CN108724392B - Preparation method of curved solid wood - Google Patents
Preparation method of curved solid wood Download PDFInfo
- Publication number
- CN108724392B CN108724392B CN201810578794.8A CN201810578794A CN108724392B CN 108724392 B CN108724392 B CN 108724392B CN 201810578794 A CN201810578794 A CN 201810578794A CN 108724392 B CN108724392 B CN 108724392B
- Authority
- CN
- China
- Prior art keywords
- wood
- treatment
- microwave treatment
- microwave
- adhesive
- 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
- 239000002023 wood Substances 0.000 title claims abstract description 184
- 239000007787 solid Substances 0.000 title claims abstract description 68
- 238000002360 preparation method Methods 0.000 title claims abstract description 17
- 238000005452 bending Methods 0.000 claims abstract description 56
- 239000000853 adhesive Substances 0.000 claims abstract description 44
- 230000001070 adhesive effect Effects 0.000 claims abstract description 44
- 238000000034 method Methods 0.000 claims abstract description 24
- 238000003825 pressing Methods 0.000 claims abstract description 15
- 238000007493 shaping process Methods 0.000 claims abstract description 13
- 238000004519 manufacturing process Methods 0.000 claims abstract description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 32
- 238000005470 impregnation Methods 0.000 claims description 21
- 238000012545 processing Methods 0.000 claims description 10
- 238000007598 dipping method Methods 0.000 claims description 8
- XPFVYQJUAUNWIW-UHFFFAOYSA-N furfuryl alcohol Chemical compound OCC1=CC=CO1 XPFVYQJUAUNWIW-UHFFFAOYSA-N 0.000 claims description 8
- 230000006835 compression Effects 0.000 claims description 7
- 238000007906 compression Methods 0.000 claims description 7
- 229920002774 Maltodextrin Polymers 0.000 claims description 6
- 239000005913 Maltodextrin Substances 0.000 claims description 6
- 229940035034 maltodextrin Drugs 0.000 claims description 6
- 241000219000 Populus Species 0.000 claims description 5
- 229920002531 Rubberwood Polymers 0.000 claims description 5
- 235000008577 Pinus radiata Nutrition 0.000 claims description 4
- 241000218621 Pinus radiata Species 0.000 claims description 4
- 238000010438 heat treatment Methods 0.000 claims description 4
- 229920006395 saturated elastomer Polymers 0.000 claims description 3
- 239000004115 Sodium Silicate Substances 0.000 claims description 2
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 claims description 2
- 229910052911 sodium silicate Inorganic materials 0.000 claims description 2
- 239000007864 aqueous solution Substances 0.000 claims 1
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 30
- 238000001035 drying Methods 0.000 description 13
- 230000000694 effects Effects 0.000 description 9
- 239000000463 material Substances 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 230000008569 process Effects 0.000 description 7
- 239000000047 product Substances 0.000 description 7
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 description 6
- 238000000465 moulding Methods 0.000 description 6
- 229920001568 phenolic resin Polymers 0.000 description 6
- 239000005011 phenolic resin Substances 0.000 description 6
- 230000001007 puffing effect Effects 0.000 description 5
- 239000007849 furan resin Substances 0.000 description 4
- 241000894007 species Species 0.000 description 4
- 238000004026 adhesive bonding Methods 0.000 description 3
- 230000000295 complement effect Effects 0.000 description 3
- 210000001145 finger joint Anatomy 0.000 description 3
- 229920005862 polyol Polymers 0.000 description 3
- 150000003077 polyols Chemical class 0.000 description 3
- 238000010998 test method Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 238000002791 soaking Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 241000208140 Acer Species 0.000 description 1
- 235000017166 Bambusa arundinacea Nutrition 0.000 description 1
- 235000017491 Bambusa tulda Nutrition 0.000 description 1
- 240000000731 Fagus sylvatica Species 0.000 description 1
- 235000010099 Fagus sylvatica Nutrition 0.000 description 1
- 241000565391 Fraxinus mandshurica Species 0.000 description 1
- 240000008669 Hedera helix Species 0.000 description 1
- 229920002488 Hemicellulose Polymers 0.000 description 1
- 229920000877 Melamine resin Polymers 0.000 description 1
- 244000082204 Phyllostachys viridis Species 0.000 description 1
- 235000015334 Phyllostachys viridis Nutrition 0.000 description 1
- 241000219492 Quercus Species 0.000 description 1
- 241001106462 Ulmus Species 0.000 description 1
- 229920001807 Urea-formaldehyde Polymers 0.000 description 1
- 238000007605 air drying Methods 0.000 description 1
- 239000011425 bamboo Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 238000010411 cooking Methods 0.000 description 1
- 238000005034 decoration Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229920005610 lignin Polymers 0.000 description 1
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 229920005615 natural polymer Polymers 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000010025 steaming Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000010875 treated wood Substances 0.000 description 1
- 238000009489 vacuum treatment Methods 0.000 description 1
- 229940045860 white wax Drugs 0.000 description 1
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
- B27K5/003—Treating of wood not provided for in groups B27K1/00, B27K3/00 by using electromagnetic radiation or mechanical waves
- B27K5/0055—Radio-waves, e.g. microwaves
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27H—BENDING WOOD OR SIMILAR MATERIAL; COOPERAGE; MAKING WHEELS FROM WOOD OR SIMILAR MATERIAL
- B27H1/00—Bending wood stock, e.g. boards
-
- 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
- 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
- B27K3/10—Apparatus
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Forests & Forestry (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Chemical And Physical Treatments For Wood And The Like (AREA)
Abstract
The invention discloses a preparation method of curved solid wood, which comprises the following steps: carrying out microwave treatment on wood with the power of 5kW to 300 kW; impregnating the wood subjected to microwave treatment through an adhesive; carrying out mould pressing bending treatment on the impregnated wood; and shaping the wood subjected to the mould pressing bending treatment to obtain the bent solid wood. The tree species which can be treated by the method is not limited, and the prepared curved solid wood has low rebound rate, high yield, short production period, density, hardness and strength which all reach the performance of the conventional curved solid wood in the market, controllable product performance, adjustable curvature, designable structure, attractive appearance and good decorative performance.
Description
Technical Field
The invention relates to the field of wood processing, in particular to a preparation method of curved solid wood.
Background
The wood is a natural polymer composite material, and the product has various excellent properties of nature, environmental protection, beautiful appearance and the like. However, wood itself is poor in plasticity, and is easily damaged when being processed (bent or molded) into various complicated shapes, and it is difficult to satisfy the demands of people for the modeling and quality of wooden products.
In order to avoid the defect of poor plasticity of wood, most of bending members for furniture in the market at present are veneer gluing bending members and finger joints, but the veneer gluing bending members have weak solid woodiness, and the finger joints influence the overall aesthetic feeling. With the continuous improvement of the consumption level and the aesthetic appearance of people, the veneer glued bending member and finger joint material can not meet the demands of people, and the bending solid wood with solid wood texture is more and more popular.
The main preparation methods of the existing bending solid wood comprise sawing bending and steaming. The sawing and bending waste a large amount of wood, the wood utilization rate is low, and the production cost of enterprises is greatly improved. The cooking method has long processing time and is suitable for processing flexible hard broad-leaved wood, such as fraxinus mandshurica, white wax rod, beech, elm, oak, maple and the like, and the types of the wood which can be processed are limited. Further, the yield of the flexible hard broad-leaved wood is lower and lower, and the flexible hard broad-leaved wood gradually becomes a precious wood for tree species, so that the production cost of the curved solid wood produced by the method is higher.
Conventional environmental-friendly curved solid wood processing techniques include low-power microwave methods. The low-power microwave method is a softening treatment method in the preparation of curved solid wood by utilizing microwave heating, and a technology for softening wood by utilizing microwaves exists in the prior art, but the size of the wood which can be treated is smaller, and the softening treatment effect is not ideal for the wood which is not easy to bend, such as fast-growing wood and the like, so that the subsequent bending effect cannot reach expectations, and the defects of finished products are more.
Disclosure of Invention
In view of the problems in the prior art, the invention aims to provide a preparation method of curved solid wood, which is characterized in that the moisture content of wood is controlled, and the wood is treated by microwaves with the power of 5kW to 300kW and then impregnated with an adhesive, so that the tree species which can be treated by the method is not limited, and the prepared curved solid wood has the advantages of low rebound rate, high yield, short production cycle, short density, hardness and strength, and achieves the performances of the conventional curved solid wood in the market, controllable product performance, adjustable bending degree, designable structure, attractive appearance and good decorative performance.
In one aspect, the present invention provides a method for preparing curved solid wood, comprising:
carrying out microwave treatment on wood with the power of 5kW to 300 kW;
impregnating the wood subjected to microwave treatment through an adhesive;
carrying out mould pressing bending treatment on the impregnated wood; and
shaping the wood subjected to the mould pressing bending treatment to obtain the bent solid wood.
The inventor of the application processes the wood by adopting microwaves with the power of 5kW to 300kW, and the higher microwave power can cause the inside of the wood to form steam pressure difference to destroy the weak area of the wood, so that the wood rapidly forms a large number of uniform cracks, the uniform cracks further form permeation channels, and finally the puffing of the wood is finished, and as a result, the permeation channels improve the permeability of the wood, and the introduction of adhesives and subsequent dipping treatment are facilitated; meanwhile, the stress in the wood is released in the puffing process, and the microwave treatment also realizes the preliminary softening of the wood, so that the subsequent mould pressing bending treatment is effectively carried out.
Furthermore, the wood subjected to microwave treatment is subjected to dipping treatment through the adhesive, so that cracks generated during the microwave treatment can be glued, the density, hardness and strength of the wood are improved, and the rebound of the bent wood can be prevented in the subsequent shaping treatment, so that the rebound rate of the bent solid wood is reduced.
The application can more effectively carry out mould pressing bending treatment through the cooperation of microwave treatment and dipping treatment, and even the wood type which is not easy to bend can reach expected bending effect, thereby expanding the application range of the application.
According to the present invention, the apparatus for performing the microwave treatment is not limited, and examples thereof include tunnel type microwave treatment wood equipment, box type microwave treatment wood equipment, and kiln type microwave treatment wood equipment. The tunnel type microwave wood treatment equipment is preferred in the invention because of higher production efficiency of the tunnel type microwave wood treatment equipment.
In a preferred embodiment of the present invention, the microwave frequency of the microwave treatment is 100MHz to 5GHz, preferably 200MHz to 2450MHz, more preferably 433MHz to 915MHz; the microwave treatment time is 10s to 1200s, preferably 20s to 600s, more preferably 20s to 300s; the temperature of the microwave treatment is 100-180 ℃, preferably 100-130 ℃.
According to the present invention, it is preferable to perform microwave treatment on wood using a microwave frequency of 433MHz to 915MHz, because the inventors of the present application have found in the study that by controlling the microwave frequency within a specific range, it is possible to maximize dielectric loss of wood and to convert electric energy into heat energy with high efficiency, and as a result, the wood heating and puffing treatment effects are optimal.
In another preferred embodiment of the present invention, the adhesive is selected from at least one of a phenolic resin adhesive, a polyol adhesive, a urea resin adhesive, a furan resin adhesive, a melamine adhesive, and an inorganic adhesive, preferably at least one of a phenolic resin adhesive, a polyol adhesive, a furan resin adhesive, and an inorganic adhesive, more preferably at least one of a maltodextrin adhesive as a polyol adhesive, a furfuryl alcohol resin as a furan resin adhesive, and an aqueous sodium silicate solution as an inorganic adhesive. In addition, the solid content of the adhesive is 10% -100%, preferably 20% -60%, and more preferably 20% -50%.
According to the invention, the adhesive is used in an amount of 20-50 parts by weight based on 100 parts by weight of the wood, and a good impregnation effect can be achieved at this ratio.
According to the invention, the adhesive has the characteristics of low viscosity, easiness in impregnation, low formaldehyde release amount and the like, so that the adhesive can saturate the treated wood in a short impregnation time, and the formaldehyde release amount of the finally prepared bent solid wood meets E0 or E1 release requirements.
In another preferred embodiment of the present invention, the impregnation treatment employs a vacuum pressurized impregnation method comprising introducing an adhesive under vacuum conditions, and completing the impregnation treatment under pressurized conditions, wherein the vacuum conditions provide a pressure of-0.1 MPa to-0.05 MPa, and the pressurized conditions provide a pressure of 0.5MPa to 2.0MPa, preferably 1.0MPa to 2.0 MPa.
According to the invention, since the wood has a porous structure and a large number of uniform cracks are generated after the microwave treatment, the air in the porous structure of the wood can be discharged through the vacuum treatment, and the adhesive can be immersed into the wood more quickly and uniformly. On the other hand, by the pressure treatment, the adhesive can be sufficiently impregnated with the wood to achieve a better impregnation effect.
According to the invention, the impregnation treatment is carried out in a vacuum pressurized impregnation tank fitted with a vacuum pump.
According to the invention, the time of the impregnation treatment can be selected according to the sample size, preferably, the impregnation time is correspondingly increased by 10-20 min every 1mm increase in the thickness of the wood.
In another preferred embodiment of the present invention, the press bending treatment comprises controlling the moisture content of the impregnated wood to 20% -60%, placing the impregnated wood in a press, and performing the press bending treatment, preferably, the press bending treatment conditions comprise: the temperature is 100-150 ℃, the compression ratio is 5-50%, the pressure is 5-30 MPa, and the treatment time is 20-60 min.
According to the present invention, by controlling the water content within the above range, it is advantageous to save energy consumption and achieve a balance of the relationship between the molding temperature and the molding bending time.
In another preferred embodiment of the present invention, the press bending treatment includes softening the impregnated wood in advance, and then placing the wood in a press, and the press bending treatment is performed, preferably, the press bending treatment conditions include: the heating is not carried out, the compression rate is 5-50%, the pressure is 5-30 MPa, and the treatment time is 3-60 min.
According to the present invention, the water content determines the softening point and softening effect of the wood, and therefore, it is preferable to control the water content of the wood before the softening treatment. The numerical range of the water content is related to the process of the selected softening treatment, and therefore, it is preferable to adjust the water content depending on the softening process. For example, when the softening treatment is performed by superheated steam, the water content may be controlled to be lower than 40%, whereas when the softening treatment is performed by a microwave or a high-frequency electric field, the water content needs to be controlled to be 20% -60%. By this operation, it is possible to achieve an optimal softening effect of the wood in a minimum time, while reducing the processing time and the reject rate for the subsequent molding step.
In another preferred embodiment of the present invention, the softening treatment with superheated steam comprises contacting the impregnated wood with saturated steam at 100 to 150 ℃ for 20 to 60 minutes after controlling the water content of the impregnated wood to be less than 40%.
According to the invention, the moulding press comprises a female die, a male die complementary to the female die, and pressure means for providing pressure to the male die, the male die being complementary to the female die by means of the pressure means, whereby the wood between the female die and the male die is bent, the male die being fixed to the female die after the moulding bending process has been completed.
According to the invention, the male mould comprises a base plate (1) and a male curved surface piece (2) detachably arranged on the base plate, and the female mould comprises a female curved surface piece (3) complementary to the male curved surface piece. Preferably, baffles (4) are provided on both sides of the female die in the width direction of the wood, the baffles being used to prevent the wood from sliding relative to the female die during the press bending process.
In another preferred embodiment of the invention, the moisture content of the wood before the microwave treatment is 20% to 100%, preferably 20% to 70%.
The inventors of the present application found in the study that the effect of the microwave treatment was affected by the moisture content of the wood before the microwave treatment. Since water molecules have a stronger polarity than other molecules (e.g., cellulose molecules, hemicellulose molecules, and lignin molecules) when wood is treated with microwaves, it is one of the best mediums to absorb microwaves. During microwave treatment, microwaves directly act on water molecules of the medium to convert electric energy into heat energy. Meanwhile, the penetrating performance of microwaves is good, so that the wood can be heated while the inside and the outside of the wood are finished under the condition that heat conduction is not carried out, but the inside temperature of the wood is higher than the outside temperature due to the lack of heat dissipation conditions, so that temperature gradient distribution is formed, and then the inside water molecules are driven to permeate to the surface of the wood, so that steam pressure difference is formed. When the steam pressure difference reaches a certain value, the weak area of the wood is directly damaged, a large number of uniform cracks are formed, the uniform cracks further form a penetration channel, and finally the puffing of the wood is finished. Based on the method, from the perspective of obtaining a better puffing effect, the moisture content of the wood before microwave treatment is controlled to be 20-100%.
In addition, the wood types before microwave treatment are different, and the required water content is also different. For example, the moisture content required for radiata pine is 60% -70%; the water content of the rubber wood is required to be 20% -30%; whereas poplar is required to have a moisture content of 40% -50%.
According to the present invention, when the moisture content of the wood is higher than the required range, the moisture content of the wood can be reduced by means of drying treatment or the like; when the water content is lower than the required range, the water content of the wood can be increased by means of soaking in water or the like (soaking under normal pressure or vacuum pressure).
According to the invention, the shaping treatment comprises kiln dry shaping, natural gas dry shaping, high-frequency drying shaping and the like. By way of example, kiln drying involves feeding the compression-molded wood together with a mould into a drying kiln and drying at a temperature of 60-70 ℃ for 10-40 hours. The shaping treatment can ensure that the bending deformation of the wood is completely fixed.
In yet another aspect, the present invention provides curved solid wood prepared according to the above-described preparation method.
In another preferred embodiment of the present invention, the moisture content of the curved solid wood is 8% to 20%.
According to the invention, the curved solid wood can be applied to the fields of furniture, artware carving, outdoor decorative materials and the like.
Compared with the log, the bending solid wood prepared by the preparation method has the advantages of density increased by more than 30%, hardness increased by more than 300N, bending strength over 70MPa, bending degree adjustable within the range of 1:3-1:2, rebound rate of only 5% -10%, yield up to more than 85%, short production period and low production cost.
Drawings
FIG. 1 shows a process flow diagram of the preparation method of the present invention.
Fig. 2 shows an exemplary diagram of a mold used in an embodiment of the present invention.
Fig. 3 shows a picture of the curved solid wood produced in example 1.
Fig. 4 shows a picture of the curved solid wood produced in example 3.
Reference numerals: 1-a substrate; 2-a convex curved surface sheet; 3-concave curved surface sheet; 4-baffle
Detailed Description
The present invention will be described in detail with reference to examples, but the scope of the present invention is not limited to the following description.
The curved solid wood prepared in examples 1 to 3 and comparative examples 1 to 4 was subjected to performance test according to the following method or standard.
Density: the test was performed according to GB/T1933-2009 method for wood density determination.
Hardness: the test was performed according to GB/T1941-2009 wood hardness test method.
Flexural strength: the bending strength test method is carried out according to GB/T1936.1-2009 wood bending strength test method, but the bending solid wood is changed from the convex surface to the concave surface to contact the end part of the pressing head.
Formaldehyde emission level: the test was carried out according to GB 18580-2017 on the release limit of formaldehyde in interior decoration materials, artificial boards and products thereof.
The curved solid wood prepared in examples 1 to 3 and comparative examples 1 to 4 was calculated according to the following formula.
In the above formula (2), the finished product refers to a curved solid wood which is not broken or has no obvious cracks after bending, and the waste product refers to a curved solid wood which is broken or has obvious cracks after bending. According to the present invention, the yields in examples 1 to 3 and comparative examples 1 to 4 below were measured at a bending degree of the bent solid wood of 1:6.
In the above formula (4), the "radius of curvature after rebound" in the rebound rate is measured after immersing the curved solid wood in water at 60 ℃ for 4 hours, and the "radius of curvature in the mold after molding" means the radius of curvature of the curved solid wood when the curved solid wood is taken out from the mold and directly measured or completely curved, which is equivalent to the radius of curvature of the curved mold.
In examples 1 to 3 and comparative examples 1 to 4, the maximum bending degree means a maximum bending degree capable of realizing a yield of bending solid wood of 95% or more.
Reagents used hereinafter include but are not limited to,
name of phenolic resin adhesive: phenolic resin for restructured bamboo impregnation, model: 16L510.
Furfuryl alcohol resin name: high-strength furfuryl alcohol type furan resin, model: HY.
The maltodextrin adhesive is prepared by blending industrial grade maltodextrin.
Example 1
A. Wood selection and preliminary processing
Selecting Pinus radiata (imported in New Zealand is one of artificial forest wood species and also one of main imported wood species in China)For the wood to be processed, the radiation bulk density used in this example was 0.44g/cm 3 The hardness was 2100N, which was processed into 400mm (length). Times.120 mm (width). Times.30 mm (thickness) wood, and the moisture content of the wood was controlled to be 60% -70%.
B. Preparation of curved solid wood
Microwave treatment: the timber is placed in tunnel type high-power microwave treatment timber equipment (the length of a microwave cavity is 0.5 m) for microwave treatment, the frequency of the microwave treatment is 915MHz, the power of the microwave treatment is 140kW, the material transmission speed is 1.4m/min (which is equivalent to the time of the microwave treatment being 21.4 s), and the temperature of the microwave treatment is 130 ℃.
Dipping treatment: the adhesive is phenolic resin adhesive with solid content of 30%. The timber is put into a vacuum hydraulic impregnating tank for impregnating treatment, the vacuum degree is controlled to be-0.08 MPa, then phenolic resin adhesive is injected into the vacuum hydraulic impregnating tank, and the pressure in the vacuum hydraulic impregnating tank is increased until the pressure reaches 1.5MPa.
And (3) mould pressing bending: after the moisture content of the impregnated wood was controlled to 40% by drying, it was placed in a mold of a hot press preheated to 130 c, and hot pressed for 30 minutes under conditions of a temperature of 130 c, a compression ratio of 20% and a pressure of 25MPa, to bend the wood into a desired shape.
Shaping: and taking the bent solid wood with the die out of the hot press, conveying the bent solid wood into a shaping drying kiln, and drying the bent solid wood for 24 hours at the temperature of 60 ℃. Taking out the curved solid wood from the mould to obtain the curved solid wood with the density of 0.65g/cm 3 The hardness was 2400N, the flexural strength was 74MPa, the maximum bending strength was 1:3, the water content was 12%, the rebound rate was 5%, the yield was 87%, and the formaldehyde release level satisfied E1 (see Table 1).
Example 2
A. Wood selection and preliminary processing
The rubber wood is selected as the wood to be processed, and the density of the rubber wood used in the embodiment is 0.60g/cm 3 The hardness is 5300N, the wood is processed into 600mm (length) ×100mm (width) ×30mm (thickness), and the moisture content of the wood is controlled between 20% and 30%。
B. Preparation of curved solid wood
Microwave treatment: placing the wood in kiln type high-power microwave treatment wood equipment for microwave treatment, wherein the frequency of the microwave treatment is 2450MHz, the power of the microwave treatment is 60kW, the time of the microwave treatment is 2min, and the temperature of the microwave treatment is 120 ℃.
Dipping treatment: furfuryl alcohol resin is selected as the adhesive, and the solid content is 50%. The wood is put into a vacuum hydraulic impregnation tank for impregnation treatment, the vacuum degree is controlled to be-0.1 MPa, furfuryl alcohol resin is injected into the vacuum hydraulic impregnation tank, and the pressure in the vacuum hydraulic impregnation tank is increased until the pressure reaches 1.2MPa.
And (3) mould pressing bending: the water content of the impregnated wood is controlled to be 40% by drying in a drying kiln at 60 ℃, and then the impregnated wood is contacted with saturated steam at 120 ℃ for 40min. Then the wood is quickly placed in a mould, and is subjected to cold pressing treatment for 40min under the conditions of 130 ℃ and 15% of compression ratio and 20MPa of pressure, so that the wood is bent into a required shape.
Shaping: placing the curved solid wood with the mould in an oven, drying at 60 ℃ until the water content is 12%, and taking the curved solid wood out of the mould to obtain the curved solid wood with the density of 0.80g/cm 3 The hardness was 5800N, the flexural strength was 96MPa, the maximum bending strength was 1:2, the rebound rate was 8%, the yield was 85%, and the formaldehyde release level satisfied E0 (see Table 1).
Example 3
A. Wood selection and preliminary processing
Selecting poplar (one of the main artificial woods in China with density of 0.353 g/cm) 3 ～0.544g/cm 3 Poor mechanical strength, surface hardness and wear resistance, and poor performance limits the application thereof) is wood to be processed, and the poplar density used in the embodiment is 0.42g/cm 3 The hardness was 1950N, which was processed into a wood of 1500mm (length) ×200mm (width) ×60mm (thickness), and the moisture content of the wood was controlled to be between 40% and 50%.
B. Preparation of curved solid wood
Microwave treatment: the timber is placed in tunnel high-power microwave treatment timber equipment (the length of a microwave cavity is 0.5 m) for microwave treatment, the frequency of the microwave treatment is 433MHz, the power of the microwave treatment is 100kW, the material transmission speed is 1.2m/min (which is equivalent to the time of the microwave treatment being 25 s), and the temperature of the microwave treatment is 135 ℃.
Dipping treatment: the adhesive is maltodextrin adhesive, and the solid content of the adhesive is 40%. Placing wood into a vacuum hydraulic impregnation tank for impregnation treatment, controlling the vacuum degree to be-0.08 MPa, then injecting maltodextrin adhesive into the vacuum hydraulic impregnation tank, and raising the pressure in the vacuum hydraulic impregnation tank until the pressure reaches 1.7MPa.
And (3) mould pressing bending: after the water content of the impregnated wood was controlled to 45% by drying, it was placed in a mold of a hot press preheated to 125℃and heat-pressed for 30 minutes under conditions of a temperature of 125℃and a compression ratio of 40% and a pressure of 20MPa, to bend the wood into a desired shape.
Shaping: and taking the bent solid wood with the die off the hot press and conveying the bent solid wood into a natural air drying room, wherein the drying time is 7 days. Taking out the curved solid wood from the mould to obtain the curved solid wood with the density of 0.75g/cm 3 The hardness was 2600N, the flexural strength was 88MPa, the maximum bending degree was 1:2.5, the water content was 10%, the rebound rate was 10%, the yield was 91%, and the formaldehyde release level satisfied E0 (see Table 1).
Comparative example 1
The reaction conditions were the same as in example 3 except that the power of the microwave treatment was changed from 100kW to 1 kW. The obtained curved solid wood is an unexpanded microwave treated material with a density of 0.49g/cm 3 The hardness was 2050N, the flexural strength was 64MPa, the maximum bending degree was 1:20, the water content was 10%, the rebound rate was 10%, the yield was 20%, and the formaldehyde release rate satisfied E0 (see Table 1).
Comparative example 2
The wood was not "impregnated" and the remaining reaction conditions were the same as in example 3. The resulting curved solid wood was a puffed microwave treated material without gluing, with a yield of 0, and thus was not tested for performance (see table 1).
Comparative example 3
The moisture content of the wood before the microwave treatment was not controlled, the moisture content of the wood itself was 20%, and the other reaction conditions were the same as in example 3. The obtained curved solid wood is an unexpanded microwave treated material with a density of 0.52g/cm 3 The hardness was 2100N, the flexural strength was 68MPa, the maximum bending degree was 1:6, the water content was 10%, the rebound rate was 10%, the yield was 40%, and the formaldehyde release rate satisfied E0 (see Table 1).
Comparative example 4
The moisture content of the wood at the time of press bending was not controlled, and the moisture content of the impregnated wood was 100%, and the other reaction conditions were the same as in example 3. The compression molding bending time is increased, the efficiency is reduced, and the water content is too high, so that the bonding strength is reduced. The density of the obtained bent solid wood is 0.56g/cm 3 The hardness was 2200N, the flexural strength was 70MPa, the maximum bending strength was 1:5, the water content was 20%, the rebound rate was 20%, the yield was 60%, and the formaldehyde release level satisfied E0 (see Table 1).
TABLE 1
Note that: in the above table "/" indicates that the item was not tested.
It should be noted that the above-described embodiments are only for explaining the present invention and do not limit the present invention in any way. The invention has been described with reference to exemplary embodiments, but it is understood that the words which have been used are words of description and illustration, rather than words of limitation. Modifications may be made to the invention as defined in the appended claims, and the invention may be modified without departing from the scope and spirit of the invention. Although the invention is described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, as the invention extends to all other means and applications which perform the same function.
Claims (13)
1. A method of making curved solid wood comprising:
carrying out microwave treatment on wood with the power of 5kW to 300 kW; the temperature of the microwave treatment is 100-180 ℃;
impregnating the wood subjected to microwave treatment through an adhesive; the adhesive is at least one of maltodextrin adhesive, furfuryl alcohol resin and sodium silicate aqueous solution, and the dipping treatment adopts a vacuum pressurizing dipping method, and comprises the step of introducing the adhesive under a vacuum condition;
carrying out mould pressing bending treatment on the impregnated wood; and
shaping the wood subjected to the mould pressing bending treatment to obtain the bent solid wood;
the mould pressing bending treatment comprises the steps of softening the impregnated wood in advance, controlling the water content of the impregnated wood to be 20% -60%, and placing the impregnated wood in a mould press for mould pressing bending treatment; the softening treatment comprises the steps of controlling the water content of the impregnated wood to be lower than 40%, and then enabling the impregnated wood to be contacted with saturated steam at 100-150 ℃ for 20-60 min;
the water content of the wood before the microwave treatment is adjusted according to the wood types, wherein the wood is any one of the radiata pine, the rubber wood and the poplar, and the water content of the radiata pine before the microwave treatment is 60% -70%; the water content of the rubber wood before microwave treatment is 20% -30%; the water content of poplar before microwave treatment is 40-50%.
2. The method according to claim 1, wherein the microwave frequency of the microwave treatment is 100MHz to 5GHz; the microwave treatment time is 10 s-1200 s.
3. The method according to claim 1, wherein the microwave frequency of the microwave treatment is 200MHz to 2450MHz, the time of the microwave treatment is 20s to 600s, and the temperature of the microwave treatment is 100 ℃ to 130 ℃.
4. The method according to claim 1, wherein the microwave frequency of the microwave treatment is 433MHz to 915MHz, and the time of the microwave treatment is 20s to 300s.
5. The preparation method according to claim 1, wherein the solid content of the adhesive is 10% -100%.
6. The preparation method according to claim 1, wherein the solid content of the adhesive is 20% -60%.
7. The preparation method according to claim 1, wherein the solid content of the adhesive is 20% -50%.
8. The production method according to any one of claims 1 to 7, wherein the impregnation treatment is performed under a pressurized condition, wherein the vacuum condition provides a pressure of-0.1 MPa to-0.05 MPa, and the pressurized condition provides a pressure of 0.5MPa to 2.0 MPa.
9. The method according to claim 8, wherein the pressurized condition provides a pressure of 1.0MPa to 2.0 MPa.
10. The method of manufacturing according to claim 1, wherein the press bending processing conditions include: the temperature is 100-150 ℃, the compression ratio is 5-50%, the pressure is 5-30 MPa, and the treatment time is 20-60 min.
11. The method of manufacturing according to claim 1, wherein the press bending processing conditions include: the heating is not carried out, the compression rate is 5-50%, the pressure is 5-30 MPa, and the treatment time is 3-60 min.
12. A curved solid wood prepared according to the preparation method of any one of claims 1 to 11.
13. The curved solid wood of claim 12, wherein said curved solid wood has a moisture content of 8% to 20%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810578794.8A CN108724392B (en) | 2018-06-07 | 2018-06-07 | Preparation method of curved solid wood |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810578794.8A CN108724392B (en) | 2018-06-07 | 2018-06-07 | Preparation method of curved solid wood |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108724392A CN108724392A (en) | 2018-11-02 |
| CN108724392B true CN108724392B (en) | 2024-04-02 |
Family
ID=63932671
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810578794.8A Active CN108724392B (en) | 2018-06-07 | 2018-06-07 | Preparation method of curved solid wood |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108724392B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110421662B (en) * | 2019-07-19 | 2021-04-16 | 山东省惠民县泰森木业有限公司 | Bending method for wooden board |
| CN110405874B (en) * | 2019-08-07 | 2022-06-10 | 来安县扬子地板有限公司 | Method for making artistic floor |
| CN111015878A (en) * | 2019-12-25 | 2020-04-17 | 深圳市山峰智动科技有限公司 | Method, equipment and product for bending single-layer bamboo-wood tableware |
| CN111231040B (en) * | 2020-03-20 | 2022-06-07 | 南京林业大学 | Degradable fiber straw and manufacturing method thereof |
| CN114523536B (en) * | 2022-03-09 | 2023-09-19 | 阜南佳利工艺品股份有限公司 | Treatment process for improving wood processing plasticity |
| CN115464726A (en) * | 2022-09-21 | 2022-12-13 | 索菲亚家居股份有限公司 | Preparation method of powder spraying arc-shaped product and special die |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1498153A (en) * | 2001-03-21 | 2004-05-19 | ��Ī���ѧ | Modified wood product and process for preparation thereof |
| CN105965638A (en) * | 2016-07-11 | 2016-09-28 | 中国林业科学研究院林业新技术研究所 | Microwave treatment reconstructed material and preparing methods thereof |
| CN208359011U (en) * | 2018-06-07 | 2019-01-11 | 中国林业科学研究院木材工业研究所 | A kind of production system of bending of solid wood part |
-
2018
- 2018-06-07 CN CN201810578794.8A patent/CN108724392B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1498153A (en) * | 2001-03-21 | 2004-05-19 | ��Ī���ѧ | Modified wood product and process for preparation thereof |
| CN105965638A (en) * | 2016-07-11 | 2016-09-28 | 中国林业科学研究院林业新技术研究所 | Microwave treatment reconstructed material and preparing methods thereof |
| CN208359011U (en) * | 2018-06-07 | 2019-01-11 | 中国林业科学研究院木材工业研究所 | A kind of production system of bending of solid wood part |
Non-Patent Citations (1)
| Title |
|---|
| 姚文亮.梓木弯曲工艺研究.《硕士电子期刊》.2015,(第第02期期),摘要，第34-37、47-50页. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108724392A (en) | 2018-11-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108724392B (en) | Preparation method of curved solid wood | |
| CN105965638A (en) | Microwave treatment reconstructed material and preparing methods thereof | |
| CN101607411B (en) | Bamboo fiber reinforced composite material and manufacturing method thereof | |
| CN108943208B (en) | A kind of solid wood compression compact sheet production method that Density Distribution is controllable | |
| CN103481348B (en) | Integral reinforced solid wood section bar and manufacturing method thereof | |
| CN109366656B (en) | Control method for density peak shape of single-side compressed wood | |
| WO2011075959A1 (en) | Solid wood section with reinforced surface and preparation method thereof | |
| CN106584634B (en) | A kind of timber surface layer compression method and its timber surface layer staypak | |
| CN102229170A (en) | Method for manufacturing high-quality poplar composite material | |
| CN112077954B (en) | Preparation method of two-dimensional woven green environment-friendly high-strength wood-based composite material | |
| CN105108877A (en) | Scrimber manufacture method | |
| CN102528890B (en) | Manufacturing method for non-adhesive wood fiber part | |
| JP5097604B2 (en) | Wood molding method | |
| CN107498656B (en) | Efficient production method of small-diameter wood composite material | |
| CN106182284A (en) | Microwave treatment material colored garnishing veneer and preparation method thereof | |
| CN108995012A (en) | A kind of preparation method of flame-retardant smoke inhibition bamboo and wood composite laminted wood | |
| CN103722604A (en) | Method for manufacturing bamboo fiber non-glued door plank | |
| WO2014090165A1 (en) | Compressed laminated timber and manufacturing method thereof | |
| CN113103389B (en) | Processing equipment and method for bamboo bending piece | |
| JP5248948B2 (en) | Compressed wood product manufacturing method and compressed wood product | |
| CN110666901B (en) | Environment-friendly moisture-proof wood board and preparation method and application thereof | |
| CN101559616B (en) | Method for forming wood | |
| CN101898374A (en) | Curved plywood and production method | |
| CN102229172A (en) | Method for producing special-shaped bamboo boards | |
| CN113829451B (en) | Process method for expanding, softening and bending wooden flower vehicle hub plate |
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 |