KR101380099B1 - Manufacturing Method for Carbonized Wood Using Heat Treatment - Google Patents

Abstract

The present invention relates to a method for producing a heat-treated carbon wood, which comprises a wood screening step (S100) for screening according to the size of the wood; Wood input step (S200) for inputting the selected wood to the dryer; A temperature raising step (S300) of raising the temperature inside the dryer to a heating target temperature; A temperature maintaining step (S400) of maintaining a temperature inside a dryer at the heating target temperature; A cooling step (S500) of cooling the temperature inside the dryer to a cooling target temperature after the temperature maintaining step (S400); It is characterized by including a processing step (S600) of taking out the wood input into the dryer and processing it into wood products.
By the configuration as described above the present invention can heat the wood to induce a change in color, and at the same time by using the advantages of charcoal and wood to produce an effective wood to remove the odor and bacteria in the room and humidity control.

Description

Manufacturing Method for Carbonized Wood Using Heat Treatment

The present invention relates to a method of manufacturing heat-treated carbon wood, more specifically, it is possible to give a change in color through heat treatment without adding a separate chemical to the wood, air purification ability and indoor odor removal and bacteria removal effect The present invention relates to a heat-treated carbon production method for producing carbonized wood having a humidity control effect.

Generally, wood undergoes various processing depending on product shape or performance from logging until completion to a specific product. Among these processing processes, it is a process that greatly affects product quality and production cost. Processing and dry processing are mentioned.

In particular, the conventional drying process has a disadvantage in that the resin in the wood remains intact by drying the wood over a long period of time or hot air drying in a drying room or a dryer for a short period of time.

In addition, the low-grade wood of bright colors such as pine, pine, larch, and birch, which we commonly see in relation to the characteristics of wood, has the disadvantage of discoloring easily in ultraviolet rays, and it is not easy to color during painting process. Therefore, low-grade timber, which is bright in color, is not used in various fields like high-quality hardwoods.

In order to solve this problem, Patent No. 524434 (method for producing modified wood) has been proposed. This technique is performed by applying the wood in a high pressure steam at 120 to 200 ° C. and a pressure of 0.2 to 1.6 MPa as shown in FIG. 1. By holding it for 1 to 60 minutes, it is possible to change the color of wood without the use of chemicals. Since small wood is the object of treatment, the color change can be evenly applied when the above technique is applied to large wood. There is a disadvantage.

The present invention has been made to solve the problems of the prior art as described above, it is possible to change the color of the small or large wood without a separate chemical treatment, and at the same time using the advantages of carbide and wood The purpose of the present invention is to provide a method for producing heat-treated carbon wood that is effective in removing odors, removing bacteria, and controlling humidity.

The object of the present invention as described above is a method for producing carbonized wood, the wood screening step of selecting according to the size of the wood; A wood input step of inputting the selected wood to a dryer; A temperature raising step of raising the temperature inside the dryer to a heating target temperature; A temperature maintaining step of maintaining a temperature inside the dryer at the heating target temperature; A cooling step of cooling the temperature inside the dryer to a cooling target temperature after the temperature maintaining step; It is achieved by constructing a processing step of taking out the wood introduced into the dryer and processing into wood products.

At this time, the internal pressure of the dryer is carried out to maintain a pressure of 0.3 ~ 2 atm higher than atmospheric pressure.

In addition, nitrogen gas (N ₂ gas) or superheated steam may be injected into the dryer intermittently.

In addition, the heating target temperature is 160 ~ 250 ℃, in the temperature increase step may be carried out by controlling the dryer to reach the heating target temperature by increasing the temperature step by step for 1 to 3 hours.

The temperature maintaining step may be performed by controlling the dryer so that the heating target temperature is kept constant for 6 to 10 hours.

On the other hand, in the cooling step may be carried out by slow cooling over the 3 to 4 hours from the heating target temperature to the cooling target temperature by the air cooling method, the cooling target temperature at this time may be carried out to be 50 ~ 60 ℃. .

In addition, the wood product may be implemented as any one of a clock, a normal closing, a molding material, an ornament, an indoor air purifying article.

According to the present invention, as a technique for artificially changing the color of the wood without additives according to the treatment process proposed in the present invention by controlling the heat treatment time within the temperature range of 160 ~ 250 ℃ to change various kinds of natural wood to the desired color Can be.

It also has the advantage of producing intermediate products of wood and charcoal with air purification as well as the effect of changing the color of wood.

In addition, the color change wood produced according to the color change and drying method of the wood is not only luxurious because the surface and the inner layer of the wood is changed to the same dark color, but also has the advantage that impurities in the wood are removed during the heat treatment process.

On the other hand, by alternately pasting the color change wood and natural wood of the same species produced by the present invention can make a more diverse feeling of aggregate wood, whereby the properties of the color change wood and natural wood is almost the same as that made of only natural wood There are also features that can have the same durability.

Figure 1 shows a method of manufacturing a conventional modified wood
Figure 2 is a schematic view showing a heat treatment carbonized wood manufacturing method according to the present invention,
3 is a graph showing the temperature change of the dryer of the heat treatment carbonaceous wood manufacturing method according to the present invention,
Figure 4 is a photograph comparing the change in color of the blue stained ridge pine,
5 to 8 is a photograph showing an embodiment of a wooden product using a heat treatment carbonized wood manufacturing method according to the present invention,
9 to 12 are graphs showing adsorption isotherm curves of pine, pine, larch, and birch, respectively,
13 is a view showing an example of the position of measuring the surface hardness of the wood piece prepared for the surface hardness measurement experiment,
14 is a graph showing the change in surface hardness by heat treatment time obtained through the surface hardness measurement experiment,
15 to 17 is a graph showing the change in brightness, redness, yellowness according to the outdoor exposure test of pine, respectively,
18 to 20 are graphs showing changes in brightness, redness, and yellowness according to the outdoor exposure test of pine trees,
21 to 23 are graphs showing changes in brightness, redness, and yellowness according to the outdoor exposure test of larch, respectively;
24 to 26 are graphs showing changes in brightness, redness, and yellowness according to the outdoor exposure test of birch trees,
27 to 29 are graphs showing changes in brightness, redness, and yellowness according to the outdoor exposure test of Rigida pine, respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described more fully with reference to the accompanying drawings, in which preferred embodiments of the invention are shown.

The present invention relates to a method of manufacturing carbonized wood by heat treatment to change the color of a large wood without chemical treatment, and to expect the efficacy of carbide, as shown in Figure 2 wood selection step (S100) ), The wood input step (S200), the temperature rising step (S300), the temperature maintaining step (S400), the cooling step (S500) and the processing step (S600) is made, each step will be described in more detail below.

(1) Wood sorting step (S100)

This step is to cut the timber to a suitable length that can be introduced into the dryer or to select a large timber, in some cases it may include the sorting of wood by type.

(2) wood input step (S200)

This step is a step of injecting the selected wood into the dryer, the process includes placing the wood evenly dried in the dryer.

(3) heating step (S300)

This step is a preliminary step in which the wood is exposed to a high temperature environment in the dryer for a long time by raising the temperature inside the dryer to a heating target temperature, where the internal pressure of the dryer is 0.3 to 2 atmospheres higher than atmospheric pressure. It is set to be maintained, and the temperature is raised in an oxygen-free or low concentration oxygen atmosphere while intermittently injecting nitrogen gas (N ₂ gas) or superheated steam.

In general, when wood composed of cellulose, hemicellulose, lignin, etc. is exposed to a suitable temperature, a millard reaction occurs and the color (color) is gradually increased, and when exposed to a temperature that is too high, the air (oxygen) is blocked. The wood is not charred but charcoal.

In other words, if the wood is heat-treated at a temperature where the millard reaction occurs in a low oxygen atmosphere where air is shut off for a suitable time, the color change and drying are carried out, and a part of the surface layer of the wood is obtained between the carbonized wood and char. .

Therefore, the present inventors focus on this point, and through a myriad of repeated experiments, the color change is good when the heating target temperature of the wood is 150-250 ° C, and the intermediate form of carbonized wood and charcoal can be obtained. In the case of applying to, it was confirmed that the color change uniformly.

Therefore, in the temperature increase step (S300), the internal temperature of the dryer is raised to 150 ~ 250 ℃, at this time, it is preferable to increase the temperature step by step so that it takes 1 to 3 hours to reach the heating target temperature at room temperature.

(4) temperature maintenance step (S400)

This step is to maintain a constant temperature for 6 ~ 10 hours inside the dryer raised to the target heating temperature, thereby obtaining an intermediate form of carbon and charcoal in which a portion of the surface layer of the wood is carbonized.

(5) cooling step (S500)

This step is to complete the drying by cooling the temperature inside the dryer to the cooling target temperature over 3 to 4 hours after the temperature maintenance step (S400), in this step 50 to 60 ℃ at the heating target temperature by air cooling method Slow cooling to the cooling target temperature to reach.

(6) Machining Step (S600)

This step is a step of making a wood product by processing the cooled wood, in the present invention is used as a wooden product such as watches, ordinary closing, molding materials, ornaments, indoor air conditioning supplies.

Hereinafter will be described in detail through an experimental example of drying various wood through the above manufacturing method.

<Examples>

Figure 3 is a heat treatment time-temperature graph when treating the hardwood of 50 thickness according to the color change and drying method according to the present invention.

In the dryer used in the experiment of the present invention, nitrogen gas injection means may be used instead of the superheated steam generator. The nitrogen gas injection means may be constituted by, for example, a gas pipe and a nitrogen gas cylinder in which a solenoid valve is controlled to be opened and closed by the controller. Alternatively, the conventional dryer may be used by installing a superheated steam generator or nitrogen gas injection means.

In addition, the dryer can be operated by varying the internal temperature and heat treatment time of the working chamber according to the type of wood to be processed and the degree of color change.

For example, the internal temperature is maintained at 160 to 260 ° C, and the internal pressure is slightly higher than atmospheric pressure but does not exceed 3 atm. It can be heat treated within the range.

In addition, while maintaining the internal pressure about 0.3 atm above atmospheric pressure to prevent air from entering the dryer, allow the internal temperature of the working chamber to rise to 220 ° C within 2 hours after the start of operation, and then at 220 ° C for about 10 hours. The internal temperature of the working chamber was reached to 50 ° C. over about 4 hours.

As a result of this operation, drying occurred during the contact between the superheated steam and the wood. At this time, impurities such as volatile organic compounds and resins in the wood were substantially removed, thereby improving the defects of the wood and improving the dimensional stability.

In addition, the surface contamination and the internal stress of the wood were removed during the superheated steam, so that the wood with excellent durability and color change that was not easily discolored even under ultraviolet light was obtained.

Figure 4 is an exemplary case of the surface contamination of the wood is removed, showing a comparison picture when the blue-contaminated green pine pine treated according to the method of the present invention and when no treatment.

In addition, according to the present invention, even the wood of the same species can obtain a variety of color change wood according to the type of material or heat treatment conditions, it can be used to manufacture a variety of ornaments and wood products, for example as the ash color change of the ash wood of Figure 5 Can make a wall clock or a plaque, and can also be used as a molding material by changing the color of the domestic coniferous material (pine and larch) as shown in FIG.

In addition, as shown in Figure 7 can be combined with alternating wood and natural wood alternately to make the aggregate wood for building interior materials or furniture materials, as shown in Figure 8 can also be made in the form of charcoal trilogy, charcoal trilogy is the indoor odor It is not only useful for removing germs and controlling humidity, but also can be used as indoor decoration because bark (bark) keeps its natural beauty.

On the other hand, the wood exposed to high temperature loses the adsorption point, so the equilibrium moisture content is lowered and thus the dimensional stability is increased. Therefore, the present inventors have measured the equilibrium moisture content under various relative humidity conditions in order to measure the degree of dimensional stability of the wood heat-treated at 220 ° C. Was measured to determine the adsorption isotherm. At this time, the target of the dimensional stabilization experiment was composed of pine, pine, larch, and birch, and specific experimental conditions are as follows.

end. Dimensional Stabilization Experiment

Remove six 6 mm specimens from the middle of the heat treated 800 mm wood pieces, and place the 6 mm specimens in the desiccator with saturated salt solution in Table 1 below to achieve equilibrium relative humidity at 20 ° C. It was left for months.

Relative Humidity (%) Salt solution 32.0

58.0

80.5

90.0

95.0

100.0

The result graph of the adsorption isotherm curve for each material heat-treated at 220 ° C is as follows. In this graph, the number after the slash (/) indicates the processing time.

Figure 9 is a graph showing the adsorption isotherm curve of pine, Figure 10 is a graph showing the adsorption isotherm curve of pine, Figure 11 is a graph showing the adsorption isotherm curve of larch, Figure 12 is a graph showing the adsorption isotherm curve of birch It is a graph.

The equilibrium moisture content was compared by treatment time, and the equilibrium moisture content of 95% relative humidity was compared because the capillary condensation water was not obtained at 100% relative humidity. The results are shown in Table 2 below.

Species

Equilibrium moisture content by treatment time (%) at 95% relative humidity 2 3 6 8 10 12 Maximum car Pine tree 18.7 19.3 20.0 17.1 13.5 16.2 6.5 Pine tree 19.6 19.5 21.5 20.5 17.8 16.0 5.4 larch 20.6 18.2 17.5 18.0 20.7 14.6 6.1 Birch 23.4 22.7 21.6 20.9 13.5 9.8

Since the 800mm wood piece was not heat treated evenly as a whole, it showed a slightly different heat treatment condition depending on where the 6mm specimens were cut out, but the uniform experimental results were not obtained. However, the longer the heat treatment time, the lower the equilibrium moisture content. The difference in the equilibrium moisture content was the smallest (5.4%), the birch was the largest (9.8%), and the difference in the equilibrium moisture content was improved due to poor adsorption.

I. Surface Hardness Measurement Experiment

After preparing three pieces of wood for each material, different heat treatment times were performed at 220 ° C., and specimens of 10 cm in length and 20 cm in width were collected from the pieces of wood, respectively. Was measured.

 Rockwell hardness tester model DTR-300, 1/2 inch ball was used as the surface hardness measurement device, and 30 kg load was applied. The surface hardness change according to the heat treatment time of pine, pine, larch, and birch was Same as the graph of 14.

 Since the graph of FIG. 14 shows the negative depth of the ball, the surface hardness is relatively high at the top of the graph. As a result, the surface hardness of the birch is the largest and the other three conifers have similar surface hardness. Can be.

In addition, the surface hardness of both species was similar to the treatment time of 2 hours and 12 hours, and the treatment time between them was higher than those of 2 hours and 12 hours, especially when the heat treatment was performed for 8 hours.

Therefore, it can be seen from these results that the surface hardness is temporarily increased by heat treatment, but when the treatment time is longer, thermal decomposition occurs and the surface hardness is decreased.

All. Outdoor exposure experiment

Recolor Change Wood has the potential to discolor faster than untreated wood (natural wood) when exposed to UV light because cellulose and lignin are degraded by heat during heat treatment.

Accordingly, the inventors made pine, pine, larch, birch, and rigi pine tree specimens subjected to the color change treatment (heat treatment) at 220 ° C. to 10 cm long and 20 cm wide, from July 30, 2005 to September the same year. It was exposed to the sun for 42 days until 10 days.

In addition, in the case of rain because there is no roof, the color was not measured for a few days after the rain. The color was measured using a HUNTER color difference meter after cutting the surface of wood with a hydraulic planer.

① pine

As shown in the graph of FIG. 15, immediately after the heat treatment, the brightness difference was severe depending on the treatment time, but after exposure to 42 days, all the specimens showed the same value as the initial brightness of the treated material for 12 hours.

In addition, as shown in the graph of FIG. 16, the redness decreases as the outdoor exposure time becomes longer. Since the 25th day has been relatively stable, the redness deviation according to the heat treatment time was maintained from the beginning to the end.

In addition, as shown in the graph of FIG. 17, the yellowness also decreased continuously from the beginning, as in the redness, and was stabilized after 25 days.

② pine tree

As shown in the graph of FIG. 18, the lightness difference was large according to the treatment time immediately after the heat treatment, but after 42 days of exposure, all the specimens were similar, but there were still differences according to the heat treatment time.

Also, as shown in the graph of FIG. 19, the redness difference was remarkable immediately after the heat treatment, but after exposure to 42 days, the redness value was collected. However, there was still a difference in redness between the specimens and the highest redness during the 12-hour heat treatment.

On the other hand, the difference in the initial yellowness compared to the lightness or redness was not as large as shown in the graph of FIG.

③ larch

As shown in the graph of FIG. 21, the initial brightness was clearly different from the heat treatment time of 10 hours or more, but after 42 days of exposure, the difference was reduced but the variation was much reduced. And after 42 days of exposure, the brightness of all specimens approached the initial values of 10 and 12 hours treated wood.

In addition, the redness with treatment time immediately after heat treatment showed a large difference as shown in the graph of FIG. 22, but the difference was reduced after 42 days of exposure. However, there was still a variation according to the treatment time.

In addition, as shown in the graph of FIG. 23, the initial difference between the yellowness and the specimen decreased after the exposure, while the yellowness of the 10-hour and 12-hour treated wood decreased steadily, but the remainder remained the same. It was.

④ birch

In the graph of FIG. 24, the BR220 / 12 (special) specimen was a particularly dark specimen even though the treatment time was the same. Immediately after heat treatment, the brightness showed a big difference according to the treatment time, but after 42 days of exposure, all specimens showed almost the same brightness except for 12 hours of treated wood.

In addition, as shown in the graph of FIG. 25, the redness of the specimen was reversed only at the beginning and the end of the exposure, but the deviation was almost the same. In particular, the redness of the BR220 / 12 (special) specimens was hardly changed by the exposure.

As shown in the graph of FIG. 26, there was no significant difference in the initial yellowness except for the BR220 / 12 (special) specimen, and after 42 days of exposure, the ranking was reversed, but the deviation was similar to the initial one.

⑤ Rigida pine

As shown in the graph of FIG. 27, the color change wood and the untreated wood immediately after heat treatment had a large difference in brightness, and after 42 days of exposure, the difference was only slightly reduced and still differed. In addition, 45-thick specimens showed similar brightness over the exposure period.

The redness was rapidly reduced to 25 days and then stabilized as shown in the graph of FIG. 28. The redness of the untreated wood (natural wood) showed similar values at the beginning and the end of the exposure.

In addition, the yellowness was continuously decreased from the initial exposure as shown in the graph of FIG. 29, but the untreated wood was decreased after maintaining the initial value until 20 days.

In other words, it can be seen that discoloration of untreated wood begins to occur after a certain period of time.

As described above, the wood produced by the present invention is environmentally friendly due to the disappearance of volatile organic compounds, and can be used as an outdoor building material because of high dimensional stability due to heat treatment, and is a human-friendly material that does not require coloring.

And since it has both advantages as an intermediate form of charcoal and wood, it is effective in removing odors, germs, and humidity control, and the bark is preserved as it is to maintain beauty like natural wood.

Claims (8)

Wood sorting step (S100) for sorting according to the size of the wood;
A wood input step (S200) for inputting the selected wood to a dryer;
A temperature raising step (S300) of raising the temperature inside the dryer to a heating target temperature of 150 to 250 ° C;
A temperature maintaining step (S400) of maintaining a temperature inside the dryer at the heating target temperature;
A cooling step (S500) of cooling the temperature inside the dryer to a cooling target temperature after the temperature maintaining step (S400);
Including a processing step (S600) for taking out the wood put into the dryer and processing into a wood product,
The internal pressure of the dryer is maintained at a pressure of 0.3 to 2 atmospheres higher than atmospheric pressure,
In the temperature raising step S300, the temperature is gradually increased for 1 to 3 hours to control the heating target temperature, and in the temperature maintaining step S400, the heating target temperature is kept constant for 6 to 10 hours. Controlled so that part of the surface layer of wood is halfway between carbonized wood and charcoal,
In the cooling step (S500) by the air cooling method heat treatment carbonized wood production method, characterized in that the slow cooling for 3 to 4 hours from the heating target temperature to the cooling target temperature.
delete The method according to claim 1,
Method of producing a heat-treated carbon wood, characterized in that the intermittent nitrogen gas (N ₂ gas) or superheated steam is injected into the dryer.
delete delete delete The method according to claim 1 or 3,
The cooling target temperature is 50 ~ 60 ℃ heat treatment carbon production method characterized in that the wood.
The method according to claim 1,
The wood product is a method of manufacturing a heat-treated carbon wood, characterized in that any one of a clock, a normal closing, a molding material, an ornament, an indoor air purification article.

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