Method for softening and slicing of a very hard wood

Abstract

This invention relates to the field of wood processing technology, and provides a novel method for preparing slicing from the decay and softening of extra-hardwood. The method includes the following steps: immersing a wood sample in a water-filled container, first applying a vacuum, then depressurizing and maintaining the pressure for a period of time to allow liquid water to penetrate the wood cell cavities; heating the immersed sample and applying a vacuum again to cause the liquid water to boil and vaporize; extracting the sample after the bursting treatment with cold and hot water sequentially to remove extractives from the wood and reduce its decay resistance; adjusting the moisture content; treating the sample with brown rot fungi to cause decay and softening on the axial surface of the sample; soaking the sample in water and then freezing it until it is solid, followed by slicing. This invention can successfully produce slicings of extra-hardwood, providing a strong theoretical foundation and technical means for studying the structure of extra-hardwood, predicting its physical and mechanical properties, and improving its high-value-added processing and utilization.

Description

Technical Field

[0001] This invention relates to the field of wood processing technology, and in particular to a method for producing slices from decayed and softened extra-hard wood. Background Technology

[0002] To improve the hardwood, especially extra-hardwood (density greater than 1.0 g / cm³) -3 To improve the high-value-added processing and utilization of timber (such as ebony and Hainan zijing), and to alleviate the contradiction between timber supply and demand in my country, researching and testing the structural characteristics of hardwoods and other woody materials naturally becomes a necessary prerequisite and foundation.

[0003] However, due to the hardness and weight of hardwoods, especially extra-hardwoods, softening is very difficult. Although some studies have reported that "extra-hardwoods can be glued onto ordinary glass, polished with sandpaper, and then polished with ordinary glass before slicing", there have been no truly successful cases to date.

[0004] Therefore, there is an urgent need to develop a new method for preparing softened slices of extra-hard wood, making it possible to slice extra-hard wood. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a new method for producing slices from decayed and softened hardwoods, so as to solve the problem that it is difficult to produce slices from hardwoods in the prior art. This provides a strong theoretical basis and technical means for studying the structure of hardwoods, predicting their physical and mechanical properties, and improving their high-value-added processing and utilization.

[0006] The present invention solves the above-mentioned technical problems by adopting the following technical solutions:

[0007] A novel method for producing slices from decayed and softened extra-hard wood includes the following steps:

[0008] S1, Vacuum Immersion

[0009] The hardwood to be cut (such as ebony, density 1.167 g / cm³) -3 Hainan Zijing, density 1.05 g / cm³ -3 (etc.) A sample of a certain length is cut and immersed in a container of water. First, a vacuum is drawn to 8.5 × 10⁻⁶. 4 ~9.5×10 4 Pa, then depressurize and maintain for 25-35 minutes to allow liquid water to fully penetrate the wood cell cavities;

[0010] S2, Explosives Treatment

[0011] After heating the water-immersed sample to 45-55℃, a vacuum of 9.5×10⁻⁶ was applied. 3 ~1.5×10 4Pa causes liquid water to boil and vaporize rapidly. The generated water vapor breaks through the pit membrane on the cell wall and opens up the channels between cells, improving the permeability of the wood. At the same time, it avoids the possibility of cracking due to the reduction of sample strength caused by high temperature.

[0012] S3, Hot and Cold Water Extraction

[0013] The samples after the blasting treatment were extracted with cold and hot water for 2.5 to 3.5 hours respectively to remove the extracts contained in the wood and reduce the wood's resistance to decay.

[0014] S4. Adjust moisture content

[0015] Place the sample in a temperature and humidity control chamber and set the dry and wet bulb temperatures to 28~32℃ and 19~23℃ respectively, and adjust them to the equilibrium moisture content to facilitate the subsequent decomposition of the decayed wood sample by brown rot fungi.

[0016] S5, The sample became soft and decayed due to bacterial infection.

[0017] Treat the sample with brown rot fungi (such as Cotyledon tomentosa) to cause the axial surface of the sample to decay and soften.

[0018] S6, Frozen Slices

[0019] The sample is soaked in water and then frozen until it freezes, so that the decayed and softened parts of the sample can gain a certain supporting strength before it is sliced.

[0020] As one of the preferred embodiments of the present invention, in step S1, a vacuum is drawn to 9.0 × 10⁻⁶ in a vacuum drying oven. 4 Pa, then decompress and keep for 30 minutes.

[0021] As one of the preferred embodiments of the present invention, in step S2, the water-immersed sample is placed in a vacuum drying oven and heated to 50°C, and then evacuated to a vacuum of 1.2 × 10⁻⁶. 4 Pa.

[0022] As one of the preferred embodiments of the present invention, in step S3, the sample is extracted for 3 hours each with cold water at 25°C and hot water at 100°C.

[0023] As one of the preferred embodiments of the present invention, in step S3, the extracts contained in the wood include tannins, resins, aromatic oils, alkaloids, and tannins.

[0024] As one of the preferred embodiments of the present invention, in step S4, the sample is placed in a temperature and humidity control chamber, and the dry and wet bulb temperatures are set to 30°C and 21°C respectively. The equilibration treatment lasts for no less than 2 days until the final moisture content is 44.5%~45.5%.

[0025] As one of the preferred embodiments of the present invention, in step S5, the sample is subjected to fungal decay for 5 days in a weakly acidic environment with a temperature of 28°C and a pH of 6 and with oxygen. The axial surface of the sample is decayed due to the decomposition of cellulose and hemicellulose by the fungi until the surface feels soft when gently pressed with a glass rod.

[0026] As one of the preferred embodiments of the present invention, in step S6, the sample is soaked in water and then placed in the freezer until it freezes, and then sliced ​​using a slicer.

[0027] As one of the preferred embodiments of the present invention, in step S6, since lignin is retained in the cell wall of the sample, the original shape and size of the cells are maintained. The resulting slices can be made into permanent slices for preservation or used as temporary slices for observation and statistical analysis.

[0028] As one of the preferred embodiments of the present invention, the extra-hardwood refers to wood with a density greater than 1.0 g / cm³. -3 Timber.

[0029] The advantages of this invention compared to the prior art are:

[0030] (1) The present invention firstly treats the extra-hardwood with “vacuum water immersion + explosion treatment” to rapidly boil and vaporize the liquid water in the wood, open up the intercellular channels and improve the permeability of the wood; then, the wood is further reduced in its resistance to decay by “hot and cold water extraction” of the sample after explosion treatment; based on the above treatment, the workability (decay and softenability) of the wood is greatly improved. At this time, the axial surface of the sample is decayed and softened by “adjusting the moisture content of the sample + brown rot fungus treatment”; finally, the sample is sliced; the method of the present invention can successfully achieve the slicing of extra-hardwood, and the slice quality is far superior to that of the prior art, providing a strong theoretical basis and technical means for studying the structure of extra-hardwood, predicting its physical and mechanical properties and improving its high-value-added processing and utilization.

[0031] (2) In the blasting process of the present invention, vacuum treatment is used; here, combined with vacuum treatment, the heating temperature of the sample can be reduced, so that the liquid water can boil and vaporize normally and quickly, while avoiding the possibility of cracking caused by the reduction of sample strength due to high temperature.

[0032] (3) In the freezing sectioning step of the present invention, the sample is soaked in water and then frozen until it freezes, so that the decayed and softened part of the sample can obtain a certain support strength, making it easier to slice it with a slicer. Attached Figure Description

[0033] Picture 1 This is a flowchart of the steps in the new method for preparing slices from the decay and softening of extra-hard wood in Examples 1-3. Detailed Implementation

[0034] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. Furthermore, unless otherwise specified, the methods used in the following embodiments are conventional methods known to those skilled in the art, and the materials used, unless otherwise specified, are commercially available products.

[0035] Example 1

[0036] This embodiment presents a novel method for preparing slices from decayed and softened extra-hard wood, such as... Picture 1 As shown, it includes the following steps:

[0037] S1, Sample Preparation

[0038] Hardwood to be cut (Hainan Zijing) Madhuca hainanensis Density 1.05 g / cm³ -3 Cut a sample with a length × width × thickness of 2.0 × 1.0 × 1.0 cm (length in the direction of the grain) for later use.

[0039] S2, Vacuum Immersion

[0040] The sample was immersed in a beaker filled with water, and a vacuum was drawn to 8.5 × 10⁻⁶ in a vacuum drying oven. 4 Pa, then depressurize and maintain for 35 minutes to allow liquid water to fully penetrate the wood cell cavities.

[0041] S3, Explosives Treatment

[0042] After heating the water-immersed sample to 45°C, a vacuum of 9.5 × 10⁻⁶ was applied. 3 Pa causes liquid water to boil and vaporize rapidly. The resulting water vapor breaks through the pit membrane on the cell wall, opening up channels between cells and improving the permeability of the wood. At the same time, it avoids the possibility of cracking due to the reduction of sample strength caused by high temperature.

[0043] S4, Hot and Cold Water Extraction

[0044] The samples after the blasting treatment were extracted with cold water at 25℃ and hot water at 100℃ for 2.5 hours each time to remove the extracts (tannins, resins, aromatic oils, alkaloids, tannins) contained in the wood and reduce the wood's resistance to decay.

[0045] S5. Adjust moisture content

[0046] The samples were placed in a temperature and humidity control chamber, and the dry and wet bulb temperatures were set to 28℃ and 19℃ respectively. The equilibration treatment lasted for no less than 2 days, and the moisture content was adjusted to 44.5% to facilitate the subsequent decomposition of the decayed wood samples by *Pothomocybe molluscioides*.

[0047] S6, The sample became soft due to bacterial decay.

[0048] Under a slightly acidic environment (pH 6) and with oxygen, at a temperature of 28℃, the *Polyporus flocculationii* was used... Poria vaporaria Allow the sample to decay for 5 days; the axial surface of the sample will decay due to the decomposition of cellulose and hemicellulose by *Potentilla chinensis* until the surface feels soft when gently pressed with a glass rod.

[0049] S7, Frozen Slices

[0050] After soaking the sample in water, it is placed in the freezer until it freezes, allowing the decayed and softened parts of the sample to gain some support strength. Then, it is sliced ​​using a microtome. Because the lignin in the cell walls of the sample is retained, the original shape and size of the cells are preserved. The resulting slices can be made into permanent sections for preservation or used as temporary sections for observation and statistical analysis.

[0051] Example 2

[0052] This embodiment presents a novel method for preparing slices from decayed and softened extra-hard wood, such as... Picture 1 As shown, it includes the following steps:

[0053] S1, Sample Preparation

[0054] Hardwood to be cut (Hainan Zijing) Madhuca hainanensis Density 1.05 g / cm³ -3 Cut a sample with a length × width × thickness of 2.0 × 1.0 × 1.0 cm (length in the direction of the grain) for later use.

[0055] S2, Vacuum Immersion

[0056] The sample was immersed in a beaker filled with water, and a vacuum was drawn to 9.0 × 10⁻⁶ in a vacuum drying oven. 4 Pa, then depressurize and maintain for 30 minutes to allow liquid water to fully penetrate the wood cell cavities.

[0057] S3, Explosives Treatment

[0058] After heating the water-immersed sample to 50°C, a vacuum of 1.2 × 10⁻⁶ was applied. 4 Pa causes liquid water to boil and vaporize rapidly. The resulting water vapor breaks through the pit membrane on the cell wall, opening up channels between cells and improving the permeability of the wood. At the same time, it avoids the possibility of cracking due to the reduction of sample strength caused by high temperature.

[0059] S4, Hot and Cold Water Extraction

[0060] The samples after the blasting treatment were extracted with cold water at 25℃ and hot water at 100℃ for 3 hours each time to remove the extracts (tannins, resins, aromatic oils, alkaloids, tannins) contained in the wood and reduce the wood's resistance to decay.

[0061] S5. Adjust moisture content

[0062] The samples were placed in a temperature and humidity control chamber, and the dry and wet bulb temperatures were set to 30℃ and 21℃ respectively. The equilibration treatment lasted for no less than 2 days, and the moisture content was adjusted to 45% to facilitate the subsequent decomposition of the decayed wood samples by *Potentilla chinensis*.

[0063] S6, The sample became soft due to bacterial decay.

[0064] Under a slightly acidic environment (pH 6) and with oxygen, at a temperature of 28℃, the *Polyporus flocculationii* was used... Poria vaporaria Allow the sample to decay for 5 days; the axial surface of the sample will decay due to the decomposition of cellulose and hemicellulose by *Potentilla chinensis* until the surface feels soft when gently pressed with a glass rod.

[0065] S7, Frozen Slices

[0066] After soaking the sample in water, it is placed in the freezer until it freezes, allowing the decayed and softened parts of the sample to gain some support strength. Then, it is sliced ​​using a microtome. Because the lignin in the cell walls of the sample is retained, the original shape and size of the cells are preserved. The resulting slices can be made into permanent sections for preservation or used as temporary sections for observation and statistical analysis.

[0067] Example 3

[0068] This embodiment presents a novel method for preparing slices from decayed and softened extra-hard wood, such as... Picture 1 As shown, it includes the following steps:

[0069] S1, Sample Preparation

[0070] The hardwood to be cut (clamwood) Excentrodendron hsienmu Density 1.167 g / cm³ -3 Cut a sample with a length × width × thickness of 2.0 × 1.0 × 1.0 cm (length in the direction of the grain) for later use.

[0071] S2, Vacuum Immersion

[0072] The sample was immersed in a beaker filled with water, and a vacuum was drawn to 9.5 × 10⁻⁶ in a vacuum drying oven. 4 Pa, then depressurize and hold for 25 minutes to allow liquid water to fully penetrate the wood cell cavities.

[0073] S3, Explosives Treatment

[0074] After heating the water-immersed sample to 55°C, a vacuum of 1.5 × 10⁻⁶ was applied. 4 Pa causes liquid water to boil and vaporize rapidly. The resulting water vapor breaks through the pit membrane on the cell wall, opening up channels between cells and improving the permeability of the wood. At the same time, it avoids the possibility of cracking due to the reduction of sample strength caused by high temperature.

[0075] S4, Hot and Cold Water Extraction

[0076] The samples after the blasting treatment were extracted with cold water at 25℃ and hot water at 100℃ for 3.5 hours each time to remove the extracts (tannins, resins, aromatic oils, alkaloids, tannins) contained in the wood and reduce the wood's resistance to decay.

[0077] S5. Adjust moisture content

[0078] The samples were placed in a temperature and humidity control chamber, and the dry and wet bulb temperatures were set to 32℃ and 23℃ respectively. The equilibration treatment lasted for no less than 2 days, and the moisture content was adjusted to 45.5% to facilitate the subsequent decomposition of the decayed wood samples by *Pothomocybe molluscioides*.

[0079] S6, The sample became soft due to bacterial decay.

[0080] Under a slightly acidic environment (pH 6) and with oxygen, at a temperature of 28℃, the *Polyporus flocculationii* was used... Poria vaporaria Allow the sample to decay for 5 days; the axial surface of the sample will decay due to the decomposition of cellulose and hemicellulose by *Potentilla chinensis* until the surface feels soft when gently pressed with a glass rod.

[0081] S7, Frozen Slices

[0082] After soaking the sample in water, it is placed in the freezer until it freezes, allowing the decayed and softened parts of the sample to gain some support strength. Then, it is sliced ​​using a microtome. Because the lignin in the cell walls of the sample is retained, the original shape and size of the cells are preserved. The resulting slices can be made into permanent sections for preservation or used as temporary sections for observation and statistical analysis.

[0083] Comparative Example 1

[0084] This comparative example describes a method for preparing slices from decayed and softened extra-hardwood, using existing technology: The extra-hardwood to be sliced ​​(Hainan Zijing) is... Madhuca hainanensis Density 1.05 g / cm³ -3 Cut a sample with a length × width × thickness of 2.0 × 1.0 × 1.0 cm (length in the direction of the grain) for later use; then use resin to stick the sample onto ordinary glass, polish it with sandpaper, and then use ordinary glass polishing method to cut it into sections.

[0085] Comparative Example 2

[0086] The method for preparing slices from the decay and softening of extra-hard wood in this comparative example is basically the same as that in Example 2, except that the "vacuum immersion + explosion treatment" step is not performed.

[0087] Comparative Example 3

[0088] The method for preparing slices from decayed and softened extra-hard wood in this comparative example is basically the same as that in Example 2, except that the "hot and cold water extraction" step is not performed.

[0089] Comparative Example 4

[0090] The method for preparing slices from the decay and softening of extra-hard wood in this comparative example is basically the same as that in Example 2, except that the step of "adjusting the moisture content to 45%" is not performed.

[0091] Comparative Example 5

[0092] The method for preparing slices from the decay and softening of extra-hard wood in this comparative example is basically the same as that in Example 2, except that the step of "adjusting the moisture content to 45% + decomposition by *Pothomolecus oryzae*" is not performed.

[0093] Experimental Example

[0094] This experimental example is used to verify the feasibility of the method of the present invention and to explore the important impact of each step of the method of the present invention.

[0095] I. Experimental Materials: Hainan Zijing Madhuca hainanensis Density 1.05 g / cm³ -3 .

[0096] II. Experimental methods: The samples were processed and sliced ​​according to the methods of the present invention (taking Example 2 as an example) and Comparative Examples 1 to 5, respectively.

[0097] III. Experimental Results: The results are shown in Table 1.

[0098] Table 1. Experimental results of sample slices from the present invention and comparative examples 1-5

[0099]

[0100] As shown in Table 1:

[0101] (1) By subjecting extra-hard wood to “vacuum immersion and blasting treatment”, the liquid water in the wood can be rapidly boiled and vaporized, opening up the intercellular channels, improving the wood permeability, and facilitating subsequent wood slicing (greatly improving decay and softening properties).

[0102] (2) By "hot and cold water extraction" of the sample after blasting treatment, the extract contained in the wood can be removed, further reducing the wood's resistance to decay and making it easier to slice the wood later (the wood's decay and softening properties are greatly improved).

[0103] (3) By “adjusting the moisture content of the sample + treating with brown rot fungi”, the axial surface of the sample can be decayed and softened, which greatly affects the subsequent wood slicing. The “adjusting the moisture content of the sample” step plays a certain role in enhancing the effect.

[0104] In summary, the method of this invention can successfully slice extra-hardwood, and the slice quality is far superior to that of existing technologies. This provides a strong theoretical foundation and technical means for studying the structure of extra-hardwood, predicting its physical and mechanical properties, and improving its high-value-added processing and utilization.

[0105] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing slices from decayed and softened extra-hard wood, characterized in that, The term "extra-hardwood" refers to wood with a density greater than 1.0 g / cm³. -3 The method for the use of timber includes the following steps: S1, Vacuum Immersion The wood sample was immersed in a container of water, and a vacuum was first applied to 8.5 × 10⁻⁶. 4 ~9.5×10 4 Pa, then depressurize and maintain for 25-35 minutes to allow liquid water to penetrate into the wood cell cavities; S2, Explosives Treatment After heating the water-immersed sample to 45-55℃, a vacuum of 9.5×10⁻⁶ was applied. 3 ~1.5×10 4 Pa causes liquid water to boil and vaporize; S3, Hot and Cold Water Extraction The samples after the blasting treatment were extracted with cold and hot water for 2.5 to 3.5 hours respectively to remove the extracts contained in the wood and reduce the wood's resistance to decay. S4. Adjust moisture content Place the sample in a temperature and humidity control chamber, and set the dry and wet bulb temperatures to 28~32℃ and 19~23℃ respectively, and adjust them to the equilibrium moisture content. S5, The sample became soft and decayed due to bacterial infection. In a weakly acidic environment with oxygen, brown rot fungi were used to cause the sample to decay; the axial surface of the sample decayed due to the decomposition of cellulose and hemicellulose by brown rot fungi. S6, Frozen Slices The sample was soaked in water and then frozen until it was solid, and then sliced.

2. The method for preparing slices by softening and decaying extra-hardwood according to claim 1, characterized in that, In step S1, a vacuum is drawn to 9.0 × 10⁻⁶ in the vacuum drying oven. 4 Pa, then decompress and keep for 30 minutes.

3. The method for preparing slices by softening and decaying extra-hardwood according to claim 1, characterized in that, In step S2, the water-immersed sample is placed in a vacuum drying oven and heated to 50°C, then evacuated to a vacuum level of 1.2 × 10⁻⁶. 4 Pa.

4. The method for preparing slices by softening and decaying extra-hardwood according to claim 1, characterized in that, In step S3, the sample is extracted for 3 hours each with 25°C cold water and 100°C hot water.

5. The method for preparing slices by softening and decaying extra-hardwood according to claim 1, characterized in that, In step S3, the extracts contained in the wood include tannins, resins, aromatic oils, alkaloids, and tannins.

6. The method for preparing slices by softening and decaying extra-hardwood according to claim 1, characterized in that, In step S4, the sample is placed in a temperature and humidity control chamber, and the dry and wet bulb temperatures are set to 30°C and 21°C respectively. The equilibration treatment lasts for no less than 2 days until the final moisture content is 44.5%~45.5%.

7. The method for preparing slices by softening and decaying extra-hardwood according to claim 1, characterized in that, In step S5, the sample is subjected to bacterial decay for 5 days in a weakly acidic environment with a temperature of 28°C and a pH of 6, and under aerobic conditions.

8. The method for preparing slices by softening and decaying extra-hardwood according to claim 1, characterized in that, In step S6, the sample is soaked in water and then placed in the freezer until it freezes, and then sliced ​​using a slicer.

9. The method for preparing slices by softening and decaying extra-hardwood according to claim 1, characterized in that, In step S6, the obtained slices are used to make permanent slices for preservation, or as temporary slices for observation and statistical analysis.

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