked wood after being dried is obtained according to the soaking depth and the dry shrinkage coefficient of the wood;
horizontally overlapping the density distribution curve of the dried wood to the non-infiltration area of the soaked wood with the density distribution curve of the soaked wood on the surface layer to obtain a drying horizontal moving curve; and obtaining the moisture migration range and depth through the difference between the drying translation curve and the density distribution curve of the surface layer soaking wood and the separation point formed by the two curves due to the density difference, so as to realize the visualization of the surface layer soaking state and the moisture distribution.
According to the solid wood layer compression method based on moisture distribution regulation, the section density is measured by a section density analyzer, and the scanning step length is 15-1000 microns.
Compared with the prior art, the invention has the following beneficial effects:
1. according to the invention, through drying and soaking treatment, a non-uniform distribution state of high surface moisture content and low internal moisture content is formed in the wood; then, through the adjustment and control of the standing time and the heating treatment under the clamping of a hot plate, the moisture migration is formed in the thickness direction of the interior of the wood, and the moisture content distribution in the thickness direction of the interior of the wood is controlled; and then the position of the compression layer is determined through the distribution of the water content, so that the precise distribution regulation and control of the compression position of the solid wood layer is realized, the prepared wood can meet the relevant requirements of the compression of the solid wood layer, and the method has the advantages of simplicity, convenience and accuracy in regulation and control. The invention can provide a new way and a new idea for regulating and controlling the compression position and the compression layer thickness in the laminated compression process of the solid wood and producing the laminated compressed wood.
2. When the section density method is adopted to measure the water distribution in the wood, the section density distribution curves of the surface-layer soaked wood and the dried wood and the translation curve after drying are placed on the same coordinate system, so that the visualization of the surface-layer soaking state and the water content distribution can be realized, and the subsequent visualization regulation and control of the water migration and the water content distribution in the wood can be conveniently carried out.
Drawings
FIG. 1 is a two-dimensional functional relationship of the maximum water cut position of the high water cut region of the present invention as the heating time increases;
FIG. 2 is a schematic diagram showing a three-dimensional relationship in which the maximum water content position of a high water content region in the thickness direction of a sheet material changes as the heating time increases;
FIG. 3 is a graphical illustration of the relative position of the density peaks as a function of the relative position of the moisture content peaks;
FIG. 4 is a density distribution diagram in the thickness direction of the wood after the wood is soaked in water and dried;
FIG. 5 is a time series graph of water absorption capacity of the surface of wood at normal temperature (20 ℃);
FIG. 6 is a schematic diagram of water cut distribution regulation and sampling for stratified water cut determination;
FIG. 7 is a diagram of a distribution of moisture content in the thickness direction of the wood according to the measured value of the layered moisture content and the calculated value of the functional relationship;
FIG. 8 is a visual representation of water migration through the thickness of the submerged wood at different flooding times;
FIG. 9 is a visual diagram showing the movement of the surface layer high water content area of the surface-soaked wood from the surface layer to the center after the sealing placement and the heat treatment;
fig. 10 is a graph showing changes in moisture content of the high moisture content region in the wood with increasing heating time.
Detailed Description
The invention is further illustrated by the following figures and examples, which are not to be construed as limiting the invention.
Example (b): the method for compressing the solid wood layer based on the moisture distribution regulation comprises the following materials and instruments:
preparing wood:
(1) and wood: including fast growing wood of artificial forest and natural forest wood, all coniferous wood and broad-leaved wood.
(2) Processing the wood into a plate, wherein the plate can be a chord plate, a chord radial plate and a radial plate, and preferably the chord plate; the thickness is 0.5-500mm, and can be any workable thickness, preferably 1-150 mm;
(3) planing and sanding the sawn board surface of the wood to enable the surface to be flat, or not carrying out surface flattening treatment on the sawn board;
instrumentation and equipment
(1) The wood humidifying equipment can adopt spraying, soaking in a water tank and pressurizing soaking modes so as to take the soaking moisture in a certain depth range below the surface of the wood as the standard. The water temperature is 0-100 ℃, and the normal temperature is preferred.
(2) Two heatable metal plates, the thickness of the metal plate is more than 2mm, and the heating metal plate is provided with a temperature control device or a hot press; the temperature regulation range is 0-250 ℃;
(3) and the section densitometer is used for measuring the density distribution in the thickness direction of the plate, and the scanning step length of the densitometer is 15-1000 mu m.
After preparing the required materials, forming a non-uniform distribution state of high surface moisture content and low internal moisture content in the wood through drying and soaking treatment; then, through the adjustment and control of the standing time and the heating treatment under the clamping of a hot plate, the moisture migration is formed in the thickness direction of the interior of the wood, and the moisture content distribution in the thickness direction of the interior of the wood is controlled; and then the position of the compressed layer is determined through the distribution of the water content, so that the precise distribution and regulation of the compressed position of the solid wood layer are realized. Specifically, the method comprises the following steps:
performing end-capping treatment or non-treatment on the cross section of the wood with the moisture content of 6-28% (preferably, the moisture content is 9-23%) by using a hydrophobic material, and performing soaking, water soaking or spraying treatment for 1-20 hours to form a high-moisture-content layer near the surface of the wood, so as to obtain the surface-layer soaked wood with the initial moisture content in non-uniform distribution (namely, the surface-layer moisture content is high, and the internal moisture content is low); wherein the depth of penetration of water and the total water amount of the high water content layer in unit time can be increased by prolonging the soaking time or increasing the water temperature, as shown in fig. 1 and 2, the water content distribution is calculated by taking each step as a thickness unit according to the section density difference of the surface soaked wood and the dried wood, the water content distribution graph in the thickness direction of the wood is drawn, and the function relation between the maximum water content of the high water content layer (region) and the heating time is y ═ aebx，
In the present example, poplar with a thickness of 20mm was soaked in water for 2 hours, left to stand for 18 hours, and then heated at 180 ℃, a was 2.441, b was 0.0025, y was the position of the maximum moisture content in the high moisture content layer, and x was the heating time.
The position of the compressed layer is determined by the water content distribution, and as shown in fig. 3, the relation is as follows:
y＝1.343x-0.078；
wherein y is the relative position of the density peak value, and x is the relative position of the maximum water content in the high water content layer.
In this embodiment, the profile density is measured by a profile density analyzer, and the scanning is performed from the upper surface to the lower surface during the measurement, and the scanning step length is 15 to 1000 μm.
Specifically, a sample (50mm (L) × 50mm (T) × 20mm (R)) is taken from the middle part of the surface layer soaked wood, the section density in the thickness direction of the wood is tested, the density distribution curve in the thickness direction of the surface layer soaked wood is obtained, then the surface layer soaked wood is dried in a drying oven at 103 ℃ to be completely dry, the section density is measured 2 times after the surface layer soaked wood is taken out, and the density distribution curve in the thickness direction of the surface layer soaked wood after the surface layer soaked wood is dried is obtained according to the soaking depth and the drying shrinkage coefficient of the wood;
horizontally overlapping the density distribution curve of the dried wood to the soaked wood moisture non-infiltration area of the density distribution curve of the surface soaked wood to obtain a drying horizontal moving curve; the moisture migration range and depth were obtained from the separation point by the difference between the dry translation curve and the density distribution curve of the surface-layer-soaked wood and the separation point formed by the two curves due to the density difference, as shown in fig. 4, where the separation points are a and b in fig. 4. This density difference is derived from the difference in the water content by water immersion for the same piece of wood, and therefore the water penetration range (the diagonal line portion) and the depth (the distance from the point a to the upper surface and the distance from the point b to the lower surface) can be visually recognized from the separated state of the two curves. Therefore, the invention places the surface layer soaked wood, the dried wood and the section density distribution curve translated after drying in the same coordinate system, and can realize the visualization of the surface layer soaked state and the water distribution.
Meanwhile, since the moisture diffusion coefficient in the longitudinal and transverse directions in the wood is only about 5.0 × 10-6cm2S and 0.3X 10-6cm2In terms of transverse water diffusion, even when the wood is immersed in water, the water remains on the surface layer within tens of hours, and a high water content layer (region) is formed in the thickness direction of the board. As shown in fig. 5. Therefore, the present invention can form a high water content layer near the surface of the wood through the above steps.
Further, in this example, the moisture content of the wood was measured by a method of actually measuring the moisture content by slicing the wood in layers, and the migration of moisture was analyzed from the change in the moisture content. FIG. 6 is a schematic view of a sampling method for measuring a water content of a layer. The dimension is 400(L) multiplied by 150(T), the thickness (R) of the plate, the plate which is soaked, placed, preheated and the like under the condition of room temperature, firstly, a batten with the axial length of 20mm is sawed out from the position 20mm away from the end of the plate, then, two ends of the batten are respectively removed by 25mm, and the rest part is a wood block with the chord-wise length of 50 mm. The block was divided into n layers (n is 5 to 30 layers) of equal thickness from the upper surface to the lower surface in the thickness direction, and the samples of the layered water content were sawed out. Immediately after sampling, the mass of each layer of the sample was weighed, all the samples were dried to the absolute dryness, the sample mass was weighed again, the layered moisture content of the wood was calculated according to the formula (1), and a moisture content distribution diagram in the thickness direction of the wood was drawn, as shown in fig. 7.
In the formula: MC (monomer casting)iRepresents the water content of the ith layer (i ═ 1, 2.., n), in units%;
mirepresents the actual mass of the ith layer (i ═ 1, 2.., n), in g;
m0represents the oven dry mass (i ═ 1, 2.., n), in g, of the ith layer.
In this embodiment, put into the sealed bag with top layer soaked timber and place, come near the timber surface to form a high moisture content layer through placing and migrate to timber center to compare the water migration visual map of soaked timber thickness direction under the different soaking time, as shown in fig. 8.
Placing the surface layer soaked wood, and heating (or preheating) the surface layer soaked wood under 40-240 deg.C hot plate clamping at 1.5-10MPa and compression speed of 0.1-2 mm/s. The hot plate comprises a metal plate which can be heated in any form or is directly heated on a hot press, the preheating temperature is preferably 90-180 ℃, and then a visual graph of the movement of a surface layer high water content area of the surface layer soaked wood from the surface layer to the center after sealing placement and heating treatment is obtained by adjusting and controlling the heating time (the time is 1-1000s), as shown in fig. 9 and 10, as can be seen from fig. 9 and 10, by controlling the heating time, the invention can control the migration of the surface layer high water content layer of the wood surface layer from the surface layer to the center, and further control the water content distribution in the thickness direction of the board. Therefore, according to the method, the water content of the surface-layer soaked wood with different sealing placing and/or heating processing time is visualized according to the different sealing placing and heating processing time, the migration position of the high-water-content layer on the surface of the wood from the surface layer to the center is linearly controlled according to the water content distribution diagrams of the surface-layer soaked wood at different time points of the sealing placing or heating processing, and the water content distribution in the thickness direction of the wood is further regulated and controlled.
Claims (10)
1. The solid wood layered compression method based on the water distribution regulation is characterized in that: after drying, soaking, and forming a non-uniform distribution state of high surface moisture content and low internal moisture content in the wood; then, forming water migration in the thickness direction in the wood through the adjustment and control of the standing time or the heating treatment under the clamping of a hot plate, and controlling the distribution of the water content in the thickness direction in the wood; and determining the position of the compression layer by water content distribution, and applying external force for compression to realize accurate distribution regulation and control of the compression position of the solid wood layer.
2. The method for compressing solid wood in layers based on moisture distribution control as claimed in claim 1, wherein: the calculation method of the moisture content distribution comprises the following steps of calculating the moisture content in the thickness direction of the wood by taking each section density measurement step length as a thickness unit according to the section density difference value of the surface-layer soaked wood and the dried wood, drawing a moisture content distribution diagram in the thickness direction of the wood, and obtaining the functional relation between the maximum moisture content of the high-moisture-content layer and the heating time according to the moisture content distribution diagram in the thickness direction of the wood:
y＝aebx，
wherein a and b are constants, y is the position of the maximum water content in the high water content layer, and x is the heating time.
3. The method for compressing solid wood in layers based on moisture distribution control as claimed in claim 2, wherein: the relational expression for determining the position of the compressed layer formation from the water content distribution is as follows:
y＝1.343x-0.078；
wherein y is the relative position of the density peak value, and x is the relative position of the maximum water content in the high water content layer.
4. The method for compressing solid wood in layers based on moisture distribution control as claimed in claim 2, wherein: the soaking treatment is to soak, soak or spray the wood with the water content of 6-28% for 1-20 hours.
5. The method for compressing solid wood in layers based on moisture distribution control as claimed in claim 4, wherein: by raising the water temperature, the penetration depth of the surface water of the wood in unit time and the total water amount of the high water content layer are increased.
6. The method for compressing solid wood in layers based on moisture distribution control as claimed in claim 1, wherein: the wood is heated under the clamping of a hot plate at the temperature of 40-240 ℃, the pressure is 1.5-10MPa, and the compression speed is 0.1-2 mm/s.
7. The method for compressing solid wood in layers based on moisture distribution control as claimed in claim 1, wherein: the wood is placed under the condition that the moisture evaporation does not occur.
8. The method for compressing solid wood in layers based on moisture distribution control as claimed in claim 7, wherein: the placing is to place the wood in a sealing bag for sealing and placing treatment, and the placing environment temperature is 1-150 ℃.
9. The method for compressing solid wood in layers based on moisture distribution control as claimed in claim 1, wherein: taking a sample from the middle part of the surface-layer soaked wood, or the middle part of the wood after the surface-layer soaked wood is placed, or the surface-layer soaked wood is heated under the clamping of a hot plate, testing the section density in the thickness direction of the wood to obtain the surface-layer soaked wood, or the middle part of the wood after the surface-layer soaked wood is placed, or the middle part of the wood after the surface-layer soaked wood is heated under the clamping of the hot plate, then drying the surface-layer soaked wood in a drying box at 103 ℃ to be completely dry, measuring the section density 2 times after taking out, and then obtaining the density distribution curve in the thickness direction of the surface-layer soaked wood after drying according to the soaking depth and the dry shrinkage coefficient of the wood;
horizontally overlapping the density distribution curve of the dried wood to the non-infiltration area of the soaked wood with the density distribution curve of the soaked wood on the surface layer to obtain a drying horizontal moving curve; and obtaining the moisture migration range and depth through the difference between the drying translation curve and the density distribution curve of the surface layer soaking wood and the separation point formed by the two curves due to the density difference, so as to realize the visualization of the surface layer soaking state and the moisture distribution.
10. The method for compressing solid wood in layers based on moisture distribution control as claimed in claim 9, wherein: the section density is measured by a section density analyzer, and the scanning step length is 15-1000 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111527104.4A CN114147827A (en) | 2021-12-14 | 2021-12-14 | Solid wood layered compression method based on moisture distribution regulation and control |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111527104.4A CN114147827A (en) | 2021-12-14 | 2021-12-14 | Solid wood layered compression method based on moisture distribution regulation and control |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114147827A true CN114147827A (en) | 2022-03-08 |
Family
ID=80451024
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111527104.4A Pending CN114147827A (en) | 2021-12-14 | 2021-12-14 | Solid wood layered compression method based on moisture distribution regulation and control |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114147827A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115139380A (en) * | 2022-06-30 | 2022-10-04 | 华南农业大学 | Wood strengthening treatment method and carbon material thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1202848A1 (en) * | 1999-05-17 | 2002-05-08 | Primwood AB | Method and device for compressing wood |
| US20110262727A1 (en) * | 2009-12-26 | 2011-10-27 | Zhejiang Shiyou Timber Co. Ltd. | Type of wood section material and its manufacturing method |
| CN107263657A (en) * | 2017-06-07 | 2017-10-20 | 中国林业科学研究院木材工业研究所 | The thickness of compressed layer control method of timber stratiform compression |
| CN108638277A (en) * | 2018-06-11 | 2018-10-12 | 南京林业大学 | A kind of novel wooden structures material and preparation method thereof with stability and durability |
| CN108698381A (en) * | 2016-02-23 | 2018-10-23 | 木材金融公司 | Method for producing multilayer laminate and sheets thus obtained |
| CN108943208A (en) * | 2018-08-07 | 2018-12-07 | 中国林业科学研究院木材工业研究所 | A kind of solid wood compression compact sheet production method that Density Distribution is controllable |
-
2021
- 2021-12-14 CN CN202111527104.4A patent/CN114147827A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1202848A1 (en) * | 1999-05-17 | 2002-05-08 | Primwood AB | Method and device for compressing wood |
| US20110262727A1 (en) * | 2009-12-26 | 2011-10-27 | Zhejiang Shiyou Timber Co. Ltd. | Type of wood section material and its manufacturing method |
| CN108698381A (en) * | 2016-02-23 | 2018-10-23 | 木材金融公司 | Method for producing multilayer laminate and sheets thus obtained |
| CN107263657A (en) * | 2017-06-07 | 2017-10-20 | 中国林业科学研究院木材工业研究所 | The thickness of compressed layer control method of timber stratiform compression |
| CN108638277A (en) * | 2018-06-11 | 2018-10-12 | 南京林业大学 | A kind of novel wooden structures material and preparation method thereof with stability and durability |
| CN108943208A (en) * | 2018-08-07 | 2018-12-07 | 中国林业科学研究院木材工业研究所 | A kind of solid wood compression compact sheet production method that Density Distribution is controllable |
Non-Patent Citations (3)
| Title |
|---|
| 夏捷: "毛白杨木材层状压缩位置和厚度可控性及其变形固定", 《中国优秀硕士学位论文全文数据库农业科技辑》 * |
| 夏捷等: "水热预处理对毛白杨木材压缩层形成的影响", 《木材工业》 * |
| 高志强: "木材层状压缩可控性机理及其变形固定研究", 《中国博士学位论文全文数据库工程科技Ⅰ辑》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115139380A (en) * | 2022-06-30 | 2022-10-04 | 华南农业大学 | Wood strengthening treatment method and carbon material thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Rautkari et al. | Hardness and density profile of surface densified and thermally modified Scots pine in relation to degree of densification | |
| Bouajila et al. | Lignin plasticization to improve binderless fiberboard mechanical properties | |
| Loh et al. | Modelling anomalous moisture uptake, swelling and thermal characteristics of a rubber toughened epoxy adhesive | |
| Stamm | The fiber-saturation point of wood as obtained from electrical conductivity measurements | |
| CN114147827A (en) | Solid wood layered compression method based on moisture distribution regulation and control | |
| CN111220885B (en) | Method for estimating activation energy of transformer oil paper insulation based on frequency domain dielectric modulus | |
| CN112345435A (en) | Composite insulator silicon rubber humid heat aging performance test and evaluation method | |
| Drotning et al. | Effects of moisture on the thermal expansion of poly (methylmethacrylate) | |
| JP6876339B2 (en) | Crushed wood consolidation materials and methods based on high-frequency non-adhesive consolidation technology | |
| Antikainen et al. | Simultaneous drying and densification of silver birch (Betula pendula L.) veneers: analysis of morphology, thickness swelling, and density profile | |
| Uhmeier et al. | Influence of strain rate and temperature on the radial compression behavior of wet spruce | |
| CN110399665B (en) | Method for predicting hysteretic behavior of soil-water characteristic curve | |
| CN108844822A (en) | A method of for detecting chopped strand alkaline resistance properties | |
| CN112394101B (en) | Online detection method and device for dry shrinkage strain of wood surface | |
| CN112847708A (en) | Method for directly compacting logs into plates | |
| Wang et al. | Comparative studies on microstructures and chemical compositions of cell walls of two solid wood floorings | |
| Wu et al. | Effects of density and resin content on the rebonding performance of bamboo scrimber composite | |
| CN114720045B (en) | Online internal steam pressure testing method and device in recombined bamboo hot pressing process | |
| Tokoro et al. | Diagnosis of degradation condition of silicone rubber using hydrophobic surface analysis | |
| CN205027641U (en) | Survey test device of ceramic dry base porosity | |
| Miao et al. | Effects of furfurylation on acoustic vibration performance of paulownia wood | |
| Mulheron et al. | Moisture-induced thermal strains in glass fibre reinforced plastic compsites | |
| CN111421633B (en) | Novel hardwood based on high frequency glue-free densification | |
| RU2791976C1 (en) | Method for determining cement activity | |
| CN106696018B (en) | Cottonwood plank stuff impregnates method of modifying |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220308 |