CN115139380B - Wood strengthening treatment method and carbon material thereof - Google Patents
Wood strengthening treatment method and carbon material thereof Download PDFInfo
- Publication number
- CN115139380B CN115139380B CN202210767327.6A CN202210767327A CN115139380B CN 115139380 B CN115139380 B CN 115139380B CN 202210767327 A CN202210767327 A CN 202210767327A CN 115139380 B CN115139380 B CN 115139380B
- Authority
- CN
- China
- Prior art keywords
- wood
- treatment
- compression
- thickness
- temperature
- 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.)
- Active
Links
Classifications
-
- 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
- B27K5/001—Heating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27D—WORKING VENEER OR PLYWOOD
- B27D1/00—Joining wood veneer with any material; Forming articles thereby; Preparatory processing of surfaces to be joined, e.g. scoring
-
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E50/00—Technologies for the production of fuel of non-fossil origin
- Y02E50/10—Biofuels, e.g. bio-diesel
Abstract
The embodiment of the application discloses a wood strengthening treatment method and a carbon material thereof, wherein the treatment material is compressed under the conditions of a set treatment temperature and a set treatment pressure, the treatment material is in an absolute dry state, and the treatment temperature is greater than or equal to a wood softening temperature. According to the wood strengthening treatment method, the wood in the absolute dry state is permanently fixed after compression, moisture migration is not needed to be considered, pressure maintaining is not needed to release internal pressure generated by the moisture, the treated wood reaching the set compression rate can be further contracted after pressure relief cooling, so that the treatment period can be greatly shortened, the treatment energy consumption and the production cost are reduced, the design and execution of a compression process are simple, and the conditions of rebound, bulge and burst at the moment of pressure relief caused by the fact that the pressure maintaining time is not adapted are avoided.
Description
Technical Field
The invention relates to the technical field of wood material strengthening treatment, in particular to a wood strengthening treatment method, and also relates to a carbon material prepared by the treatment method.
Background
At present, compression densification is a main strengthening treatment means of the low-density wood material, and can improve the density, mechanical strength and other properties of the low-density wood material. The compression densification treatment principle is that under the conditions of a certain water content and high temperature, the intermolecular binding force is weakened, and the molecular thermal motion is accelerated, so that the wood is converted from an elastic state to a plastic state, and is compressed under the pressure condition to generate plastic deformation. Further, the plastic deformation is fixed by physical or chemical means.
For example, in the Chinese patent database, the publication number is CN101214675B, the invention patent named as "wood hot-pressing carbonization strengthening method" discloses a wood compression densification treatment method and a deformation fixing method thereof, comprising the steps of carrying out compression densification treatment on wood under the conditions of water content of 3-17% and temperature of 200-260 ℃ for 5-50%, and then carrying out hot-pressing carbonization treatment for 120-240 min to obtain the wood profile which is subjected to compression densification treatment and fixed deformation. In another example, the patent of the invention with publication number CN103481348B, named as an integrally reinforced solid wood section and a manufacturing method thereof, discloses that wood is preheated for 180-600 s under the pressure condition that the water content is 1-3% and the temperature is 160-210 ℃, compressed and densified for 20-30%, and after pressure maintaining for 180-600 s, the wood is subjected to heat treatment in normal pressure overheat medium with the dry bulb temperature of 180-200 ℃ for 2-4 hours to fix plastic deformation. Although the means for fixing plastic deformation are different, the two technical means adopt the treatment process of firstly carrying out compression densification treatment and then fixing plastic deformation.
Meanwhile, in the prior art, there is a technical means that a wood profile with a specific thickness layer subjected to compression densification treatment can be obtained by controlling the migration of moisture in wood.
For example, the invention patent with publication number CN102554992B, named as a surface enhanced wood section and a manufacturing method thereof, discloses that the surface compression densification section with compression ratio of 5-20% is obtained by hot pressing the wood under the pressure condition with water content of 4-15% and temperature of 230-320 ℃ for 30-600 s. In this solution, the way of fixing plastic deformation is achieved by slow decompression and cooling under cold or negative pressure conditions, since only the wood surface is compacted by compression. In another example, the publication No. CN108943208B, entitled "method for producing solid wood compression densification plate with controllable density distribution", discloses that a dry zone and a wet zone are formed in the thickness direction of wood, the difference of yield stress between the dry zone and the wet zone is controlled to be more than 0.2MPa, the wet zone is subjected to plastic deformation through hot pressing at 100-150 ℃, the pressure is maintained for 5min, the pressure is released and then the pressure is maintained for 30min, and finally the plastic deformation is fixed through heat treatment for more than 1h in normal pressure or hot medium with pressure at 180 ℃. As another example, the patent application of the invention with the publication number 114147827A and the name of solid wood lamellar compression method based on moisture distribution regulation and control discloses that after the wood with the moisture content of 6-28% is soaked for 1-20 hours, a moisture content distribution state with high surface layer moisture content and low internal moisture content is formed, the moisture migration in the wood is driven at 40-240 ℃, and compression densification treatment is carried out under the conditions of the same temperature and the compression speed of 0.1-2 mm/s, so that lamellar compression wooden profile with specific thickness layer compression densification is obtained. According to the three technical schemes, compression densification treatment of the wood section bar specific thickness layer is achieved by controlling the moisture migration position in the wood.
Disclosure of Invention
However, through creative researches and discoveries of the inventor, the means for performing the integral compression densification treatment on the wooden material has the following defects:
1. in the compression densification process, a pressure maintaining treatment with relatively long duration is needed to temporarily fix deformation formed by compression; however, the dwell time is greatly affected by factors such as tree species, initial moisture content, hot press temperature, etc., so it is not easy to determine an accurate, proper dwell time.
2. The prior art recognizes that the compression deformation must occur under wet and hot conditions, so that the factors to be controlled in the compression process include the temperature, moisture content and applied external force in the wood, and only when the applied external force is greater than the yield stress of the specific layer, the yield stress of the specific layer is affected by the interaction of the temperature and moisture content in the wood, and thus the control process is complicated.
3. When the dwell time is insufficient, the compression deformation of the wood material can rebound, compress the wood bulge and even burst at the moment of pressure relief.
4. The two factors of the water content and the hot pressing temperature in the compression densification treatment have an interactive relationship, and under the condition that one or both factors are too high, the wood material is easy to generate defects such as internal cracking, cracking and the like in the compression densification treatment process.
5. The plastic deformation formed by compression densification treatment is fixed by physical or chemical means, and the fixed plastic deformation treatment process has the advantages of high energy consumption, long period and relatively high cost; more importantly, the fixing effect is at the cost of material performance loss such as mass loss, mechanical property loss and the like, regardless of the fixing means (hot pressing, heat treatment, saturated steam treatment, superheated steam pressurizing treatment and the like). See "progress of wet and hot fixing technique and mechanism of Plastic deformation of Wood" (author Huang Rongfeng, forestry science, vol 58, 2 nd edition, 2022, 2 nd month).
The means for performing the specific thickness layer compaction treatment on the wooden material has the following defects:
even if the treatment material is compressed in a specific thickness layer (for example, in a thickness range of 5mm below the surface), the specific thickness layer needs to be compressed after the entire softening of the specific thickness layer is completed. The reason for this is that the moisture present in the wood forms a thermal resistance, the temperature of the wood itself is difficult to rise, and the moisture migrates during heating, and the softening layer and the full softening can only be controlled by softening the entire thickness layer to be compressed and then compressing it.
The prior art therefore uses a distinction between the moisture content of a layer of a particular thickness and the moisture content of layers of other thicknesses (higher than the other thickness layers) such that the yield stress of the moisture content of a layer of a particular thickness is less than the yield stress of the other thickness layers and the applied external force at the processing temperature. However, the formation of a layer of a specific thickness (wet zone) and the control of its migration position are very complex processes. Firstly, calculating the maximum water content distribution position and heating time in the thickness direction of the wood according to the required density peak distribution position in the thickness direction of the wood through two groups of formulas, and then calculating the wood soaking scheme through one group of formulas. The estimation process is complex and difficult to control, and the estimation process is greatly influenced by factors such as wood species, wood grain direction, initial water content and the like, so that the error is relatively large.
The inventors have found that the causes of the product or process defects in the above-described means for subjecting a wood material to a bulk compression densification process and the above-described means for subjecting a wood material to a specific thickness layer compression densification process are derived from an understanding of the prior art preconditions for the compression densification process. The prior art considers that the moisture absorption expansion and thermoplasticity of the wood cell wall components and the porous structure of the wood form the precondition of plastic deformation of the wood, and the wood can be compressed by applying external force which exceeds the yield stress of the wood (influenced by the moisture content and softening temperature of the wood) from the direction perpendicular to the fiber under the conditions of humidity and heat; the energy stored in the wood in the dry set state is released in a wet and hot environment, so that plastic deformation is recovered (commonly called compression rebound), so that the plastic deformation needs to be fixed by adopting a wet and hot fixing means in a manner of releasing the internal stress of the wood after compression densification treatment.
Based on the above findings, the inventors have overcome the prejudices of the prior art, and further found that the presence of moisture in wood is a major cause of problems of complicated control process, great control difficulty, relatively low success rate, etc. in the compression densification treatment of the prior art, but is not a necessary condition for softening and plastic deformation of wood.
In particular, the prior art recognizes that the softening of wood at high temperatures must occur under aqueous conditions, as a result of the transition of the wood from an elastic state to a plastic state, so that the wood can be compressed or bent. However, the transition from the elastic state to the plastic state is reversible, so that if there is no fixing treatment for plastic deformation, the wood will return to the pre-compression state to some extent or completely after the compression densification treatment conditions are eliminated.
The technical problem to be solved by the invention is to provide a wood strengthening treatment method aiming at the defects of the prior art, which can effectively solve at least one of the problems; the invention also provides a carbon material prepared by the treatment method.
An embodiment of the present invention provides a method for strengthening wood, wherein a treated material is compressed under a set treatment temperature and a set treatment pressure, the treated material is in an insulated state, and the treatment temperature is equal to or higher than a softening temperature of wood.
Preferably, the treatment temperature is 240 ℃ or higher.
Preferably, the treatment temperature is 240 ℃ to 280 ℃.
Preferably, the water content of the treatment material is 0±1.0%.
Preferably, in the compression direction of the treatment material, the treatment temperature is conducted from the heated side to the other side; at the same time, the process temperature progresses to the sub-thickness layer as the compression is fed.
Preferably, the process temperature is progressive with the feed of the compression, while the conduction, progressive of the process temperature enables the compression to continue the feed.
Preferably, the time taken from the first layer of unit thickness to reach the processing temperature to the last layer of unit thickness to complete compression is less than 5 minutes.
Preferably, the treated material is directly decompressed and discharged after reaching the set compression rate; or after depressurization, the product is discharged again after a thickness of 10s to 30 s.
Preferably, the set compression ratio is smaller than the actual compression ratio.
Preferably, the set compression ratio is 0 to 10% smaller than the actual compression ratio.
Another embodiment of the present invention provides a carbon material manufactured by the above wood strengthening treatment method, wherein the carbon material has an equilibrium moisture content of 7% to 9% in an environment of 20 ℃/95% rh.
Preferably, the carbon material self-prepares to shrink by 0 to 10% after cooling.
Preferably, the tree species from which the carbon material is made is red cone wood, mi Lao row wood, rubber wood, litchi wood, fir wood, pine wood, poplar wood, paulownia wood, western african sappan wood, eucalyptus wood or yellow beam wood.
In summary, compared with the prior art, the invention has the following beneficial effects:
1. the treatment temperature reaches the softening temperature of the wood, the wood can be compressed under the anhydrous condition, and the plastic deformation does not need to be fixed through an additional curing means, but is permanently fixed after the compression is finished, so the technical scheme of the invention can greatly shorten the treatment period and reduce the treatment energy consumption and the production cost.
2. The compression is carried out under the condition that the wood is anhydrous, the migration of moisture is not needed to be considered, and the pressure maintaining is not needed to release the internal pressure generated by the moisture, so that the design and the execution of the compression process are simple; and the conditions of rebound, bulge and burst at the moment of pressure relief caused by the improper pressure maintaining time can be avoided.
3. The processing temperature reaches the softening temperature of the wood and simultaneously finishes the softening of the wood to be compressed, and the progressive processing temperature and the feeding of the compression can be performed cooperatively, so that the efficiency of the compression processing can be further improved.
4. The treated material (or part of the thickness layer of the treated material) is still in a plastic state at the moment of pressure relief, the volume of the treated material (or part of the thickness layer of the treated material) reaching the set compression rate can be further contracted after pressure relief cooling, and the set compression rate is smaller than the actual compression rate in the process of operating the compression process, so that the energy consumption in the compression process can be reduced, and the production cost is reduced.
5. The invention only needs to control the compression temperature, and when the material temperature of the thickness layer of the treated material to be compressed is higher than the softening temperature of the wood, the compression deformation can occur, so the control of the compression process is very simple.
Detailed Description
In order to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below, and it is obvious that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, shall fall within the scope of the present application.
The embodiment of the application discloses a wood strengthening treatment method, which is a strengthening treatment means for compressing and plastically deforming a treatment material (such as red cone wood, mi Lao row wood, rubber wood, litchi wood, fir wood, pine wood, poplar wood, paulownia wood, western african sappan wood, eucalyptus wood or yellow beam wood) at a set treatment temperature and treatment pressure to obtain a densification effect. In particular, when the strengthening treatment is performed, the treatment material is in an absolute dry state, and the treatment temperature is equal to or higher than the softening temperature of the wood.
By the above method, the inventors creatively found that moisture is not one of the essential conditions for softening and plastic deformation of wood. Under the anhydrous condition (namely in a super-dry state), the wood can be softened only by heating the treatment material to the softening temperature of the wood, and then the softened wood can be subjected to plastic deformation by pressing, so that the strengthening treatment of the treatment material is realized in a compression densification mode. In contrast to the prior art, in this embodiment the effect of high temperature on the wood is to transform the wood from an elastomer to a plastomer, and the transformation process is not reversible. The plastic deformation caused by compression is irreversible because the wood is converted into a plastic body, so that the plastic deformation does not need to be fixed through an additional curing means, but is permanently fixed when the compression is finished, and the technical scheme of the embodiment can greatly shorten the treatment period and reduce the treatment energy consumption and the production cost. Meanwhile, the compression is carried out under the condition of no water of the wood, the migration of the moisture is not needed to be considered, and the pressure maintaining is not needed to release the internal pressure generated by the moisture, so that the design and the execution of the compression process are simple; and the conditions of rebound, bulge and burst at the moment of pressure relief caused by the improper pressure maintaining time can be avoided.
Specifically, the wood strengthening treatment method comprises a drying step and a compression densification step.
Drying, namely drying the treatment material to a balance weight at a temperature of 103-130 ℃ so as to keep the treatment material in an absolute dry state, for example 0+/-1.0%.
There are two embodiments of the step of compression densification.
The first embodiment is to compress the thickness layer (which may be a part of the thickness or the whole thickness of the treatment material) of the treatment material after the whole treatment material reaches the treatment temperature. Specifically, the heating member heats the processing material in an absolute state in a non-pressure state, the processing temperature is conducted from the heated side to the other side in the compression direction of the processing material until the whole thickness layer to be compressed reaches the processing temperature to soften, and then the pressure member presses the softened thickness layer to be compressed in the absolute state, so that the whole thickness layer to be compressed is plastically deformed. And if the thickness layer to be compressed is part of the thickness of the treatment material, preparing the carbon-wood composite profile, wherein the thickness layer subjected to compression reinforcement forms the carbon material layer in the composite profile, and the residual thickness layer not subjected to compression reinforcement forms the wood material layer in the composite profile. If the thickness layer to be compressed is the entire thickness of the treatment material, the carbon material, i.e. the carbon profile, is produced. The time taken from the start of heating by the heating means to the completion of the compression should be less than 5 minutes, in other words, the process of the compression treatment should be completed within 5 minutes.
The second embodiment is that the conduction, progression and feeding of the process temperature on the thickness layer to be compressed of the process material are performed in conjunction with the compression. Specifically, the pressure member applies pressure to the treatment material and compresses the thickness layer to be compressed in a portion reaching the treatment temperature, while the heating member is in contact with the surface of the treatment material or after the hot pressing member is in contact with the surface of the treatment material and before the entire thickness layer to be compressed reaches the treatment temperature. After the softened thickness layer is completed, the heating member transfers heat to and softens the sub-thickness layer below the completed compressed thickness layer, while the pressure member can continue to feed to compress the softened sub-thickness layer. In this process, the conduction of the process temperature is continuous, and the process temperature is advanced simultaneously with the feeding of the compression, and the compression can be continuously fed with the conduction and the advancement of the process temperature. The heat of the heating component can be transferred to the secondary thickness layer in a progressive mode besides the heat conduction mode, so that the temperature rise speed of the inner layer of the treatment material can be increased, and the compression efficiency is increased. Of course, the time taken from the start of heating by the heating means to the completion of compression should be less than 5 minutes.
The set compression ratio of the processing material is a compression ratio that can be achieved by setting the pressure member, and the actual compression ratio is a compression ratio that the processing material actually needs to achieve. In the technical scheme, the set compression rate is smaller than the actual compression rate.
As is well known to those skilled in the art, the porous structure of wood is such that the wet expansion and dry shrinkage rules dominate the dimensional and shape changes of the wood, while the thermal expansion and shrinkage rules have little or no effect on the dimensional and shape of the wood. However, in the present application, the transition from the elastomer to the plastomer occurs after the treated material in the absolute dry state is heated to the softening temperature of the wood, and the size of the wood in the plastomer state is mainly affected by the thermal expansion and contraction rule, but is affected only to a very small extent or hardly by the wet expansion and contraction rule. The treatment material is still in a plastic state at the moment of pressure relief, so that the treatment material can shrink in the pressure relief cooling process. Therefore, the set compression rate of the technical scheme is smaller than the actual compression rate, so that the energy consumption in the compression treatment process can be reduced to a certain extent, and the production cost is reduced.
The process of compressing and compacting the treated material is considered to be completed when the treated material reaches the set compression rate, and the pressure can be directly released and discharged after the treated material reaches the set compression rate, or the pressure can be released and discharged after the pressure is released and the thickness is maintained for 10 to 30 seconds, so that the carbon material (the carbon-wood composite section bar is prepared if the thickness layer to be compressed is part of the thickness of the treated material, and the prepared carbon material is the carbon section bar if the thickness layer to be compressed is the whole thickness of the treated material) is obtained. Finally, the water content of the carbon material is controlled to 6-8% under the conditions of 50-60 ℃ and 85-90% relative humidity. The equilibrium water content of the carbon material in the prepared carbon profile or carbon wood composite profile is 7-9% in the environment of 20 ℃/95% RH.
The technical scheme of the application is further described in the following specific examples. In the embodiment of the application, the drying treatment adopts a blast drying oven, the heating component and the pressure component of the compression treatment are flat plate type hot presses, and the water content of the prepared carbon-wood composite section or carbon section is controlled in a balance drying kiln.
Example 1
The treatment material is a poplar board with the thickness of 20mm, firstly, the treatment material is dried to balance weight at the temperature of 103+/-2 ℃, and the water content of the treatment material after drying is 0.5 to 1.0 percent.
Subsequently, the temperature of the upper and lower platens was raised to 250℃and the upper platen was stopped by limiting the pressing down using a gauge thickness of 19mm (i.e., the set compression ratio was 5%) and controlling the upper and lower platen spacing to 22mm.
And then, the treatment material is placed between an upper pressing plate and a lower pressing plate, the upper pressing plate is rapidly lowered to the surface of the upper pressing plate, which contacts the treatment material, and the pressure is applied after 90 seconds (preheating) of the contact of the upper pressing plate with the surface of the treatment material. In this embodiment, during the preheating process of 90s, the processing temperature is transferred to the thickness layer (i.e., the thickness layer to be compressed in this embodiment, the thickness is referred to the original thickness of the processing material) of about 0.9mm inward from the upper and lower surfaces of the processing material by heat conduction. After the pressing, the thick layer was compressed to form 2 carbon material layers (dense layers of the surface layer) having a thickness of about 0.4mm and respectively located on the upper and lower surfaces of the treated material, and a wood layer which was not reinforced by the compression was interposed between the two carbon material layers. In the compression process, the pressure of the pressing plate is 6MPa, the pressing speed of the upper pressing plate is 4mm/min, namely 15s can finish the compression process and reach the set compression rate, and the total processing time of the preheating time is 105s.
And then the flat plate type hot press is decompressed, the interval between the upper pressing plate and the lower pressing plate is still kept at 19mm, the press is opened to discharge after the thickness is kept for 10s, and the carbon-wood composite section bar with the total thickness of 18.98mm and the thickness of the carbon material layer of 0.38mm is prepared.
Finally, the water content of the carbon material part of the carbon-wood composite section bar is controlled to be 6-8% under the conditions of 50 ℃ and 85% of relative humidity.
Example 2
The treatment method of example 2 is substantially the same as that of example 1, except that the treatment temperature, the set compression ratio, the compression time consumption, and the like are different. Specifically, the thickness gauge has a thickness of 18mm, so the compression rate set in this example is 10%; the upper and lower platens were at 260℃and so the process temperature in this example was 260℃and the platen pressure was 5.5MPa. The upper platen is pressed while contacting the treatment material. In the compression process, the thickness layer of 0.01mm is assumed to be used as a unit thickness layer, when the pressing plate contacts the upper surface and the lower surface of the treatment material to enable the first unit thickness layer to reach the treatment temperature and soften, at the moment, the upper pressing plate can perform pushing feeding to compress the first unit thickness layer, the upper pressing plate and the lower pressing plate can be closer to the sub-thickness layer in the thickness layer subjected to compression along with pushing of the upper pressing plate (compression feeding), the treatment temperature also increases to the sub-thickness layer and enables the sub-thickness layer to soften, and then the upper pressing plate can continuously perform pushing feeding to compress the sub-thickness layer. And as the treatment temperature and the treatment pressure are gradually increased layer by layer, the compression treatment is finally finished after the set compression rate is reached. The pressing speed of the upper pressing plate is 2mm/min, so that the compression process can be completed for 60 seconds and the set compression rate can be achieved. The heat was transferred to the thickness layer of about 1.6mm inward from the upper and lower surfaces of the treated material (i.e., the thickness layer to be compressed in this example, the thickness being based on the thickness of the original treated material) at a treatment temperature of 60s, thereby forming 2 carbon material layers (dense surface layers) of about 0.6mm in thickness on the upper and lower surfaces of the treated material, respectively, with an uncompressed and reinforced wood layer therebetween.
In the embodiment, the press is opened to discharge after the thickness is kept for 20 seconds, and the total thickness of the carbon-wood composite section bar is 17.96mm and the thickness of the carbon layer is 0.58 mm.
Example 3
Example 3 was similar to the treatment material of example 1 and the treatment material was dried in the same manner, but the treatment temperature was 240℃and the thickness gauge was 17mm, so that the set compression amount was 15%.
The treatment material is placed between the upper pressing plate and the lower pressing plate, the upper pressing plate is rapidly lowered to the surface of the upper pressing plate, which is contacted with the treatment material, and then the upper pressing plate is kept (preheated) for 15s after being contacted with the surface of the treatment material, and the upper pressing plate continuously presses down and applies pressure to the treatment material. In this embodiment, in the compression direction, the processing temperature is first transferred from the upper and lower surfaces of the processing material toward the core layer side during the preheating process (heat conduction) as the contact time of the platen and the processing material continues, and then transferred continuously toward the sub-thickness layer on the core layer side as the contact time of the platen and the processing material continues and the pressing feed of the upper platen continues (heat conduction and heat progression occur simultaneously). In the compression process, the pressure of the pressing plate is 6MPa, the pressing speed of the upper pressing plate is 1mm/min, namely 180s can finish the compression process and reach the set compression rate. The treatment temperature can be transferred and increased to a thickness layer of about 2.4mm inward from the upper and lower surfaces of the treated material in the preheating and 180s compression process for 15s, so that 2 carbon material layers with the thickness of about 0.9mm respectively positioned on the upper and lower surfaces of the treated material are formed, and an uncompressed and reinforced wood layer is arranged between the two carbon material layers.
In this example, the press was opened to discharge after 30 seconds of thickness maintenance, and the total thickness of the carbon-wood composite profile was 17mm and the thickness of the carbon material layer was 0.9 mm.
Example 4
The treated material of this example was pine wood having a thickness of 20mm, the drying condition was 110.+ -. 2 ℃ and the moisture content of the balanced post-treated material was 0.2% to 0.5%. The treatment temperature was 250℃and the thickness of the gauge was 17mm, so that the set compression amount was 15%.
The treatment material is placed between the upper pressing plate and the lower pressing plate, the upper pressing plate is rapidly lowered to the surface of the upper pressing plate, which is contacted with the treatment material, and then the upper pressing plate is kept (preheated) for 30 seconds after being contacted with the surface of the treatment material, and the upper pressing plate continuously presses down and applies pressure to the treatment material. In the compression process, the pressure of the pressing plate is 6MPa, the pressing speed of the upper pressing plate is 1mm/min, namely 180s can finish the compression process and reach the set compression rate. The treatment temperature can be transferred and increased to a thickness layer of about 2.7mm inward from the upper and lower surfaces of the treated material in the preheating and 180s compression process for 30s, so that 2 carbon layers with the thickness of about 1.2mm respectively positioned on the upper and lower surfaces of the treated material are formed, and an uncompressed and reinforced wood layer is arranged between the two carbon material layers.
In the embodiment, the material is discharged directly after pressure relief, and the carbon-wood composite section bar with the thickness of 16.94mm and the thickness of 1.17mm of the carbon material layer is prepared.
Example 5
The treated material of this example was eucalyptus wood 16mm thick, the drying conditions were 110.+ -. 2 ℃ and the moisture content of the balanced post-treated material was 0.2% to 0.5%. The treatment temperature was 280℃and the thickness of the gauge was 13mm, so that the compression set was 18.7%.
The processing material is placed between the upper pressing plate and the lower pressing plate, the upper pressing plate is rapidly lowered to the surface of the upper pressing plate contacting the processing material, and the upper pressing plate is pressed while contacting the surface of the processing material. In the compression process, the pressure of the pressing plate is 5MPa, the pressing speed of the upper pressing plate is 2.5mm/min, namely 72s can finish the compression process and reach the set compression rate. The treatment temperature can be transferred and increased to the thickness layer with the thickness of about 2.5mm inwards on the upper surface and the lower surface of the treatment material in the compression process of 72s, so that 2 carbon material layers with the thickness of about 1.0mm respectively positioned on the upper surface and the lower surface of the treatment material are formed, and an uncompressed and reinforced wood layer is arranged between the two carbon material layers.
In the embodiment, after the thickness is kept for 15 seconds, the press is opened for discharging, and the carbon-wood composite section bar with the thickness of 12.86mm and the thickness of 0.93mm of the carbon material layer is prepared.
Example 6
The treatment material of this example was Mi Lao row wood with a thickness of 14mm, the drying condition was 110.+ -. 2 ℃ and the moisture content of the balanced post-treatment material was 0.2% to 0.5%. The treatment temperature was 250℃and the thickness of the gauge was 10mm, so that the compression set was 28.6%.
The processing material is placed between the upper pressing plate and the lower pressing plate, the upper pressing plate is rapidly lowered to the surface of the upper pressing plate, which contacts the processing material, and the upper pressing plate continuously presses down and applies pressure to the processing material while the upper pressing plate contacts the surface of the processing material. In the compression process, the pressure of the pressing plate is 6MPa, the pressing speed of the upper pressing plate is 2mm/min, namely 120s can finish the compression process and reach the set compression rate. The treatment temperature can be transferred to the thickness layer of about 4.3mm inward on the upper and lower surfaces of the treatment material in the compression process of 120s, so that 2 carbon material layers with the thickness of about 2.3mm respectively positioned on the upper and lower surfaces of the treatment material are formed, and an uncompressed and reinforced wood layer is arranged between the two carbon material layers.
In this example, after the thickness was maintained for 15 seconds, the press was opened to discharge, and a carbon-wood composite profile having a thickness of 9.96mm and a thickness of 2.28mm was produced.
Example 7
The treated material of this example was fir wood with a thickness of 12mm, the drying condition was 120.+ -. 2 ℃ and the moisture content of the balanced post-treated material was-0.2% to 0.2%. The treatment temperature was 260℃and the thickness of the gauge was 8mm, so that the set compression was 33.3%.
The processing material is placed between the upper pressing plate and the lower pressing plate, the upper pressing plate is rapidly lowered to the surface of the upper pressing plate, which contacts the processing material, and the upper pressing plate continuously presses down and applies pressure to the processing material while the upper pressing plate contacts the surface of the processing material. In the compression process, the pressure of the pressing plate is 5MPa, the pressing speed of the upper pressing plate is 2mm/min, namely 120s can finish the compression process and reach the set compression rate. The processing temperature can be transferred to the thickness layer of the whole processing material in the compression and heat progressive process of 120s, so that the processing effect of integral densification is formed.
In this example, the press was opened and discharged after maintaining the thickness for 15 seconds to prepare a carbon profile having a thickness of 7.9 mm.
Example 8
The treated material of this example was a fast-growing rubber wood having a thickness of 10mm, the drying condition was 120.+ -. 2 ℃ and the moisture content of the balanced post-treated material was-0.2% to 0.2%. The treatment temperature was 260℃and the thickness of the gauge was 6mm, so that the compression was set to 40%.
The processing material is placed between the upper pressing plate and the lower pressing plate, the upper pressing plate is rapidly lowered to the surface of the upper pressing plate, which contacts the processing material, and the upper pressing plate continuously presses down and applies pressure to the processing material while the upper pressing plate contacts the surface of the processing material. In the compression process, the pressure of the pressing plate is 5MPa, the pressing speed of the upper pressing plate is 2mm/min, namely 120s can finish the compression process and reach the set compression rate. The treatment temperature can be transferred to the thickness layer of the whole treatment material in the compression, heat conduction and heat progressive process of 120s, so that the treatment effect of integral densification is formed.
In this example, the press was opened and discharged after maintaining the thickness for 15 seconds to prepare a carbon profile having a thickness of 5.7 mm.
Example 9
The treated material of this example was tricuspid wood with a thickness of 10mm, the drying condition was 130.+ -. 2 ℃ and the water content of the balanced post-treated material was-1% to 0.5%. The treatment temperature was 280℃and the thickness of the gauge was 6mm, so that the compression was set to 40%.
The treatment material is placed between the upper pressing plate and the lower pressing plate, the upper pressing plate is rapidly lowered to the surface of the upper pressing plate, which is contacted with the treatment material, and then the upper pressing plate is kept (preheated) for 30 seconds after being contacted with the surface of the treatment material, and the upper pressing plate continuously presses down and applies pressure to the treatment material. In the compression process, the pressure of the pressing plate is 7MPa, and the pressing speed of the upper pressing plate is 3mm/min, namely 80s can finish the compression process and reach the set compression rate. The treatment temperature can be transferred to the thickness layer of the whole treatment material in the processes of 30s preheating, 80s compression, heat conduction and heat progressive, so that the treatment effect of integral densification is formed.
In the embodiment, the carbon section bar with the thickness of 5.6mm is prepared by discharging directly after pressure relief.
Example 10
The treated material of this example was fir wood with a thickness of 8mm, the drying condition was 130.+ -. 2 ℃ and the moisture content of the balanced post-treated material was-1% to 0.5%. The treatment temperature was 260℃and the thickness of the gauge was 4.5mm, so that the compression set was 43.7%.
The treatment material is placed between the upper pressing plate and the lower pressing plate, the upper pressing plate is rapidly lowered to the surface of the upper pressing plate, which is contacted with the treatment material, and then the upper pressing plate is kept (preheated) for 60 seconds after being contacted with the surface of the treatment material, and the upper pressing plate continuously presses down and applies pressure to the treatment material. In the compression process, the pressure of the pressing plate is 7MPa, the pressing speed of the upper pressing plate is 2mm/min, namely 106s can finish the compression process and reach the set compression rate. The treatment temperature can be transferred to the thickness layer of the whole treatment material in the processes of 60s preheating, 106s compression, heat conduction and heat progressive, so that the treatment effect of integral densification is formed.
In the embodiment, the carbon section bar with the thickness of 4.3mm is prepared by discharging directly after pressure relief.
Example 11
The treated material of this example was poplar 6mm thick, the drying condition was 130.+ -. 2 ℃ and the moisture content of the balanced post-treated material was-1% to 0.5%. The treatment temperature was 270℃and the gauge thickness was 3.5mm, so that the compression set was 41.7%.
The treatment material is placed between the upper pressing plate and the lower pressing plate, the upper pressing plate is rapidly lowered to the surface of the upper pressing plate, which is contacted with the treatment material, and then the upper pressing plate is kept (preheated) for 60 seconds after being contacted with the surface of the treatment material, and the upper pressing plate continuously presses down and applies pressure to the treatment material. In the compression process, the pressure of the pressing plate is 7MPa, the pressing speed of the upper pressing plate is 4mm/min, namely 38s can finish the compression process and reach the set compression rate. The treatment temperature can be transferred to the thickness layer of the whole treatment material in the processes of 60s preheating, 38s compression, heat conduction and heat progressive, so that the treatment effect of integral densification is formed.
In the embodiment, the carbon section bar with the thickness of 3.27mm is prepared by discharging directly after pressure relief.
Example 12
The treated material of this example was litchi wood with a thickness of 6mm, the drying condition was 103.+ -. 2 ℃ and the moisture content of the balanced post-treated material was 0% to 0.5%. The treatment temperature was 280℃and the thickness of the gauge was 5mm, so that the compression set was 16.7%.
The treatment material is placed between the upper pressing plate and the lower pressing plate, the upper pressing plate is rapidly lowered to the surface of the upper pressing plate, which is contacted with the treatment material, and then the upper pressing plate is kept (preheated) for 60 seconds after being contacted with the surface of the treatment material, and the upper pressing plate continuously presses down and applies pressure to the treatment material. In the compression process, the pressure of the pressing plate is 9MPa, and the pressing speed of the upper pressing plate is 1mm/min, namely 60s can finish the compression process and reach the set compression rate. The treatment temperature can be transferred to the thickness layer of the whole treatment material in the processes of 60s preheating, 60s compression, heat conduction and heat progressive, so that the treatment effect of integral densification is formed.
In the embodiment, the carbon section bar with the thickness of 4.92mm is prepared by discharging directly after pressure relief.
The production parameters of the wood strengthening treatment methods of examples 1 to 6 are shown in table 1; the production parameters of the wood strengthening treatment methods of examples 7 to 12 are shown in table 2; the product performance parameters of the carbon-wood composite profiles produced by the wood strengthening treatment methods of examples 1 to 6 are shown in table 3; the product performance parameters of the carbon profiles produced by the wood strengthening treatment methods of examples 7 to 12 are shown in table 4. Wherein, the control groups 1 and 2 are surface layer densification sectional materials prepared by the surface layer compression technology in the prior art, and the control groups 3 and 4 are integral densification sectional materials prepared by the integral compression technology in the prior art. The compression process is implemented by adopting a flat plate type hot press, and the compression treatment temperature is 160 ℃; the plastic deformation fixing method adopts normal pressure superheated steam treatment, and the treatment temperature is 180 ℃.
TABLE 1 production parameters of the methods for the strengthening treatment of Wood of examples 1 to 6
TABLE 2 production parameters of the methods for strengthening Wood treatment of examples 7 to 11
TABLE 3 product Performance parameters of carbon-wood composite profiles obtained by the Wood strengthening treatment method of examples 1 to 6
TABLE 4 product Performance parameters of carbon-wood composite Profiles produced by the Wood strengthening treatment methods of examples 7 to 11
The foregoing description is for purposes of illustration and is not intended to be limiting. Many embodiments and many applications other than the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the present teachings should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated herein by reference for the purpose of completeness. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to forego such subject matter, nor should the applicant be deemed to have such subject matter not considered to be part of the subject matter of the disclosed application.
Claims (7)
1. A method for strengthening wood, wherein the treated wood is compressed under the conditions of a set treatment temperature and a set treatment pressure, characterized in that the treated wood is in an absolute dry state, and the treatment temperature is equal to or higher than a wood softening temperature; in the compression direction of the treatment material, the treatment temperature is conducted from the heated side to the other side; at the same time, the process temperature progresses to the sub-thickness layer as the compression is fed; the set compression rate is smaller than the actual compression rate; the time taken from the first layer of unit thickness to reach the processing temperature to the last layer of unit thickness to complete compression is less than 5 minutes.
2. The method of strengthening wood according to claim 1, wherein the treatment temperature is 240 ℃ or higher.
3. The method for strengthening wood according to claim 1, wherein the water content of the treated material is 0±1.0%.
4. The method of claim 1, wherein the treatment temperature is increased as the compression is fed, while the compression is allowed to continue as the treatment temperature is conducted.
5. The method for strengthening wood according to claim 1, wherein the treated wood is discharged after reaching a set compression rate by direct pressure relief; or after depressurization, the product is discharged again after a thickness of 10s to 30 s.
6. A carbon material produced by the method for strengthening wood according to claim 1, wherein the carbon material has an equilibrium moisture content of 7% to 9% in an environment of 20 ℃/95% rh.
7. The carbon material as claimed in claim 6, wherein the tree species from which the carbon material is made is red cone wood, mi Lao row wood, fast-growing rubber wood, fir wood, pine wood, poplar wood or eucalyptus wood.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210767327.6A CN115139380B (en) | 2022-06-30 | 2022-06-30 | Wood strengthening treatment method and carbon material thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210767327.6A CN115139380B (en) | 2022-06-30 | 2022-06-30 | Wood strengthening treatment method and carbon material thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115139380A CN115139380A (en) | 2022-10-04 |
| CN115139380B true CN115139380B (en) | 2023-05-09 |
Family
ID=83410617
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210767327.6A Active CN115139380B (en) | 2022-06-30 | 2022-06-30 | Wood strengthening treatment method and carbon material thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115139380B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03293120A (en) * | 1990-04-11 | 1991-12-24 | Yamau:Kk | Manufacture of wood block |
| 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 |
| CN110666912A (en) * | 2019-09-24 | 2020-01-10 | 南京林业大学 | Method for preparing compact wood through synergistic effect of chemical pretreatment and hot pressing |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5002713A (en) * | 1989-12-22 | 1991-03-26 | Board Of Control Of Michigan Technological University | Method for compression molding articles from lignocellulosic materials |
| WO2002102560A1 (en) * | 2001-06-15 | 2002-12-27 | The University Of Melbourne | Boron-based wood preservatives and treatment of wood with boron-based preservatives |
| JP4680745B2 (en) * | 2005-10-21 | 2011-05-11 | マイウッド・ツー株式会社 | Surface plastic working wood manufacturing method |
| CN101214675B (en) * | 2008-01-08 | 2011-01-19 | 涂登云 | Timber wood hot pressing charing intensification method |
| US7836924B2 (en) * | 2009-01-16 | 2010-11-23 | Weyerhaeuser NR Comp½any | Methods for enhancing hardness and dimensional stability of a wood element and wood product having enhanced hardness |
| CN102554992B (en) * | 2010-12-30 | 2014-09-17 | 广州好莱客创意家居股份有限公司 | Surface enhanced type wood section bar and manufacturing method thereof |
| CN103753664B (en) * | 2013-02-04 | 2016-08-31 | 中国林业科学研究院木材工业研究所 | A kind of compressed wood and preparation method thereof |
| CN103481348B (en) * | 2013-09-04 | 2015-02-25 | 华南农业大学 | Integral reinforced solid wood section bar and manufacturing method thereof |
| 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 |
| CN108582378A (en) * | 2018-03-29 | 2018-09-28 | 华南农业大学 | A kind of unilateral side surface layer compressed wood and preparation method thereof |
| CN108582377B (en) * | 2018-03-29 | 2021-01-19 | 华南农业大学 | Method for integrating wood compression and in-situ hot treatment under pressure and compressed wood prepared by method |
| CN114147827A (en) * | 2021-12-14 | 2022-03-08 | 黄荣凤 | Solid wood layered compression method based on moisture distribution regulation and control |
-
2022
- 2022-06-30 CN CN202210767327.6A patent/CN115139380B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03293120A (en) * | 1990-04-11 | 1991-12-24 | Yamau:Kk | Manufacture of wood block |
| 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 |
| WO2020029507A1 (en) * | 2018-08-07 | 2020-02-13 | 中国林业科学研究院木材工业研究所 | Method for producing density distribution-controllable compressed and densified solid wood panel |
| CN110666912A (en) * | 2019-09-24 | 2020-01-10 | 南京林业大学 | Method for preparing compact wood through synergistic effect of chemical pretreatment and hot pressing |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115139380A (en) | 2022-10-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108582377B (en) | Method for integrating wood compression and in-situ hot treatment under pressure and compressed wood prepared by method | |
| US4393019A (en) | Method of pressing reconstituted lignocellulosic materials | |
| KR100473602B1 (en) | Method for making composite board using phenol formaldehyde binder | |
| CN108943208B (en) | A kind of solid wood compression compact sheet production method that Density Distribution is controllable | |
| KR100341872B1 (en) | How to Manufacture Ringo Cellulose Boards | |
| CN108724392B (en) | Preparation method of curved solid wood | |
| CN106584634B (en) | A kind of timber surface layer compression method and its timber surface layer staypak | |
| CN109366656B (en) | Control method for density peak shape of single-side compressed wood | |
| EP1824660B1 (en) | Method for deforming a thermosetting plate | |
| CN115139380B (en) | Wood strengthening treatment method and carbon material thereof | |
| CN105034092A (en) | Efficient production method for cold-pressed recombined bamboo timber | |
| CN115319877B (en) | Timber surface densification treatment method | |
| JP4034343B2 (en) | Method for producing lignocellulose board | |
| CN108638273A (en) | A kind of unilateral side surface layer compressed wood and preparation method thereof | |
| CN114851322B (en) | Hot pressing method for continuous flat-pressing thick artificial board | |
| CN113103389B (en) | Processing equipment and method for bamboo bending piece | |
| CN108673689A (en) | A kind of unilateral side surface layer compressed wood and preparation method thereof | |
| JP3131605B2 (en) | Method for manufacturing compressed wood | |
| CA2100131A1 (en) | Method and apparatus for making pressed articles from wood | |
| JPH09155814A (en) | Compressed wooden material and production thereof | |
| CN116533340B (en) | Preparation method of compressed wood with controllable density | |
| CN114311201B (en) | High-frequency hot-pressing drying method for wood | |
| JPH09155819A (en) | High-density ligneous material and its manufacture | |
| JP3062368B2 (en) | Wood material heat treatment method | |
| RU2191686C1 (en) | Dry wood compaction method |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |