KR20180127864A - Method for manufacturing compressed wood having improved dimensional stability - Google Patents

Abstract

The present invention relates to a method for manufacturing compressed wood, which can prevent a spring back phenomenon caused by moisture absorption of thermally compressed wood.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for manufacturing compressed wood,

The present invention relates to a method for manufacturing compressed wood which can prevent the springback phenomenon due to moisture absorption of a thermally compressed wood.

The heat treatment of wood is carried out by heating at high temperature to control the thermal decomposition of the wood component while inducing the change of the chemical component to increase the dimensional stability and weatherability and to reduce the hygroscopicity. This heat treated wood can be applied to a variety of applications requiring dimensional stability and weatherability, such as garden furniture, fences, pillars, wooden cabinets, window frames, doors, furniture, decking materials, However, due to the thermal decomposition of some wood components due to high heat during the heat treatment process, the inherent density of the wood decreases, the modulus of elasticity (MOE) and the modulus of rupture (MOR) decrease, the impact strength decreases, , Darkening color, odor, and increased metal corrosion (Sandberg & Kutnar, 2015; Guo et al., 2014). In this regard, Stamm et al. (1946) first reported systematic heat treatment for improving the weatherability of wood, and so far, continuous research has been conducted to solve the problems caused by heat treatment and the efficiency of the process.

In addition, researches have been conducted on changes and improvements of other physical properties such as paintability, surface processability, adhesiveness, and metal corrosion resistance by heat treatment. For example, the weathering resistance of heat-treated wood is similar to that of untreated wood, so it has been reported that surface treatment such as painting is required for outdoor use (Mayes & Oksanen, 2002) (Yildiz, et al., 2010). However, it has been reported that MOR is reduced to 50% of the untreated material. Petric et al. (2007) used various surface paints to improve the weathering resistance of heat-treated wood. As a result, outdoors heat-treated timber was more resistant to fading compared to untreated wood, and opaque paint was more resistant to surface deterioration And the effect was significant. In addition, when the heat-treated wood is subjected to the adhesive treatment, the shear strength is lowered due to the heat treatment, the wood quality is damaged due to the damage of the wood, and the penetration of the solvent into the adhesive is delayed due to the increase in hydrophobicity due to the heat treatment. (Sandberg and Kutnar, 2015; Mayes and Oksanen, 2002; Rapp et al., 2000). In addition, although the heat treatment itself may lead to deterioration of the component of the wood to stabilize the dimension due to disappearance of the hydrophilic group, in general, the thermally compressed wood is restored to its dimension while absorbing moisture over time (springback phenomenon) The fact that it is unstable to use for outside air is also one of the problems to be overcome.

1. Boonstra, M. J., Tjeerdsma, B. F., Groeneveld, H.A.C. 1998. Thermal modification of non-durable wood species. 1. The PLATO technology: thermal modification of wood. The International Research Group on Wood Protection, Document no. IRG / WP 98-40123. 2. Sandberg, D., Kutnar, A. 2015. Recent Development of Thermal Wood Treatments: Relationship between Modification Processing, Product Properties, and the Associated Environmental Impacts, IAWPS 2015, International Symposium on Wood Science and Technology, p. 55-59. 3. Tjeerdsma, B. F., Boonstra, M., Militz, H. 1998b. Thermal modification of non-durable wood species. 2. Improved wood properties of thermally treated wood. International Research Group on Wood Preservation, Document no. IRG / WP 98-40124. 4. Guo F., Huang, R., Lu, J., Chen, Z., Cao, Y. 2014. Evaluating the effect of heat treating temperature and duration on selected wood properties, J. Wood Sci. 60: 255-262. 5. Kamdem, D. P., Pizzi, A., Guyonnet, G., Jermannaud, A. 1999. Durability of heat-treated wood, The International Research Group on Wood Protection, IRG / WP 99-40145. 6. Won, K. R., Hong, N. Y., Kwon, S. S., Jeong, S. H., Byun, H. S. 2015. Application of heat-treated wood with heat medium, 2015. Proceedings of the Korean Society of Wood Science and Technology Annual Meeting, 344-345. 7. Hong, N.Y., Kwon, S.S., Jeong, S.H., Won, K.R., Byun, H.S. 2014. Decay of heat-treated wood by concentration of heat medium, 2014. Proceedings of the Korean Society of Wood Science and Technology Annual meeting: 320-321. 8. Ra, J. B., Kim, K. B., Lim, K.H. 2012. Effect of heat treatment conditions on color change and termite resistance of heat-treated wood, J. Korean Wood Sci. & Tech. 40 (6): 370-377. 9. Lee, S.J., Kang, S.K., Kang, C.W., Kang H.Y. 2012. FSP Mesurement of Heat-treated Hardwoods Using Volumetric Swelling Method, Journal of the Korea Funiture Society 23: 163-168. 10. Byun, H. S., Park, J. H., Park, H. M., Park, B. S., Jeong, S.H. 2008. Compression stregth and hardness of heat-treated wood, Proceedings of the Korean Society of Wood Science and Technology Annual meeting: 169-170. 11. Kamdem, D. P., Pizzi, A., Guyonnet, G., Jermannaud, A. 1999. Durability of heat-treated wood, The International Research Group on Wood Protection, IRG / WP 99-40145. 12. Won, K. R., Hong, N. Y., Kwon, S. S., Jeong, S. H., Byun, H. S. 2015. Application of heat-treated wood with heat medium, 2015. Proceedings of the Korean Society of Wood Science and Technology Annual Meeting, 344-345. 13. Hong, N.Y., Kwon, S.S., Jeong, S.H., Won, K.R., Byun, H.S. 2014. Decay of heat-treated wood by concentration of heat medium, 2014. Proceedings of the Korean Society of Wood Science and Technology Annual meeting: 320-321. 14. Ra, J. B., Kim, K. B., Lim, K.H. 2012. Effect of heat treatment conditions on color change and termite resistance of heat-treated wood, J. Korean Wood Sci. & Tech. 40 (6): 370-377. 15. Lee, S.J., Kang, S.K., Kang, C.W., Kang H.Y. 2012. FSP Mesurement of Heat-treated Hardwoods Using Volumetric Swelling Method, Journal of the Korea Funiture Society 23: 163-168. 16. Byun, H. S., Park, J. H., Park, H. M., Park, B. S., Jeong, S.H. 2008. Compression stregth and hardness of heat-treated wood, Proceedings of the Korean Society of Wood Science and Technology Annual meeting: 169-170. 17. Hong, B.H. 1986. Dynamic viscoelasticity of heat treated wood, J. Korean Wood Sci. & Tech. 14 (2): 2013-2020.

Wood, which is a hydrophilic polymer substance, loses the characteristics of high-density wood due to the springback phenomenon that is restored to a circular shape due to moisture absorption even when subjected to heat compression at high temperatures. Such degradation of dimensional stability due to moisture absorption may cause deformation or defects in use, which may cause problems in real life. In addition, although the domestic market is supplied with heat-treated wood in industry and there is a domestic research report on the heat treatment of wood, there is still a lack of research information on application of heat treatment to the domesticated domestic species.

Accordingly, the present invention provides a method for manufacturing compressed wood which can be applied to domesticated domestic species and can prevent spring back phenomenon due to moisture absorption of heat-compressed wood.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to a first aspect of the present invention, Impregnating the dried wood into the thermosetting resin; Drying the thermosetting resin-impregnated wood; Thermally compressing the dried wood at a temperature of 100 ° C to 180 ° C; And cooling and compressing the thermally compressed wood at a temperature of 25 캜 to 60 캜.

According to a second aspect of the present invention, there is provided a method of manufacturing a wood comprising: thermally compressing a wood at a temperature of 100 ° C to 200 ° C; Heat-treating the thermally compressed wood at a temperature of from 150 캜 to 270 캜; And aging the heat-treated wood for 1 day to 2 weeks. The present invention also provides a method for producing a compression-treated wood improved in dimensional stability.

The above-described task solution is merely exemplary and should not be construed as limiting the present disclosure. In addition to the exemplary implementations described above, there may be additional implementations and embodiments described in the drawings and detailed description of the invention

Conventionally, in order to stabilize the dimension of wood, a method of suppressing the adsorption of water by replacing a hydrophilic group with a high-temperature heat treatment or a chemical has been mainly used. In the present invention, a thermo-compression wood is produced in a state in which a part of the thermosetting resin is applied or not applied to the surface of the thermosetting resin by using a general hot press without using a chemical agent. Dimensional stabilization of thermally compressed wood was achieved.

The compression-processed wood which is produced by the present invention and is particularly suitable for use as a flooring material or a deck material having high dimensional stability against moisture contributes to carbon reduction and is eco-friendly. The natural wood is retained in its grain and pattern form, And since the compression plate itself has a very high hardness and strength, the compression plate itself is not damaged even when a strong impact is applied from the outside, and thus the merchandise and usability of the product can be greatly improved. Particularly, according to the method of the present invention, it is possible to efficiently apply to a low specific gravity coniferous material such as pine trees, and the manufacturing process can be simplified, which can shorten the production time and drastically reduce the labor cost and the manufacturing cost. Can be widely provided to consumers.

FIG. 1 is a photographic image showing the appearance according to the compression ratio of thermally compressed logs according to one embodiment of the present invention. FIG.
Fig. 2 is a schematic view showing the reaction mechanism between heat and wood components causing chemical conversion of wood components in the heat treatment process. Fig.
3 is a graph showing the relationship between the weight loss rate of heat treated wood and ASE.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly explain the present invention in the drawings, portions not related to the description are omitted.

Throughout this specification, when an element is referred to as " including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

The terms " about ", " substantially ", etc. used to the extent that they are used throughout the specification are intended to be taken to mean the approximation of the manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure. The word " step (or step) " or " step " used to the extent that it is used throughout the specification does not mean " step for.

Throughout this specification, the term " combination thereof " included in the expression of the machine form means one or more combinations or combinations selected from the group consisting of the constituents described in the expression of the machine form, And the like.

Throughout this specification, the description of "A and / or B" means "A, B, or A and B".

Hereinafter, a method of manufacturing compressed wood with improved dimensional stability of the present invention will be described in detail with reference to embodiments, examples and drawings. However, the present invention is not limited to these embodiments and examples and drawings.

According to a first aspect of the present invention, Impregnating the dried wood into the thermosetting resin; Drying the thermosetting resin-impregnated wood; Thermally compressing the dried wood at a temperature of 100 ° C to 180 ° C; And cooling and compressing the thermally compressed wood at a temperature of 25 캜 to 60 캜. For example, the thermal compression may be performed at a temperature of 130 ° C to 150 ° C, and / or the cooling compression may be performed at a temperature of 35 ° C to 45 ° C, but is not limited thereto.

According to one embodiment of the invention, the wood may be, but not limited to, a conifer material, in particular a domestic conifer material. For example, the conifer can include, but is not limited to, pine, pine and / or larch, and may be selected without limitation from coniferous trees known in the art. For example, the conifer material may have a shape such as a plate material or a wood material, but may not be limited thereto.

According to one embodiment of the present invention, the thermosetting resin may be, but not limited to, polyvinyl alcohol (PVA) or phenol-formaldehyde alcohol-soluble liquid resin. For example, the thermosetting resin may be a liquid resin adhesive.

According to an embodiment of the present invention, the step of impregnating the thermosetting resin may be performed using a thermosetting resin at 120 ° C to 150 ° C, but the present invention is not limited thereto. For example, the impregnation may be performed for about 20 to 30 minutes to cause the thermosetting resin to penetrate into the wood, but may not be limited thereto.

For example, the step of drying the wood into which the thermosetting resin is impregnated may be performed for about 3 to 4 hours, but may not be limited thereto, so that the adhesive used as the thermosetting resin is partially hardened.

According to an embodiment of the present invention, the thermal compression step or the cooling compression step may be performed by applying a pressure of 1,000 to 2,500 tons using a hydraulic cylinder, but may not be limited thereto. For example, the thermal compression may be performed for about 20 to 30 minutes, and / or the cooling compression may be performed for about 25 to 35 minutes, but may not be limited thereto.

According to one embodiment of the present disclosure, there is provided a method of manufacturing a composite material, comprising the steps of cutting the produced compressed work wood to an additional desired area and / or shape, forming it into a building or furniture material including a flooring or decking material, and / But may not be limited thereto.

The production method of the present invention may include, for example, a water drying step of drying a medium-sized light-weight domestic pine wood material to a moisture content of 12% or less; The dried wood board is poured into an impregnation tank containing a thermosetting resin PVA or phenol-formaldehyde alcohol-soluble liquid resin adhesive having an activation temperature of 120 to 150 ° C for about 20 to 30 minutes to uniformly infiltrate the adhesive into the tissue of the wood panel An adhesive impregnating step; An adhesive drying step in which the adhesive is dried for a predetermined time (for example, about 3 to 4 hours) so as to solidify part of the adhesive; Setting a predetermined amount of the wood plate material and uniformly spreading the same on a lower mold of a thermoforming press having a predetermined area; The hydraulic cylinder of the thermoforming press, in which the upper and lower mold temperatures are maintained at a constant temperature (for example, about 130 to 150 ° C) by the heater, is set to a predetermined pressure (for example, about 20 to 30 minutes) For example, about 1,000-2,500 tons), thereby curing the adhesive impregnated in the wood plate to form a compacted plate having a predetermined thickness and width; The hydraulic cylinder of the cooling press maintaining the upper and lower mold temperatures at a constant temperature (for example, about 35 to 45 DEG C) by the heater is maintained at a predetermined pressure (for example, about 25 to 35 minutes) To about 1000 to 2,500 tons) to prevent the change in the volume of the shaped compression sheet to have a predetermined thickness and width due to the curing of the adhesive; And cutting the compacted plate into a desired area and / or shape to form a building material or a furniture material including a flooring material or a deck material, and performing a surface finishing treatment. However, the present invention is not limited thereto, The steps need not necessarily be performed, and the order and specific conditions of the steps to be performed can be appropriately adjusted by a person skilled in the art.

According to a second aspect of the present invention, there is provided a method of manufacturing a wood comprising: thermally compressing a wood at a temperature of 100 ° C to 200 ° C; Heat-treating the thermally compressed wood at a temperature of from 150 캜 to 270 캜; And aging the heat-treated wood for 1 day to 2 weeks. The present invention also provides a method for producing a compression-treated wood improved in dimensional stability.

According to one embodiment of the invention, the wood may be, but not limited to, a conifer material, in particular a domestic conifer material. For example, the conifer can include, but is not limited to, pine, pine and / or larch, and may be selected without limitation from coniferous trees known in the art. For example, the conifer material may have a shape such as a plate material or a wood material, but may not be limited thereto.

For example, a step of processing natural wood with a sheet of desired size prior to thermally compressing the wood may be performed first.

For example, the thermal compression may be performed at a temperature of 120 ° C to 180 ° C, and may be performed for about 5 to 20 minutes, but the present invention is not limited thereto.

According to an embodiment of the present invention, the thermal compression may be performed so that the moisture content of the wood is 10% or less, but the present invention is not limited thereto.

According to an embodiment of the present invention, the heat treatment may be performed at a temperature of about 180 ° C to 240 ° C, and may be performed for a treatment time of about 24 hours or less, but the present invention is not limited thereto.

For example, the aging step can be carried out in an aging chamber in which temperature and humidity are kept constant.

For example, the method of manufacturing the compression-processed wood may further include cutting and / or processing the aged wood according to a desired use and / or standard, but the present invention is not limited thereto.

For example, the method of manufacturing the compressed working wood may further include, but not limited to, attaching the elastic member to one side or both sides of the produced compressed working wood.

According to one embodiment of the present application, it is further contemplated that the step of cutting the manufactured pressed wood to an additional desired area and / or shape, forming it into a building or furniture material comprising a flooring or decking, and / But may not be limited thereto.

The present invention is based on the finding that even though a single wood layer of softwood lumber, such as pine wood, is used for a long time by high-temperature thermal compaction treatment, the wood is not rotten and the conduction is smooth, so that heat loss is reduced And the dimensional stability is improved by lowering the rate of change due to moisture absorption.

The manufacturing method of the present invention may include, for example, a primary processing step of processing natural wood with a plate having a predetermined size; The processed plate material is placed in a thermo-hydraulic device for thermal compression, thermally compressed at a temperature of about 120 ° C to 180 ° C for about 5 to 20 minutes, and subjected to heat compaction so that the water content of the processed thermally compressed plate material is 10% Compression step; A high temperature heat treatment step of restraining the primary compressed sheet material with a fixture and putting the sheet material into a heat treatment chamber and heating the sheet material at a temperature between 180 ° C. and 240 ° C. for 24 hours or less; A thermally compressed wood aging step of storing and aging the heat-compressed thermally compressed wood in a maturing chamber having a constant temperature and humidity for a period of not more than one week; A secondary processing step of cutting and aging the aged thermally compressed wood into a standard material of a predetermined size in accordance with the specifications of various applications; And an elastic member attaching step of attaching a stretchable member made of elastic material to one side of the standard material. However, the present invention is not limited thereto, and all of the steps need not always be performed, And the specific conditions can be appropriately adjusted by a person skilled in the art.

The present invention also relates to a method of manufacturing a high-density wood material by making a high-density wood material by using a common pine wood as a material and transversely compressing the material by using a hot press, setting it on a jig and restraining it, Min to perform a short-time heat treatment, thereby providing a method of obtaining a dimensionally-stabilized compressed wood free from deformation due to moisture absorption.

In particular, the present invention relates to a method of producing a high-density wood by subjecting a low specific gravity Korean pine wood having a specific gravity of about 0.4 as a raw material to a surface to which a thermosetting resin is applied, But the present invention is not limited thereto. The present invention relates to a method of manufacturing compressed wood, which is excellent in dimensional stability, by restraining it to a jig and performing post heat treatment such as high frequency in a closed state or an open state in a state of being closed.

FIG. 1 is a photographic image showing the appearance according to the compression ratio of thermally compressed logs according to one embodiment of the present invention. FIG. From the left are 100% (log), 70%, 50%, and 30% thermal compression wood with a thickness compression ratio.

The purpose of the post-heat treatment herein is to cause the wood fiber to lose moisture activity due to deterioration of the constituents due to the high temperature treatment, an increase in the degree of crystallization of the cellulose, and lignin covering. The reaction mechanism between the heat and the wood components causing the chemical transformation of the wood components during the heat treatment is shown in FIG. 2 (Mayes and Oksanen, 2002). The main constituents of the wood are hemicellulose, cellulose, lignin, and extract components. As shown in FIG. 2, when heat is applied to the wood, hemicellulose is first pyrolyzed together with moisture release of the wood at an initial stage of about 120 ° C, and an acid such as acetic acid is produced. Formaldehyde, furfural and aldehyde are formed in the wood by the decomposition reaction by these acid catalysts, and the polymerization degree of the sugar polymer in the wood is reduced. At the same time, a dehydration reaction takes place with a decrease in hydroxyl groups in the hemicellulose, resulting in a decrease in the content of carbohydrates in the wood. It has also been reported that hemicellulose is more easily degraded than cellulose. When the temperature becomes higher and reaches 180 to 230 ° C, xylose and mannose decrease in the wood, and arabinose and galactose disappear almost. Since cellulose has a crystalline region, pyrolysis reaction is known to be relatively slow at the temperature at which hemicellulose is pyrolyzed. It has been reported that the cellulose amorphous region is first decomposed with increasing temperature in the wood, and the degree of crystallization of cellulose is increased and the size of crystal region is increased at around 230 ° C. As the degree of crystallization of cellulose increases, the number of hydroxyl groups accessible to water molecules decreases in cellulose, and as a result, the number of water molecules adsorbed on cellulose decreases, resulting in reduction of equilibrium moisture content and hygroscopicity. Such a phenomenon has the effect of increasing the dimensional stability of wood and weathering resistance against degraded organisms. At the same time, many polymer saccharides are lost in this process, resulting in a reduction in density due to weight reduction and a deterioration in mechanical performance. Lignin also causes cleavage of C? And O? Of lignin by the acid catalytic reaction generated by the decomposition of hemicellulose during the transition from 120 占 폚 to 230 占 폚, thereby generating formaldehyde furfuryl and aldehyde and the like, The self-condensation reaction of lignin is initiated. At this time, the number of reactors is increased to the aromatic ring of some lignin, and Cα of benzyl is cationized due to the separation of methoxyl group. In this case, a part of the aldehyde group which is an initial pyrolysis product is linked with methylene bridge Reacts with reactors in the aromatic ring. Although this reaction occurs moderately, it has been reported that lignin structure is changed by increasing cross-linking to lignin, resulting in reducing hygroscopicity in wood or increasing dimensional stability (Candelier et al., 2013; Esteves et al. Dirol and Guyonnet, 1993; Bourgois and Guyonnet, 1988). In addition, the heat treated wood tends to have higher lignin content than untreated wood. For this phenomenon, Esteves and Pereira (2009) suggested that the analytical method used in the heat-treated wood samples may not be pure lignin. In other words, lignin may be cross-linked to polycondensation reaction with components such as cellulose and hemicellulose during the heat treatment process and may have been measured as apparently having a large amount of lignin (Boonstra and Tjeerdsma, 2006; Esteves et al, 2008).

Extracts of wood extracts are pyrolyzed at 120 ~ 180 ℃ during heat treatment, and converted into new materials in wood to increase the extract. However, it has been reported that most of the extracts in wood are pyrolyzed and disappeared at high temperatures above 230 ° C. However, in practice, the analysis of heat treated wood results in higher values as the extract increases, which is presumably due to pyrolysis products of carbohydrates in the wood (Esteves and Pereira, 2009; Mayes and Oksanen, 2002; Militz, 2002; Kotilainen, 2000; Tjeerdsma et al., 1998a).

One of the great advantages of heat treated wood is that the hygroscopicity of wood due to changes in relative humidity in the atmosphere is lower than that of untreated wood and the dimensional stability is also significantly improved. When the temperature of the wood is increased by the heat treatment, the major component of the wood reacts to change the component, and the moisture absorption of the wood is considerably lower than that of the untreated wood because the exposure of the hydrophilic period is reduced.

In addition, the relationship between atmospheric humidity and the hygroscopicity of heat-treated European scraps (Scots pine) and beech (Tjeerdsma et al., 1998b) has been investigated. The hygroscopicity of wood is expressed by Equilibrium Moisture Content (EMC), and the changes of EMC are shown by adsorption and desorption curves of heat treated wood and untreated wood. In the case of heat treated European shipment and beech trees, the higher the relative humidity of the atmosphere in both species, the lower the EMC was significantly lower than the untreated material. Both species showed a similar decrease in EMC when adsorbed and desorbed, and both species showed a 30-45% reduction in hygroscopicity compared to untreated materials. However, when the heat treatment conditions used in the heat treatment process are different, the EMC changes of the heat treated wood are different (Millitz, 2002; Guo et al., 2014). Guo et al. (2014) tested the poplar and found that as the heating temperature increased from 170 ℃ to 230 ℃, the maximum EMC was 54.3% (230 ℃, 4 hours Treatment), and the hygroscopicity due to heat treatment remarkably decreases with increasing temperature and treatment time. Generally, the hygroscopicity decreases and the dimensional stability is increased when the fiber saturation point is lowered. The dimensional stability of wood is represented by the anti swelling efficiency (ASE).

The relationship between the weight loss rate of heat treated wood and ASE is shown in Fig. As shown here, ASE increases with increasing weight loss rate of heat treated wood, and ASE value increases with heating temperature at heat treatment. That is, the higher the heating temperature, the lower the hygroscopicity of wood and the better the effect of dimensional stability. The ASE of the heat treated wood depends on the heat treatment condition, but the ASE of the heat treated wood called the thermowood which is industrialized in Finland is about 50 ~ 90% compared to the untreated wood, the OHT heat treated wood of Germany is 20 ~ 40% (Ropes and Sailer, 2001; Vernois, 2001; Homan and Jorissen, 2004), while the Rectified wood of France and the Plato wood of the Netherlands have a synergistic effect of about 15 to 40% (Mayes and Oksanen, 2002; Ozkan et al. (2014) also showed that when OHT treatment was applied to Turkish fir, ASE reached 50% under optimum heat treatment conditions. Chaouch et al. (2012) reported different dimensional stability of about 34-48% in ASE for each species when treated with 5 species of coniferous and hardwood timber under the same conditions to give a weight loss of about 10%. Many other reports have recognized the effect of dimensional stability by reducing the hygroscopicity due to heat treatment (Talei et al., 2015; Sandberg et al., 2013; Bazyar et al., 2010; Fojutowski et al., 2009; Sailer et al. 2008; Welzbacher et al., 2009; Homan et al., 2004; MIlitz, 2002). However, some researchers pointed out the necessity of research on the relationship between the target species and the heat treatment process for industrialization, because the ASE was not obtained or the variation was severe when commercial heat treatment technology was applied to other species (Hamamda et al., 2015 ; Vidrine et al., 2007).

It will be understood by those of ordinary skill in the art that the foregoing description of the embodiments is for illustrative purposes and that those skilled in the art can easily modify the invention without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claims (10)

Drying the wood;
Impregnating the dried wood into the thermosetting resin;
Drying the thermosetting resin-impregnated wood;
Thermally compressing the dried wood at a temperature of 100 ° C to 180 ° C; And
Compressing the thermally compressed wood at a temperature of from 25 캜 to 60 캜.
A method for manufacturing compressed wood having improved dimensional stability.
The method according to claim 1,
Wherein the wood is a softwood, and the dimensional stability is improved.
The method according to claim 1,
Wherein the thermosetting resin is a liquid resin for polyvinyl alcohol (PVA) or a phenol-formaldehyde alcohol, wherein the thermosetting resin is improved in dimensional stability.
The method according to claim 1,
Wherein the step of impregnating the thermosetting resin is performed by using a thermosetting resin at 120 ° C to 150 ° C.
The method according to claim 1,
Wherein the thermal compression step or the cooling compression step is performed by applying a pressure of 1,000 to 2,500 tons using a hydraulic cylinder.
Thermally compressing the wood at a temperature of 100 ° C to 200 ° C;
Heat-treating the thermally compressed wood at a temperature of from 150 캜 to 270 캜; And
And aging the heat treated wood for 1 to 2 weeks.
A method for manufacturing compressed wood having improved dimensional stability.
The method according to claim 6,
Wherein the wood is a softwood, and the dimensional stability is improved.
The method according to claim 6,
Wherein the heat compressing step is performed so that the water content of the wood becomes 10% or less.
The method according to claim 6,
Wherein the heat treatment is performed for a treatment time of 24 hours or less.
The method according to claim 6,
And attaching the elastic member to one side or both sides of the manufactured compressed working wood.

Images