Multistage vacuum carbonization process for bamboo wood
By using a multi-stage vacuum carbonization process, the problems of uneven heating inside and outside bamboo and high energy consumption have been solved, achieving uniform color, insect and rot resistance, and performance improvement of bamboo, while reducing equipment costs and energy consumption.
Patent Information
- Application Number
- CN202511707212.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-20
- Publication Date
- 2026-01-02
AI Technical Summary
Traditional bamboo carbonization treatment has problems such as uneven heating inside and outside the bamboo, inconsistent color, high energy consumption, incomplete removal of organic matter inside the bamboo, easy deformation and cracking, and reliance on chemical preservatives.
A multi-stage vacuum carbonization process is adopted, which gradually increases the vacuum level and temperature inside the container through multiple vacuuming and steam circulation processes, and performs multiple carbonization processes, including four carbonization processes, with different vacuum levels and temperatures for each process.
It achieves improved uniformity of color inside and outside bamboo, reduced energy consumption, good insect and rot prevention effects, improved bamboo performance, and low equipment cost and high safety.
Smart Images
Figure SMS_4
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of bamboo processing, in particular to a multi-stage vacuum carbonization process for bamboo. BACKGROUND
[0002] Traditional bamboo carbonization treatment mostly adopts normal pressure or low pressure steam fumigation methods, such as sulfur fumigation, high temperature steam treatment for a long time, etc. These methods have the following problems: uneven heating inside and outside the bamboo, leading to inconsistent color; long carbonization time, high energy consumption; incomplete removal of organic matter such as sugar and starch inside the bamboo, easy to cause insect damage and mold; need to rely on chemical preservatives, environmental and health hazards; limited improvement of mechanical properties of bamboo, easy to deform and crack. SUMMARY
[0003] The technical problem to be solved by the present application is to improve the multi-stage vacuum carbonization process for bamboo, solve the technical problems mentioned in the background, and have the advantages of high efficiency, environmental protection and energy saving.
[0004] In order to solve the above technical problems, the technical scheme adopted by the present application is: The bamboo vacuum carbonization process comprises: The bamboo is placed in a sealed container, and the bamboo is subjected to multiple carbonization treatments in the sealed container, each carbonization treatment comprising the steps of vacuumizing, stopping vacuumizing, and circulating the step of introducing steam; the vacuum degree of the container in each carbonization treatment is in the range of -90KPa to -10KPa, and the pressure value of each carbonization treatment is gradually increased or maintained; in each carbonization treatment, the temperature in the container after the steam is introduced is 100-120℃, and the step of introducing steam is omitted in the last carbonization treatment.
[0005] Further, in the above bamboo vacuum carbonization process, the number of carbonization treatments is three or more.
[0006] Further, in the above bamboo vacuum carbonization process, in the first carbonization treatment, the vacuum degree of the container during vacuumizing is between -85KPa and -75KPa, and the temperature in the container after the steam is introduced is 100-110℃, lasting for 2-5 minutes.
[0007] Further, in the above bamboo vacuum carbonization process, in the second carbonization treatment, the vacuum degree of the container during vacuumizing is between -35KPa and -25KPa, and the temperature in the container after the steam is introduced is 110-115℃, lasting for 2-10 minutes.
[0008] Further, in the above bamboo vacuum carbonization process, in the third carbonization treatment, the vacuum degree of the container during vacuumizing is between -25KPa and -15KPa, and the temperature in the container after the steam is introduced is 110-118℃, lasting for 20-25 minutes.
[0009] Further, in the fourth carbonization treatment of the bamboo vacuum carbonization process, the vacuum degree of the vacuum container is -25KPa to -15KPa, and the duration is 5-10 minutes.
[0010] Further, in the first carbonization treatment of the bamboo vacuum carbonization process, the vacuum degree of the vacuum container is -80KPa, the temperature of the container after steam injection is 100℃, and the duration is 4 minutes.
[0011] Further, in the second carbonization treatment of the bamboo vacuum carbonization process, the vacuum degree of the vacuum container is -30KPa, the temperature of the container after steam injection is 110℃, and the duration is 8 minutes.
[0012] Further, in the third carbonization treatment of the bamboo vacuum carbonization process, the vacuum degree of the vacuum container is -20KPa, the temperature of the container after steam injection is 113℃, and the duration is 20 minutes.
[0013] Further, in the fourth carbonization treatment of the bamboo vacuum carbonization process, the vacuum degree of the vacuum container is -20KPa, and the duration is 8 minutes.
[0014] The beneficial effects of the present application are that the present application adopts a low-temperature and low-pressure multi-stage vacuum carbonization bamboo processing process, which has improved comprehensive performance compared to the high-temperature and high-pressure hot pressing method, and more importantly, the equipment does not need to be manufactured according to the standard of pressure vessels, has lower cost, higher safety, and more energy-saving advantages. DETAILED DESCRIPTION
[0015] To explain the technical content, purposes and effects of the present application in detail, the following embodiments are described.
[0016] Example 1 A vacuum carbonization bamboo processing method, comprising the following steps: A trolley loaded with bamboo strips is sent into a sealed container for four times of carbonization treatment. First carbonization treatment: the container is vacuumed to a vacuum degree of -80KPa, vacuuming is stopped, the temperature of the container after steam injection is 100℃, and the duration is 4 minutes. Second carbonization treatment: the container is vacuumed to a vacuum degree of -30KPa, vacuuming is stopped, the temperature of the container after steam injection is 110℃, and the duration is 8 minutes. Third carbonization treatment: the container is vacuumed to a vacuum degree of -20KPa, vacuuming is stopped, the temperature of the container after steam injection is 113℃, and the duration is 20 minutes. Fourth carbonization treatment: the container is vacuumed to a vacuum degree of -20KPa, and the duration is 8 minutes. After the carbonization treatment is completed, the vacuum is eliminated by exhausting, and the container is opened to take the material.
[0017] Example 2 A processing method of vacuum carbonizing bamboo, comprising the following steps: a trolley with bamboo strips stacked thereon is sent into a closed container for four times of carbonization treatment; first carbonization treatment: the container is vacuumized to a vacuum degree of -85 KPa, vacuumization is stopped, the temperature in the container after steam is introduced is 103℃, and the duration is 3 minutes; second carbonization treatment: the container is vacuumized to a vacuum degree of -35 KPa, vacuumization is stopped, the temperature in the container after steam is introduced is 112℃, and the duration is 6 minutes; third carbonization treatment: the container is vacuumized to a vacuum degree of -23 KPa, vacuumization is stopped, the temperature in the container after steam is introduced is 116℃, and the duration is 23 minutes; fourth carbonization treatment: the container is vacuumized to a vacuum degree of -22 KPa, and the duration is 6 minutes; after the carbonization treatment is completed, the vacuum is eliminated by exhausting, and the container is opened to take the material.
[0018] Example 3 A processing method of vacuum carbonizing bamboo, comprising the following steps: a trolley with bamboo strips stacked thereon is sent into a closed container for four times of carbonization treatment; first carbonization treatment: the container is vacuumized to a vacuum degree of -75 KPa, vacuumization is stopped, the temperature in the container after steam is introduced is 108℃, and the duration is 3 minutes; second carbonization treatment: the container is vacuumized to a vacuum degree of -25 KPa, vacuumization is stopped, the temperature in the container after steam is introduced is 114℃, and the duration is 10 minutes; third carbonization treatment: the container is vacuumized to a vacuum degree of -18 KPa, vacuumization is stopped, the temperature in the container after steam is introduced is 118℃, and the duration is 25 minutes; fourth carbonization treatment: the container is vacuumized to a vacuum degree of -18 KPa, and the duration is 10 minutes; after the carbonization treatment is completed, the vacuum is eliminated by exhausting, and the container is opened to take the material.
[0019] Comparative Example 1 A processing method of vacuum carbonizing bamboo, comprising the following steps: a trolley with bamboo strips stacked thereon is sent into a closed container, steam is introduced under normal pressure to make the temperature in the container reach 113℃, and then the container is naturally dried for 4 hours.
[0020] Comparative Example 2 The processing method of vacuum carbonizing bamboo described in Example 1 is different in that the first carbonization treatment and the second carbonization treatment are omitted, the duration of the third carbonization treatment is increased to 32 minutes, and other conditions remain unchanged.
[0021] Comparative Example 3 The treatment method of vacuum carbonized bamboo material described in Example 1, except that the third and fourth carbonization treatments were omitted, the first carbonization treatment time was increased to 13 minutes, the second carbonization treatment time was increased to 19 minutes, and other conditions were unchanged.
[0022] Comparative Example 4 The treatment method of carbonized bamboo material: put the bamboo material into a pressure vessel, introduce steam to raise the temperature to 125-130℃, the pressure reaches 0.3-0.4Mpa, and keep the temperature and pressure for 1.5 hours.
[0023] Experimental method: 1. Color uniformity test: Test method: Use a color difference meter (such as X-Rite Ci64) to measure the color value (L, a, b ) of the center point and surface point of the bamboo strip cross section, and calculate the color difference ΔE between the two.
[0024] Standard: The smaller the ΔE value, the more consistent the color inside and outside. ΔE < 2 is excellent, ΔE = 2-4 is good, and ΔE > 4 is poor.
[0025] 2. Hardness test: Test method: According to "GB / T 1941-2021 Wood Hardness Test Method", Janka ball indentation method is used for determination.
[0026] Standard: Unit HB (N / mm²). The higher the value, the greater the hardness.
[0027] 3. Compressive strength test: Test method: According to "GB / T 15780-1995 Test Method for Physical and Mechanical Properties of Bamboo Material", standard test specimens (20mm 20mm 30mm) are prepared, and the longitudinal compressive strength is measured on a universal testing machine.
[0028] Standard: Unit kg / cm² or MPa.
[0029] 4. Moisture content: Test method: According to "GB / T 1931-2009 Wood Moisture Content Determination Method", the bamboo test specimen is placed in an oven at 103±2℃ and dried to constant weight, and the moisture content is calculated.
[0030] Standard: Percentage (%).
[0031] 5. Insect resistance: Test method: Refer to GB / T 18261-2013, with slight modification. Put the treated bamboo samples and the control samples in a large number of bamboo long-horned beetle insect boxes, and place them in a temperature of 28±2℃ and humidity of 70±5% for 60 days, and observe and count the number of insect holes eroded.
[0032] 6. Sugar residue detection: Test method: DNS (3,5-dinitrosalicylic acid) method. Take bamboo powder sample hot water extraction, and react with DNS reagent. Observe the color development degree by colorimetric method. The darker the color, the higher the reducing sugar content.
[0033] Standard: Qualitative classification of "no residue", "slight residue", "obvious residue".
[0034] The same part of the same batch of bamboo samples was randomly divided into 30 parts, and 6 parts were divided into 5 groups, and the corresponding carbonized bamboo was obtained by using the method of example 1, comparative examples 1-4. The 6 carbonized bamboo of each group was subjected to the above 6 experiments, and the experimental results were shown in table 1: Table 1 From the results in table 1, after the bamboo was carbonized by the carbonization method of example 1, compared with the bamboo carbonized by the carbonization method of other comparative examples, especially comparative example 1, it had better color uniformity, mechanical properties, insect and corrosion prevention effect and lower water content. In comparative example 2, due to the omission of the first two treatments, the color uniformity and sugar removal effect were reduced, and the mechanical property index was also affected; in comparative example 3, due to the omission of the last two treatments, the insect prevention effect was obviously reduced, and the mechanical property index was also affected. Example 1 compared with comparative example 4 used hot pressing method of high temperature and high pressure, the comprehensive performance was improved, more importantly, the equipment did not need to be manufactured according to the standard of pressure vessel, the cost was lower, the safety was higher, and the energy consumption was more advantageous.
[0035] The above is only an embodiment of the present application, and does not limit the patent range of the present application. Any equivalent transformation or direct or indirect application in related technical field based on the content of the present application is also included in the patent protection range of the present application.
Claims
1. A vacuum carbonization process for bamboo, characterized in that, include: Bamboo is placed in a sealed container and subjected to multiple carbonization processes. Each carbonization process involves a cycle of vacuuming, stopping the vacuuming, and introducing steam. The vacuum level of the container during each carbonization process is in the range of -90 kPa to -10 kPa, and the pressure value is gradually increased or maintained during each carbonization process. During each carbonization process, the temperature inside the container after introducing steam is 100-120°C. The steam introduction step is omitted in the final carbonization process.
2. The bamboo vacuum carbonization process according to claim 1, characterized in that, The carbonization process is performed three or more times.
3. The bamboo vacuum carbonization process according to claim 1, characterized in that, During the first carbonization process, the vacuum level of the container is between -85KPa and -75KPa, and the temperature inside the container after steam is introduced is 100-110℃ for 2-5 minutes.
4. The bamboo vacuum carbonization process according to claim 1, characterized in that, During the second carbonization process, the vacuum level of the container is between -35KPa and -25KPa, and the temperature inside the container after steam is introduced is 110-115℃, which lasts for 2-10 minutes.
5. The bamboo vacuum carbonization process according to claim 1, characterized in that, In the third carbonization process, the vacuum level of the container is between -25KPa and -15KPa, and the temperature inside the container after steam is introduced is 110-118℃ for 20-25 minutes.
6. The bamboo vacuum carbonization process according to claim 1, characterized in that, During the fourth carbonization process, the vacuum level of the container is between -25 kPa and -15 kPa, and it lasts for 5-10 minutes.
7. The bamboo vacuum carbonization process according to claim 1, characterized in that, In the first carbonization process, the vacuum level of the container was -80 kPa, and the temperature inside the container after steam was introduced was 100°C for 4 minutes.
8. The bamboo vacuum carbonization process according to claim 1, characterized in that, In the second carbonization process, the vacuum level of the container was -30 kPa, and the temperature inside the container after steam was introduced was 110°C for 8 minutes.
9. The bamboo vacuum carbonization process according to claim 1, characterized in that, In the third carbonization process, the vacuum level of the container was -20 kPa, and the temperature inside the container after steam was introduced was 113°C for 20 minutes.
10. The bamboo vacuum carbonization process according to claim 1, characterized in that, During the fourth carbonization process, the vacuum level of the container was -20 kPa for 8 minutes.