阅读说明：本技术 一种木材密实化的方法及密实化设备 (Wood densification method and densification equipment ) 是由 钟世禄 蒋明月 张钰 于 2021-07-28 设计创作，主要内容包括：一种木材密实化的方法及密实化设备,将木材置于设备中,注入乙醇浸没木材,加热至温度T1,浸没后,排出溶液；再加热并同步抽真空至温度T2后恒定,再依次经热处理、饱和汽蒸处理、于浸渍剂中辊压木材后,干燥,完成木材密实化。其以充分改善渗透通道为前提,在真空下以一定的温度,将热干、汽蒸、辊压和浸渍相结合,使得经历各密实步骤的木材保持性能的稳定,提高各密实步骤的效率和一体衔接性；再通过在同一密闭腔内完成不同的密实步骤,提高操作步骤的连续性。将纳米Ti/TiO-2引入木材内层及表层,增强并改善木材的密实、抗磨、抗压等机械性能。其结构简单,步骤清晰连贯,木材的密实效果好,强度高,具有很强的实用性和广泛的适用性。(A method for densifying wood and its equipment are disclosed, which includes immersing wood in alcohol, heating to T1, immersing,discharging the solution; then heating and synchronously vacuumizing to a constant temperature T2, then sequentially carrying out heat treatment, saturated steaming treatment, rolling wood in impregnant, and drying to finish the densification of the wood. On the premise of fully improving a permeation channel, hot drying, steaming, rolling and dipping are combined at a certain temperature under vacuum, so that the wood subjected to each compaction step is stable in performance, and the efficiency and the integral connectivity of each compaction step are improved; and then different compacting steps are completed in the same closed cavity, so that the continuity of the operation steps is improved. Mixing nano Ti/TiO 2 The inner layer and the surface layer of the wood are introduced to enhance and improve the mechanical properties of the wood, such as compactness, wear resistance, compression resistance and the like. The wood compacting machine is simple in structure, clear and coherent in steps, good in wood compacting effect, high in strength, strong in practicability and wide in applicability.)

1. A method for densifying wood, comprising the steps of: the wood is put into a closed vessel,

s1, injecting ethanol into the container to immerse the wood, heating to the temperature of T1, and discharging the solution after immersing for a period of time;

s2, heating and synchronously vacuumizing to a temperature T2, wherein the temperature is constant:

s21, heat-treating the wood for a period of time;

s22, discharging steam after the wood is treated by saturated steam;

s23, injecting a impregnant into the container, and impregnating for a period of time after rolling the wood in the impregnant;

and S3, taking out the impregnated wood, and drying to finish the densification of the wood.

2. A method for densifying wood according to claim 1, wherein the ethanol immersion time in step S1 is 3-7 days, and the temperature T1 is 50-60 ℃.

3. The method according to claim 1, wherein the temperature T2 in the step S2 is 130-150 ℃, the heating mode is a gradient of 5 ℃/10min, and the vacuum is extracted along with the temperature gradient; the heat treatment time is 20-30 h.

4. The method for densifying wood according to claim 1, wherein the steaming temperature in step S22 is 130-150 ℃.

5. A method for densifying wood according to claim 1, characterized in that the impregnant comprises nano Ti/TiO containing₂The phenolic resin has a solid content of 33-70%, a pH value of 6.9-8.7 and Ti/TiO₂The mass content of the composite is 0.01-1%, and the dipping time after rolling is 1-2 h.

6. A method for densifying wood according to claim 1, wherein the drying in step S3 is 150 ℃ for 36-48 h.

7. A wood densification plant adapted for use in a method of wood densification according to any of claims 1-6, comprising a hollow box and a matching box lid;

along vertically, establish a plurality of groups of roll-in channels in the box: comprises a press roller group and a plurality of limit roller groups; the pressing roller sets are vertically arranged at the cavity bottom of the box body along the longitudinal center line of the box body through the roller shafts, and the plurality of limiting roller sets are symmetrically arranged on two sides of each pressing roller set; the diameter of the compression roller is larger than that of the limiting roller;

along the longitudinal direction, the pushing plate is vertical to any end of the bottom surface of the box body, which is arranged on the roller pressing channel, is in threaded connection with a screw rod transversely arranged in the box body, and two side surfaces of the pushing plate slide along sliding grooves arranged on the side walls of the box body; the screw is driven by a motor outside the box body;

the box body is provided with a plurality of injection ports with valves and a vacuumizing port, and the liquid outlet with the valves is arranged at the bottom of the box body; the heating assembly is arranged in the side wall or the bottom wall and is driven by the control device.

8. A wood compacting apparatus according to claim 7, wherein the set of limiting rollers includes a lower set of limiting rollers and an upper set of limiting rollers,

the lower limiting roller set is vertically arranged at the bottom of the cavity of the box body through a roller shaft, and the upper limiting roller set is arranged at the bottom surface of the box cover and corresponds to the lower limiting roller set.

9. The wood densification facility of claim 7, wherein the vacuum-pumping port is disposed on a top surface of the box cover and is communicated with a plurality of air outlets disposed on a bottom surface of the box cover through air passages.

10. A wood compacting device according to claim 7, wherein a liquid level sensor and a temperature sensor are arranged in the box body and are respectively connected with the control device.

Technical Field

The invention relates to a process for wood densification, in particular to a method and equipment for wood densification.

Background

The wood is the only renewable structural material in four major building materials (cement, steel, plastic and wood) in the world at present, and is widely applied to the industries of building, furniture manufacturing, pulping, paper making and the like. Compared with steel and alloy materials, the wood has the advantages of light weight, less environmental damage, environmental protection, cyclic utilization and the like; compared with some polymers and bionic composite materials, the preparation method has the advantages of simple manufacturing process, low cost and the like. In recent years, as some non-renewable natural resources (petroleum, metal, etc.) are increasingly reduced, the advantages of wood materials as renewable resources are becoming more and more obvious.

China is a country with extremely scarce wood resources, and because the demand of people for wood is increasing day by day, the contradiction between supply and demand of wood in China is further aggravated. In order to alleviate the contradiction, at present, the wood industry of China is in the strategic transition process from using natural forest wood as a main material to using fast-growing artificial forest wood as a main material, and the fast-growing artificial forest wood is the main wood raw material of China in future. In order to overcome the defects of loose wood material, easy cracking and deformation, low density, decay resistance and short service life of the fast-growing artificial forest, the fast-growing wood is usually strengthened by adopting impregnation treatment and compression densification treatment, and particularly the performance of the fast-growing wood can be greatly improved by the compression densification treatment, so that the utilization rate is improved.

In the existing reports, the fast growing wood is usually pretreated by methods such as hydrothermal softening, microwave softening, resin impregnation and the like before compression and densification, but the compression rate is not high, the dimensional stability is not high, and the deformation and recovery are very easy.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide a method for compacting wood and a compacting device.

In order to achieve the above object, the present invention adopts the following technical solutions:

a method of wood densification comprising the steps of: the wood is put into a closed vessel,

s1, injecting ethanol into the container to immerse the wood, heating to the temperature of T1, and discharging the solution after immersing for a period of time;

s2, heating and synchronously vacuumizing to a temperature T2, wherein the temperature is constant:

s21, heat-treating the wood for a period of time;

s22, discharging steam after the wood is treated by saturated steam;

s23, injecting a impregnant into the container, and impregnating for a period of time after rolling the wood in the impregnant;

and S3, taking out the impregnated wood, and drying to finish the densification of the wood.

The ethanol immersion time in the step S1 is 3-7 days, and the temperature T1 is 50-60 ℃.

The temperature T2 in the step S2 is 130-150 ℃, the heating mode is a gradient type of 5 ℃/10min, and the vacuum is extracted along with the temperature gradient; the heat treatment time is 20-30 h.

The steaming temperature in the above step S22 is 130-150 ℃.

The impregnant comprises nano Ti/TiO₂The phenolic resin has a solid content of 33-70%, a pH value of 6.9-8.7 and Ti/TiO₂The mass content of the composite is 0.01-1%, and the dipping time after rolling is 1-2 h.

The drying in the step S3 is carried out at 150 ℃ for 36-48 h.

A wood densification device comprises a hollow box body and a matched box cover;

along vertically, establish a plurality of groups of roll-in channels in the box: comprises a press roller group and a plurality of limit roller groups; the pressing roller sets are vertically arranged at the cavity bottom of the box body along the longitudinal center line of the box body through the roller shafts, and the plurality of limiting roller sets are symmetrically arranged on two sides of each pressing roller set; the diameter of the compression roller is larger than that of the limiting roller;

along the longitudinal direction, the pushing plate is vertical to any end of the bottom surface of the box body, which is arranged on the roller pressing channel, is in threaded connection with a screw rod transversely arranged in the box body, and two side surfaces of the pushing plate slide along sliding grooves arranged on the side walls of the box body; the screw is driven by a motor outside the box body;

the box body is provided with a plurality of injection ports with valves and a vacuumizing port, and the liquid outlet with the valves is arranged at the bottom of the box body; the heating assembly is arranged in the side wall or the bottom wall and is driven by the control device.

The limiting roller set comprises a lower limiting roller set and an upper limiting roller set,

the lower limiting roller set is vertically arranged at the bottom of the cavity of the box body through a roller shaft, and the upper limiting roller set is arranged at the bottom surface of the box cover and corresponds to the lower limiting roller set.

The vacuumizing port is arranged on the top surface of the box cover and is communicated with a plurality of air outlets arranged on the bottom surface of the box cover through air passages.

A liquid level sensor and a temperature sensor are arranged in the box body and are respectively connected with a control device.

The invention has the advantages that:

according to the method and the equipment for wood densification, provided by the invention, on the premise of fully improving a permeation channel, hot drying, steaming, rolling and impregnation are combined at a certain temperature under vacuum, so that the wood subjected to each densification step keeps stable in performance, and the efficiency and the integral connectivity of each densification step are improved; and different compacting steps are completed in the same closed cavity, so that the continuity of the operation steps is improved, the former step is prepared for the next step, and the effect of the next step is improved. By containing nano Ti/TiO₂Filling the permeation channel with the impregnant, and adding nano Ti/TiO₂The inner layer and the surface layer of the wood are introduced, so that the mechanical properties of the wood, such as compactness, wear resistance, compression resistance and the like, are enhanced and improved.

The method and the equipment for densifying the wood have the advantages of simple structure, clear and coherent steps, capability of realizing automatic densifying operation of the wood by combining the control device, good densifying effect of the wood, high strength, strong practicability and wide applicability.

Drawings

Fig. 1 is a schematic view of the structure of a roller tunnel.

FIG. 2 is a schematic structural view of section A-A.

Fig. 3 is a schematic structural view of the vacuum-pumping port.

The designations in the drawings have the following meanings: 1. the device comprises a compression roller set, 2, a limiting roller set, 3, a screw, 4, a pushing plate, 5, a heating assembly, 6, an upper limiting roller set, 7, a lower limiting roller set, 8, a sliding groove, 9, a liquid level sensor, 10, a temperature sensor, 11, a first injection opening, 12, a second injection opening, 13, a liquid discharge opening, 14, an air outlet, 15 and a vacuumizing opening.

Detailed Description

The invention is described in detail below with reference to the figures and the embodiments.

A wood compacting device consists of a hollow box body and a box cover.

The box is internally provided with a plurality of groups of driven rollers vertically, a dry group roller channel is formed in the box along the longitudinal direction, the roller channel is composed of a group of compression rollers and a plurality of groups of limiting roller groups 2, the diameter of each compression roller is larger than that of each limiting roller, the compression rollers are vertically arranged at the bottom of the cavity of the box along the longitudinal central line of the box through compression roller shafts, and the compression roller shafts are arranged in shaft grooves in the bottom surface of the box cover and are limited by the shaft grooves. The limiting roller sets 2 are symmetrically arranged on two sides of the pressing roller set 1 along the central line, each limiting roller set 2 is composed of a corresponding lower limiting roller set 7 and an upper limiting roller set 6, the lower limiting roller sets 7 are vertically arranged at the bottom of the cavity of the box body through the roller shafts, and the upper limiting roller sets 6 are vertically arranged on the bottom surface of the box cover through the roller shafts. And a gap is reserved between the lower limiting roller set 7 and the upper limiting roller set 6 and used for passing through the pushing plate 4.

Along the longitudinal direction, the pushing plate 4 is arranged at any end of the roller channel, is vertical to the bottom surface of the box body and is in threaded connection with the screw rods 3 transversely arranged in the box body; the screw rod 3 is linked by a control device through a motor shaft outside the box body; the both ends of bulldozing board 4 paste the inside wall of box to along locating the horizontal spout 8 slip on the inside wall.

The heating assembly 5 is arranged in the side wall or the bottom wall, the liquid outlet 13 with a valve is arranged at the bottom of the box body, and the liquid level sensor 9 and the temperature sensor 10 are arranged in the box body; preferably, the box cover is provided with a plurality of first injection ports 11 with valves, a plurality of second injection ports 12 and a plurality of vacuum ports 15, and the vacuum ports 15 arranged on the top surface of the box cover are communicated with a plurality of air outlets 14 arranged on the bottom surface of the box cover through air passages. The heating component 5, the liquid level sensor 9, the temperature sensor 10, the valves of the first injection port 11 and the second injection port 12, and the vacuum pump connected with the vacuumizing port 15 are respectively connected with a control device and driven by the control device.

Preferably, the end surface of the pushing plate 4 facing the formwork can be provided with an arc shape, a conical shape or the like, so that the pushing plate 4 pushes the wood board out of the press rolls in a whole without being blocked by the press rolls, and the tail end of the wood board is clamped between the press rolls.

A method for densifying wood comprises the following steps: placing the wood in a roller channel in a box body of densification equipment, wherein two side surfaces of the wood are respectively abutted against a limiting roller, one end of the wood is abutted against a pressing roller, and the other end of the wood is abutted against a pushing plate 4; sealing the box cover by a solid cover;

s1, injecting ethanol into the box body through the first injection port 11, stopping injecting the ethanol after the injected ethanol is immersed in the wood through the feedback of the liquid level sensor 9, and closing a valve of the first injection port 11; the control device drives the heating component 5 to heat to 50-60 ℃, the temperature is maintained to be immersed for 3-7 days, and the solution is discharged through the liquid outlet 13;

the wood is pretreated by ethanol, oil on the surface of the wood is dissolved, water in raw wood is replaced, extracts in part of the wood are dissolved, and the permeability of the wood is improved by improving a permeation channel. At a certain temperature, the fiber cells in the wood are in an active state, the inner wall and the cell membranes of the cells are activated, the replacement and dissolution efficiency is improved, and preheating is carried out for the following steps.

S2, driving the heating component 5 to heat the temperature in the box body by the control device, maintaining the gradient type after 5 ℃ per liter in the heating mode for 10min, and pumping vacuum to a certain degree in a maintaining time period until the temperature in the box body reaches 130-150 ℃, and simultaneously, the vacuum degree reaches-0.1 MPa to-0.09 MPa, and under the condition of maintaining the temperature and the vacuum degree, further performing the following steps:

the inner layer and the outer layer of the preheated wood have uniform temperature, and ethanol and water in the permeation channel of the wood are dried in a mode of heating in a gradient manner, so that the moisture content of the wood is reduced, and the effect of dredging the permeation channel is achieved. The uniformly distributed air outlets 14 can improve the efficiency and effect of extracting the steam and the ethanol evaporated in the box body during vacuum pumping, prevent the steam and the ethanol from accumulating in the box body, and reduce the effect of heat treatment, such as increasing the interfacial tension in a permeation channel.

S21, performing heat treatment for 20-30 h; through the continuous high temperature under low pressure, the water vapor in the wood presses the walls of the wood cells, so that new channels are formed, and permeation channels are further increased and improved; meanwhile, the interfacial tension in the permeation channel due to water evaporation is reduced through continuous heat treatment for a certain time, so that the condition of local channel closure is caused, preparation is made for next steaming, and the steaming effect is improved.

S22, after fumigating the wood by saturated steam at the temperature of 130-150 ℃, discharging the steam; after the steam is discharged, vacuumizing and stabilizing to-0.1 MPa to-0.09 MPa, or vacuumizing to extract the steam;

the wood dried at high temperature is subjected to high-temperature steam to soften the surface layer of the wood, and the permeation channel and the parenchyma are damaged to a certain extent, so that the permeability of the wood is further improved.

S23, injecting a impregnant into the vessel through the second injection port 12, driving the screw rod 3 to rotate through the motor by the control device after wood is immersed, linking the pushing plate 4 to slide along the sliding groove 8, further pushing the wood into the press roller group 1, realizing rolling the wood in the impregnant, and impregnating for 1-2 hours after rolling.

The impregnated impregnant enters the wood through the penetration channel and is rolled, the surface layer of the wood is compacted, and the impregnant penetrating into the surface layer is pressed into the inner layer; after the compacted surface layer leaves the press roller, the elastic reset deformation of a certain degree forms negative pressure in the wood, and further the impregnant is absorbed into the surface layer of the wood to form an inner and outer double-layer compact layer.

Nano Ti/TiO in impregnant₂The particles are uniformly distributed in the wood through the permeation channels, so that the strength, rigidity and wear resistance of the compact layer are further enhanced. The phenolic resin also improves the corrosion resistance, acid resistance, insulation, heat resistance and other properties of the wood. A certain amount of ethanol can also be added into the impregnant,is a penetration assisting agent; can be evaporated off in a subsequent drying step.

S3, taking out the impregnated compressed and densified wood, placing the wood in an oven, preserving the heat for 36-48h at the temperature of 150 ℃, and performing heat fixation to obtain the densified wood.

The impregnant is prepared from Ti/TiO nanoparticles₂The phenolic resin has the solid content of 33-70 percent, the pH value of 6.9-8.7 and the mass content of Ti/TiO2 of 0.01-1 percent. Ti/TiO2₂Preferably less than 100 nm.

In practical use, each parameter in the embodiment can be adjusted according to the use requirement, so as to achieve the matched use effect.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It should be understood by those skilled in the art that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by using equivalent alternatives or equivalent variations fall within the scope of the present invention.