WO2012134353A1

WO2012134353A1 - Method for producing modified wood and device for carrying out said method

Info

Publication number: WO2012134353A1
Application number: PCT/RU2012/000226
Authority: WO
Inventors: Юрий Владимирович БОРИСОВ; Вадим Фаритович ЮСУПОВ; Владислав Геннадьевич БАБИН
Original assignee: Borisov Yurii Vladimirovich; Yusupov Vadim Faritovich; Babin Vladislav Gennadievich
Priority date: 2011-04-01
Filing date: 2012-03-28
Publication date: 2012-10-04
Also published as: RU2466860C1; EP2695710B1; EP2695710A1; RU2011112573A; EP2695710A4

Abstract

The invention relates to the woodworking field and can be used for the production of modified wood of various kinds with simultaneous protective impregnation of said wood. The method for producing modified wood comprises simultaneous drying and impregnation by submerging said wood into an impregnating composition and subjecting the semi-finished product to an acoustic field. The submerging of the semi-finished product into the impregnating composition, the subsequent extraction of said semi-finished product and the at least partial cooling thereof are carried out in an inert gas medium, the molecular weight of which is greater than the molecular weight of oxygen. Before being filled with the inert gas, the volume above the surface of the impregnating composition is pre-evacuated, and the impregnating composition is heated to a temperature of 140-230°С before the semi-finished product is submerged. The device for producing modified wood comprises a drying and impregnating chamber (1) with a cover (2), which chamber is filled with the impregnating composition (3), into which the semi-finished product (4) is placed, and an acoustic energy source (5) which is connected to the drying and impregnating chamber. The drying and impregnating chamber is equipped with a heater (6) which heats the impregnating composition to a temperature of 140-230°С. The cover (2) of the drying and impregnating chamber is hermetically sealed and is provided with at least one connecting pipe (7) which is connected to the evacuation system and to the system for introducing the inert gas. The technical result is that the inventions produce high-quality characteristics in the modified wood.

Description

The method of obtaining modified wood

and device for its implementation

Technical field

The invention relates to the field of woodworking and can be used in the manufacture of modified wood from various species with its simultaneous protective impregnation.

State of the art

A known method of drying wood, comprising immersing wood in a heated liquid medium, placed in a drying and impregnating chamber, and holding it until it reaches a predetermined moisture content of the wood, followed by its cooling (US patent 4366627, 1999). In this case, hot oil is used as a heated liquid medium, and exposure is carried out at a temperature above the boiling point of water.

The disadvantages of the method are the long duration of the process and the uncontrolled depth of impregnation of the treated wood, which for many cases of the use of wood is unacceptable and does not allow to achieve a high conservation effect.

A known method of producing modified wood, including the simultaneous drying, impregnation and pressing of wood in a heated impregnating composition, while the entire process is exposed to the workpiece by an acoustic (ultrasonic) field (RF patent JVb 2391202, IPC V27K 3/08, publ. 10.03.09g .). The application of the method allows to reduce the duration of drying-impregnation of the workpiece and increase the form stability of modified wood: as a result of the action of the acoustic field, compacted wood acquires hydrophobic properties, and its swelling in water does not exceed 12%, which is sufficient for the manufacture of sleepers. This method is the closest to the claimed technical solution and is selected for the prototype.

However, using this method, it is not possible to obtain high-quality wood for artwork, because the processed wood acquires an uneven coloring over the cross section, and there is no possibility of controlling the color of the wood.

A device for drying wood that implements a method of drying wood (patent US 4366627, 1999). The device includes a drying and impregnation chamber filled with a heated liquid medium in which the preform is placed. The billet is kept in a drying and impregnation chamber until the specified moisture content of the wood is reached, and then cooled. In this case, hot oil is used as a heated liquid medium, and exposure is carried out at a temperature above the boiling point of water. The device provides drying of the wood billet and impregnation of the surface layer with oil. The disadvantages of the device are the long duration of the process and the uncontrolled depth of impregnation of the processed wood, which for many cases of using wood is unacceptable and does not allow to achieve a high conservation effect.

A device for producing modified wood is known that implements a method for producing modified wood (RF patent j 2391202 IPC B27K 3/08, publ. 10.03.09). The device comprises a drying and impregnating chamber with a lid filled with an impregnating composition in which the workpiece is placed, and a source of acoustic energy connected to the drying and impregnating chamber. The device provides simultaneous drying, impregnation and pressing of the wood of the workpiece in a heated impregnating composition under the influence of an acoustic (ultrasonic) field.

The device allows to reduce the duration of drying-impregnation of the workpiece and increase the form stability of modified wood: as a result of the action of the acoustic field, compacted wood acquires hydrophobic properties, and its swelling in water does not exceed 12%, which is sufficient for the manufacture of sleepers. This device is the closest to the claimed technical solution and is selected as a prototype.

However, this device does not allow to obtain high-quality wood for artwork, because wood acquires a color uneven in cross section, and there is no possibility to control the tone (color) of wood.

Disclosure of invention

The objective of the invention is to develop a method and device for its implementation, which can improve the quality characteristics of modified wood.

The problem is solved using the signs specified in

1-m claim common to the prototype such as a method for producing modified wood, including simultaneous drying, impregnation by immersion in an impregnating composition and exposure of the workpiece to an acoustic field, and distinctive. Essential features, such as immersion of a workpiece in an impregnating composition, its subsequent extraction and at least partial cooling, are carried out in an inert gas medium whose molecular weight is greater than the molecular weight of oxygen, while before filling with an inert gas, the volume above the surface of the impregnating composition is pre-evacuated and the impregnating composition before immersion of the workpiece is heated to a temperature of 140-230 ° C.

Paragraphs 2 and 3 of the claims reflect the features of the placement of the workpiece, namely, the process is carried out with vertical wood fiber position of the workpiece; the preform is partially immersed in the impregnating composition, while the upper part, the end face of the preform is left above the surface of the impregnating composition.

According to paragraph 4. the claims use wax-like substances as an impregnating composition.

Immersion of the workpiece in the impregnating composition, its subsequent extraction and, at least partially, cooling in an inert gas medium, the molecular weight of which is greater than the molecular weight of oxygen, with preliminary evacuation of the volume above the surface of the impregnating composition, can reliably exclude contact with oxygen as an impregnating air composition and preform at all stages of the process, which eliminates the oxidation of pre-heated wood and impregnating composition, carbonization and lower quality of the finished material.

Heating the impregnating composition before immersing the workpiece to a temperature of 140-230 ° C allows simultaneously with the processes of drying, impregnation and compaction of wood to carry out its thermal modification (coloring the wood in natural tones without the use of chemical dyes), the condition for which for wood of various species is the thermal effect in the specified temperature range with limited access to oxygen. The degree of thermal modification and, accordingly, the color of the wood (from light tones to shades of black) is set by adjusting the temperature within the specified range and the duration of the treatment.

The implementation of the method at the vertical position of the workpiece along the wood fiber allows the same conditions of impregnation along the workpiece cross section due to the uniform flow of convection and diffusion processes as a result of the correspondence of the direction of the location of the wood fibers to the direction of gravity forces, which ensures the best quality of wood impregnation.

Partial immersion of the workpiece in the impregnating composition, leaving the upper part (end) of the workpiece above the surface of the impregnating composition, allows to facilitate the release of moisture vapor from the wood of the workpiece through this end, the surface of which is not covered by the impregnating composition, which allows for more uniform humidity and high quality of the finished material according to the entire volume.

The use of wax-like substances as an impregnating composition allows, due to their fluidity property in the capillary structure of wood under the action of an acoustic field, to ensure uniform impregnation, high quality and high environmental characteristics of the finished material. At the same time, wax-impregnated wood allows surface treatment to a high degree of purity.

The above set of essential features provide high quality characteristics of modified wood.

Obtained using this method, high-quality modified wood made from coniferous and deciduous species, having through volumetric impregnation, different density and color, is given the name "wood".

The problem is solved using the characteristics specified in paragraph 5 of the claims common with the prototype, such as a device for producing modified wood, including a drying and impregnating chamber with a lid filled with an impregnating composition in which the workpiece is placed, and a source connected to the drying and impregnating chamber acoustic energy, and distinctive, essential features such as a drying and impregnating chamber is equipped with a heater that provides heating of the impregnating composition to a temperature of 140-230 ° C, and cr The tower of the drying and impregnation chamber is sealed and provided with at least one nozzle connected to an inert gas evacuation and gas filling system.

According to claim 6, the drying and impregnation chamber is configured to place the preform in it vertically according to the largest size of the preform, and the acoustic energy source is connected to the drying and impregnating chamber from the bottom.

A particular embodiment of the lid of the drying and impregnating chamber is reflected in claim 7, namely, the lid of the drying and impregnating chamber is made in the form of a hollow chamber, at least equal in volume to the drying and impregnating chamber.

According to claim 8, the device is equipped with a mechanism (10) for controlled loading of the workpiece into the drying and impregnation chamber and its extraction.

The presence of a heater of the drying and impregnating chamber, which ensures heating of the impregnating composition to a temperature of 140-230 ° C, allows you to maintain and control the temperature of the impregnating composition, which allows you to provide the specified depth of thermal modification of the wood of the workpiece and give it the desired color cast.

Making the cover of the drying and impregnating chamber airtight allows hermetically limiting the volume above the surface of the impregnating composition in the drying and impregnating chamber, and supplying the cover with at least one nozzle connected to inert gas evacuation and gas filling systems allows air to be removed and the volume filled with an inert gas for prevent contact with air and oxidation of the heated impregnating composition and the workpiece.

The implementation of the drying and impregnation chamber with the possibility of placing the workpiece vertically to the largest size / workpiece in it and, at the same time, the connection of the acoustic energy source with the drying and impregnation chamber from the side of its lower end allows the same conditions for impregnation over the cross section of the workpiece due to the uniform flow of convection and diffusion processes in the impregnating composition as a result of the correspondence of the direction of arrangement of wood fibers to the direction of action of acoustic energy, as well as the direction of action of gravitational forces, which ensures the best quality of wood impregnation.

The execution of the cover of the drying and impregnating chamber in the form of a hollow chamber, at least equal in volume to the drying and impregnating chamber, allows you to place a workpiece under the cover in an inert gas medium before immersion and upon completion of the process, excluding contact of the workpiece with oxygen, carbonization and lower quality of the finished product material.

Providing the device with a mechanism for controlled loading of the workpiece into the drying and impregnation chamber and its extraction allows

to partially and completely immerse the workpiece for a given time, ensuring the execution of manufacturing modes

modified wood, achieving high quality characteristics.

The invention is illustrated by examples of implementation and drawing Example. The method is as follows.

Prepare billets from wood of various species, usually with a moisture content of 20-60%. Billets are placed in a volume above the drying and impregnation chamber, which is pre-vacuum and filled with an inert gas with a molecular weight greater than that of oxygen (for example, argon). The drying and impregnating chamber is filled with an impregnating composition, which is heated to a temperature from 140 to 230 ° C, depending on the required degree of wood modification and the selected impregnation mode. The preforms are immersed, partially or in whole, preferably located in the vertical direction along the fiber, in the impregnating composition and held there, in one or several stages, for a given modification time. Acoustic energy is brought to the drying and impregnation chamber and the modification process is carried out. Vaporized wood moisture is removed from the volume above the drying and impregnation chamber. At the end of the process, the preforms are removed from the impregnating composition and cooled in an inert gas medium to a temperature of no higher than 140 ° C, after which they are stored in air as a finished “wood” material.

In this case, an inert gas in the volume above the drying and impregnation chamber reliably excludes contact with oxygen of the air, both of the impregnating composition and the workpieces at all stages of the process, which eliminates the oxidation of heated wood and impregnating composition, carbonization and a decrease in the quality of the finished material. In the impregnating composition at a temperature of 140-230 ° C, simultaneously with the processes of drying, impregnation and compaction of wood, its thermal modification occurs. Vertical immersion of the workpieces along the fiber of the wood, partial or phased immersion of the workpieces in the impregnating composition provide a more uniform removal of moisture and impregnation of the workpieces. Impregnation of preforms with wax-like substances ensures high environmental characteristics of the finished material.

Modified wood “wood” made from various conifers and deciduous species has a uniform impregnation in volume, coloring from light tones to shades of black (without the use of chemical dyes), the absence of cracks and internal stresses, high form stability, which is a high quality indicator.

The density of modified wood “woods” increases up to two times, the hardness of conifers increases to 150%, deciduous - up to 127%.

For example, the modified wood “wood” obtained by the proposed method, made of birch (impregnation is beeswax, modification temperature 220-230 ° C) has a black-brown color, density up to 1.2 kg / m ³ and hardness up to 45 n / m , in appearance it corresponds to black bog oak, being an analogue of expensive valuable species of wood.

The exact landing dimensions of parts made of “wood” wood remain within tolerances with fluctuations in ambient humidity from 12 to 100%.

The manufacturing time for modified wood “shakes” from hardwood for blanks with a thickness of 50-100 mm is from 10 minutes at a temperature of 140 ° C (the color of the paint is close to the original), up to 1, 5 hours at a temperature of 220-230 ° C for coloring "black oak".

The implementation of the proposed method using the device is illustrated in the drawing, FIG.

A device for implementing the method of producing modified wood "wood" contains drying the impregnation chamber 1 with a cover 2, filled with an impregnating composition 3, into which the workpiece 4 is placed. and an acoustic energy source 5 connected to the drying and impregnating chamber 1. The drying and impregnating chamber 1 is equipped with a heater 6, providing heating of the impregnating composition 3 to a temperature of 140- 230 ° C, and the cover 2 of the drying and impregnation chamber 1 is sealed and provided with at least one pipe 7 connected to inert gas evacuation and gas filling systems (not shown). The blank 4 is located in the drying and impregnation chamber 1 vertically with the largest size /, and the acoustic energy source 5 is connected to the drying and impregnating chamber 1 from the bottom end 8. The cover 2 of the drying and impregnating chamber 1 is made in the form of a hollow chamber 9. Under the cover 2, it is drying - impregnation chamber 1 is a mechanism 10 for the adjustable loading and extraction of the workpiece 4.

The device operates as follows.

The drying and impregnating chamber 1 is loaded with an impregnating composition 3, hermetically sealed with a lid 2, in the cavity 9 of which a blank 4 is fixed on the mechanism 10. The cavity 9 of the lid 2 is evacuated through the nozzle 7 and filled with an inert gas (argon). The impregnating composition 3 using a heater 6 is heated to a temperature in the range from 140 to 230 ° C. The workpiece 4 using the mechanism 10 is immersed in the impregnating composition 3 and maintained in accordance with a given process mode. The acoustic energy from the source of acoustic energy (emitter) 5 is supplied from the bottom end 8 of the drying and impregnation chamber 1 to the impregnating composition 3 and the process is carried out. At the end of the process, the preform 4 is removed using the mechanism 10 from the impregnating composition 3, placed in the volume 9 of the cover 2 and the cooling of the preform 4 in an inert gas medium to a temperature of no higher than 140 ° C (the position of the preform 4 in the volume 9 is shown by a dotted line). After cooling the workpiece 4, argon from volume 9 through the nozzle 7 is removed, the lid 2 is separated from the drying and impregnation chamber 1, from the volume 9 of the lid 2 using the mechanism 10, the finished material is extracted - the modified wood "wood".

Modified wood “wood” made with the help of the invention has uniform through-through impregnation in volume, coloring from light tones to shades of black (without the use of chemical dyes), density up to 1.2 kg / m ³ , no cracks and internal stresses, high form stability , which are high quality indicators. Industrial applicability

The present invention can be made of available materials and components on serial equipment in an industrial environment. It will find wide application in the field of woodworking, in construction, furniture production, in decorative processing of wood and artwork.

Although the present invention is described through examples of its implementation and the drawing, the scope of this invention is not limited to these examples, but is determined only by the claims taking into account possible equivalents.

Claims

Claim

1. The method of obtaining modified wood, including simultaneous drying, impregnation by immersion in the impregnating composition and exposure to the workpiece with an acoustic field, characterized in that the workpiece is immersed in the impregnating composition, its subsequent extraction and, at least partially, cooling is carried out in an environment inert gas, the molecular weight of which is greater than the molecular weight of oxygen, while before filling with an inert gas, the volume above the surface of the impregnating composition is pre-evacuated, and the impregnation yuschy composition before immersing the preform is heated to a temperature of 140-230 ° C.

2. The method according to claim 1, characterized in that the process is carried out with the position of the workpiece vertical along the wood fiber.

3. The method according to claim 1, characterized in that the preform is partially immersed in the impregnating composition, while the upper part, the end face of the preform is left above the surface of the impregnating composition.

4. The method according to claim 1, characterized in that wax-like substances are used as the impregnating composition.

5. A device for producing modified wood, including a drying and impregnating chamber with a lid, filled with an impregnating composition in which the workpiece is placed, and a source of acoustic energy connected to the drying and impregnating chamber, characterized in that the drying and impregnating chamber is equipped with a heater for heating the impregnating composition to a temperature of 140-230 ° C, and the lid of the drying and impregnating chamber is sealed and provided with at least one nozzle connected to vacuum systems and azonapolneniya inert gas.

6. The device according to claim 5, characterized in that the drying and impregnation chamber is arranged to place the workpiece vertically in the largest size of the workpiece, and the acoustic energy source is connected to the drying and impregnation chamber from the bottom.

7. The device according to claim 5, characterized in that the cover of the drying and impregnating chamber is made in the form of a hollow chamber, at least equal in volume to the drying and impregnating chamber.

8. The device according to claim 5, characterized in that it is equipped with a mechanism for the controlled loading of the workpiece into the drying and impregnation chamber and its extraction.