Bamboo fiber extraction method

Abstract

The invention provides a bamboo fiber extraction method, which comprises the following steps of: subdivision treatment: subdividing bamboo wood into bamboo chips; softening pretreatment is conducted, specifically, the bamboo chips are softened, and lignin, cellulose and hemicellulose in the bamboo chips are preliminarily separated; rolling and screening treatment, specifically, the bamboo chips subjected to softening pretreatment are put into a rolling machine to be subjected to multi-stage rolling so that the bamboo chips can be crushed, and bamboo fibers and fragments are formed after the bamboo chips are crushed; and the bamboo fibers and scraps are screened to extract the bamboo fibers, so that the problems of high bamboo hardness, irregular shape, difficulty in extraction and low processing efficiency are solved.

Description

Technical Field

[0001] The invention relates to the technical field of biomass material application, and in particular to a bamboo fiber extraction method. Background Art

[0002] Composite plastic materials, light high-strength plastic plates / sheets and other materials are widely used in many industries such as construction, transportation, electronics, and medical treatment due to their light weight, high strength, corrosion resistance, insulation, and sound insulation. Composite plastic materials and light high-strength plastic plates / sheets contain bio-based fibers. The bio-based fibers are mainly hemp fibers, and most of the raw materials for hemp fibers are imported from abroad. Therefore, the production cost of composite plastic materials and light high-strength plastic plates / sheets is high, and the supply of raw materials is not stable enough.

[0003] Bamboo materials include bamboo fibers, which have the advantages of light weight, good fiber length and strength, strong rigidity, etc., and can be widely used in various fiber processing. In addition, bamboo is a widely distributed herb, which grows fast and is green and environmentally friendly. It is an ideal raw material for replacing hemp fiber in the production of composite plastic materials and high-strength plastic boards / sheets.

[0004] However, due to the high hardness and irregular shape of bamboo, the industrial extraction of bamboo fiber is difficult and the processing efficiency is low. Summary of the invention

[0005] The purpose of the present application is to provide a bamboo fiber extraction method to solve the problem that bamboo material extraction is difficult and the processing efficiency is low.

[0006] In order to solve the above technical problems, this application adopts the following technical solutions:

[0007] According to one aspect of the present application, the present application provides a bamboo fiber extraction method, which includes: a splitting process, splitting bamboo materials into bamboo chips; a softening pretreatment, softening the bamboo chips to initially separate the lignin, cellulose and hemicellulose in the bamboo chips; a rolling and screening process, placing the bamboo chips after the softening pretreatment into a roller press to perform multi-stage rolling to crush the bamboo chips, wherein the bamboo chips are crushed to form bamboo fibers and crushed powder, wherein the bamboo fibers include the cellulose and the hemicellulose, and the crushed powder includes the lignin; and screening the bamboo fibers and the crushed powder to separate the bamboo fibers and the crushed powder.

[0008] In some embodiments, in the roller-sieving process, the crushed powder is screened and separated after each stage of roller processing.

[0009] In some embodiments, when the bamboo pieces enter the roller press, material guiding is performed so that a plurality of the bamboo pieces enter the roller press in the same direction.

[0010] In some embodiments, in the roller-sieving process, the roller press uses a roller and a flat plate or two rollers to roll the bamboo chips.

[0011] In some embodiments, after the splitting process, a conditioning process is further included; in the conditioning process, the bamboo pieces are placed in an environment with different humidity levels so that the moisture content of the bamboo pieces is 45% to 85%.

[0012] In some embodiments, during the softening pretreatment, the bamboo chips are placed in a high-temperature and high-pressure tank, high-temperature and high-pressure steam is introduced into the high-temperature and high-pressure tank and the temperature and pressure are maintained, and then the pressure is released after the temperature and pressure are maintained to soften the bamboo chips.

[0013] In some embodiments, during the softening pretreatment, the temperature preservation range of the high temperature and high pressure tank is 120°C to 210°C, the pressure preservation range of the high temperature and high pressure tank is 0.6Mpa to 2.2Mpa, and the pressure preservation time of the high temperature and high pressure tank is 5 to 20 minutes.

[0014] In some embodiments, when the high-temperature and high-pressure tank is heat-insulated and pressure-maintained, the high-temperature and high-pressure tank is pressure-compensated and temperature-compensated.

[0015] In some embodiments, in the softening pretreatment, the bamboo pieces are placed in a heating tank, an alkali solution is added into the heating tank and heated, and the alkali solution is used to soak the bamboo pieces to soften the bamboo pieces.

[0016] In some embodiments, the alkali solution is sodium hydroxide alkali solution, the concentration range of the sodium hydroxide alkali solution is 3% to 10%, and the soaking time is greater than 2 hours.

[0017] It can be seen from the above technical solution that this application has at least the following advantages and positive effects:

[0018] In the present application, after the bamboo material is split into bamboo chips, the bamboo chips are softened and pre-treated, so that the cellulose, hemicellulose and lignin in the bamboo chips are initially separated. The softened bamboo chips are then put into a roller press for roller pressing, so that the bamboo chips form bamboo fibers and crushed powder. The bamboo fibers and crushed powder are screened to extract bamboo fibers, thereby solving the problems of high hardness, irregular shape, difficult extraction and low processing efficiency of bamboo materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic flow chart of steps S100 to S300 of the bamboo fiber extraction method of the present invention.

[0020] Figure 2 It is a schematic flow chart of step S110 of the bamboo fiber extraction method of the present invention.

[0021] Figure 3It is a schematic flow chart of step S201 of the bamboo fiber extraction method of the present invention.

[0022] Figure 4 It is a schematic flow chart of step S202 of the bamboo fiber extraction method of the present invention.

[0023] Figure 5 It is a schematic flow chart of step S301 of the bamboo fiber extraction method of the present invention. DETAILED DESCRIPTION

[0024] Typical implementations that embody the features and advantages of the present application will be described in detail in the following description. It should be understood that the present application can have various changes in different implementations without departing from the scope of the present application, and the descriptions and illustrations therein are essentially used for illustrative purposes rather than for limiting the present application.

[0025] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0026] In the related art, bamboo materials include lignin, cellulose and hemicellulose. Bamboo materials can be decomposed into bamboo fibers and scraps. Bamboo fibers include cellulose and hemicellulose. The scraps include lignin.

[0027] It is understandable that bamboo fiber may also contain a small amount of lignin, and the crushed pieces may also contain fine cellulose and hemicellulose.

[0028] Bamboo fiber is flexible, while the crumbs are relatively brittle and hard.

[0029] Figure 1 It is a schematic flow chart of steps S100 to S300 of the bamboo fiber extraction method of the present invention.

[0030] See also Figure 1The present application provides a bamboo fiber extraction method, which is used to quickly and stably extract bamboo fibers from bamboo materials, thereby improving the integrity and extraction purity of the bamboo fibers and facilitating the subsequent use of the bamboo fibers.

[0031] It can be understood that the extraction purity is the ratio of the volume of cellulose and hemicellulose to the volume of bamboo fiber.

[0032] See also Figure 1 In this embodiment, the bamboo fiber extraction method includes: step S100, splitting processing.

[0033] Step S100, splitting processing, splitting the bamboo into bamboo slices.

[0034] When extracting bamboo fiber from bamboo, it is not easy to process and extract because of its high hardness, irregular shape and large size. Therefore, it is necessary to split the bamboo into bamboo slices to facilitate the extraction of bamboo fiber and improve the processing and extraction efficiency and extraction quality of bamboo fiber. In addition, after the bamboo is processed into bamboo slices, it is also convenient for subsequent heating, the heating is more uniform, the processing quality is guaranteed, the processing time is reduced, and the extraction efficiency is improved.

[0035] In some embodiments, bamboo materials are split and processed into long bamboo pieces or bamboo pieces of the same or similar specifications to produce long bamboo fibers and short bamboo fibers respectively, thereby being able to meet different back-end market demands and increasing the application scope of bamboo fibers.

[0036] Figure 2 It is a schematic flow chart of step S110 of the bamboo fiber extraction method of the present invention.

[0037] See also Figure 1 and Figure 2 In this embodiment, the bamboo fiber extraction method further includes: step S110, adjustment processing. After step S100, the splitting processing, step S110, the adjustment processing is performed.

[0038] Step S110, conditioning treatment, placing the bamboo pieces in an environment with different humidity, so that the moisture content of the bamboo pieces is 45% to 85%.

[0039] The moisture content of the bamboo strips is 45% to 85%, which can effectively ensure the toughness of the bamboo strips and facilitate the extraction of bamboo fibers in the subsequent processing of the bamboo strips, avoiding the problems of bamboo fiber breakage and bamboo fiber being too short caused by cross-section of the bamboo strips, and effectively ensuring the extraction quality of the bamboo fiber.

[0040] See also Figure 1 In this embodiment, the bamboo fiber extraction method further includes step S200, softening pretreatment. Step S200, softening pretreatment is located after step S100, splitting treatment.

[0041] Step S200, softening pretreatment, softening the bamboo chips to initially separate the lignin, cellulose and hemicellulose in the bamboo chips.

[0042] After the bamboo material is split into bamboo chips, the bamboo chips are softened to initially separate the lignin, cellulose and hemicellulose in the bamboo chips, so as to facilitate the subsequent processing and separation of lignin, cellulose and hemicellulose and improve the extraction efficiency of bamboo fiber.

[0043] In some embodiments, step S200, the softening pre-treatment, is located after step S110, the conditioning treatment, so as to soften the bamboo pieces after the conditioning treatment.

[0044] Figure 3 It is a schematic flow chart of step S201 of the bamboo fiber extraction method of the present invention.

[0045] See also Figure 1 and Figure 3 In some embodiments, in step S200, softening pretreatment, it may include step S201, high temperature and high pressure pretreatment to soften the bamboo chips.

[0046] Step S201, high temperature and high pressure pretreatment, after the bamboo pieces are placed in a high temperature and high pressure tank, high temperature and high pressure steam is introduced into the high temperature and high pressure tank to keep the temperature and pressure, and then the pressure is released after keeping the temperature and pressure to soften the bamboo pieces.

[0047] When the bamboo pieces enter the high temperature and high pressure tank, the high temperature and high pressure tank is sealed.

[0048] Afterwards, high-temperature and high-pressure steam is introduced into the high-temperature and high-pressure tank, and the temperature and pressure are kept for a preset time so that the steam can fully penetrate into the bamboo slices. The high-temperature and high-pressure steam penetrates into the fibers and cell wall pores of the bamboo slices, forming hydrogen bonds with the hydroxyl groups in the cellulose. Under the combined action of high temperature and steam, this hydrogen bond causes the cellulose to soften and degrade, low-molecular substances to dissolve, and the connection between the fibers to weaken, thereby facilitating the subsequent extraction of bamboo fibers.

[0049] Finally, the high temperature and high pressure tank is depressurized to facilitate the removal of the softened bamboo chips for subsequent processing to separate the bamboo fibers and fragments.

[0050] In some embodiments, when the pressure is released in the high-temperature and high-pressure tank, the pressure release rate is slower than the pressure release rate during steam explosion, so as to avoid a sudden drop in pressure in the high-temperature and high-pressure tank and avoid a steam explosion reaction, thereby ensuring the integrity of the bamboo fiber and improving the extraction quality of the bamboo fiber.

[0051] In some embodiments, step S201, high temperature and high pressure pretreatment, the insulation range of the high temperature and high pressure tank is 120℃~210℃, the pressure range of the high temperature and high pressure tank is 0.6Mpa~2.2Mpa, and the pressure holding time of the high temperature and high pressure tank is 5~20min, so that the water vapor can fully react with the bamboo pieces, improve the subsequent extraction and processing efficiency of the bamboo fiber, and ensure the extraction quality of the bamboo fiber.

[0052] In some embodiments, when the high temperature and high pressure tank is insulated and pressure maintained, the high temperature and high pressure tank is pressure-compensated and temperature-compensated to maintain the temperature and pressure in the high temperature and high pressure tank. In addition, when the high temperature and high pressure tank is insulated and pressure maintained, the temperature in the high temperature and high pressure tank is prevented from being lower than the insulation range and the pressure is prevented from being lower than the pressure maintenance range, thereby ensuring that the water vapor and the bamboo pieces fully hydrogen bond, facilitating the subsequent separation of bamboo fibers, ensuring the integrity of the bamboo fibers, and improving the extraction quality of the bamboo fibers.

[0053] Figure 4 It is a schematic flow chart of step S202 of the bamboo fiber extraction method of the present invention.

[0054] See also Figure 1 and Figure 4 In some other embodiments, in step S200, softening pretreatment, it may include step S202, alkali solution pretreatment to soften the bamboo chips.

[0055] Step S202, alkali solution pretreatment, after the bamboo pieces are placed in a heating tank, alkali solution is added into the heating tank and heated, and the alkali solution is soaked in the bamboo pieces to soften the bamboo pieces.

[0056] When the bamboo chips enter the heating tank, alkali solution is introduced into the heating tank and the heating tank is heated. The alkali solution fully contacts the bamboo chips and dissolves the lignin and hemicellulose in the bamboo chips when the temperature rises, so that the binding force between cellulose, hemicellulose and lignin is weakened, thereby reducing the mechanical strength of the bamboo chips and softening the bamboo chips.

[0057] In other embodiments, the alkali solution is sodium hydroxide alkali solution, the concentration range of the sodium hydroxide alkali solution is 3% to 10%, and the soaking time is greater than 2 hours, so that the alkali solution can efficiently and fully react with the bamboo pieces when heated, thereby improving the extraction efficiency and quality of the bamboo fiber while ensuring the integrity of the bamboo fiber.

[0058] It should be noted that different alkali solution concentrations, temperatures and soaking times have a significant effect on the softening effect of bamboo strips.

[0059] In other embodiments, the alkali solution may also be sodium carbonate alkali solution, potassium hydroxide alkali solution, etc.

[0060] See also Figure 1In this embodiment, the bamboo fiber extraction method further includes step S300, roller pressing and screening treatment. S300, roller pressing and screening treatment is located after S200, softening pretreatment.

[0061] Step S300, roller pressing and screening treatment, putting the softened pre-treated bamboo chips into a roller press for multi-stage rolling to crush the bamboo chips, and forming bamboo fibers and crushed chips after crushing. The bamboo fibers include cellulose and hemicellulose, and the crushed chips include lignin; the bamboo fibers and crushed chips are screened to separate the bamboo fibers and crushed chips.

[0062] When the bamboo chips are softened, they are put into a roller press, which squeezes the bamboo chips to crush them into bamboo fibers and crushed powder. After that, the bamboo fibers and crushed powder are screened to separate them. The separated bamboo fibers and crushed powder are collected and packaged separately, so that they can be used to produce different products respectively, thereby improving the utilization efficiency of resources.

[0063] Figure 5 It is a schematic flow chart of step S301 of the bamboo fiber extraction method of the present invention.

[0064] See also Figure 1 and Figure 5 In this embodiment, in step S300, roller screening process, step S301, multi-stage screening process can also be included.

[0065] Step S301, multi-stage screening treatment, after each stage of rolling processing, the crushed particles are screened and separated.

[0066] After each stage of rolling processing, the crushed particles are screened and separated, thereby reducing the crushed particles attached to the bamboo fibers, reducing the crushed particles entering the subsequent rolling processing, reducing the ineffective rolling during the subsequent rolling processing, improving the rolling quality, and fully separating the bamboo fibers from the crushed particles, thereby improving the extraction quality of the bamboo fibers.

[0067] See also Figure 1 In this embodiment, in step S300, in the roller pressing and screening process, the roller press uses a roller and a flat plate or two rollers to press the bamboo pieces, so as to fully squeeze the bamboo pieces, avoid the problem of tearing the bamboo fibers when extracting the bamboo fibers by the steam explosion method, and ensure the integrity of the bamboo fibers.

[0068] In some embodiments, when the roller press uses two rollers to roll the bamboo pieces, each level of rolling processing may include multiple rollers. The two rollers are arranged opposite to each other to form a roller group. The multiple rollers respectively form multiple roller groups. The multiple roller groups are arranged at intervals in the up and down directions, so that the bamboo pieces need to be rolled multiple times by multiple roller groups during each level of rolling processing, so that the bamboo pieces are gradually crushed and refined to form bamboo fibers, the rolling quality is improved, the bamboo fibers are fully separated from the fragments, and the extraction quality of the bamboo fibers is improved.

[0069] In other embodiments, when the roller press uses rollers and a flat plate to press the bamboo slices, the rollers rotate to press the bamboo slices against the flat plate, so that the softened bamboo slices are crushed to form bamboo fibers and lignin.

[0070] In other embodiments, a plurality of rollers and at least one flat plate may be used in the roller press. The plurality of rollers may be adapted to the flat plate to press the bamboo pieces onto the flat plate, thereby crushing the bamboo pieces to form bamboo fibers and fragments. The bamboo pieces are crushed multiple times by the plurality of rollers and the flat plate, thereby improving the rolling quality, fully separating the bamboo fibers from the fragments, and improving the extraction quality of the bamboo fibers.

[0071] It is understandable that in each stage of rolling, the bamboo pieces need to be put into a roller press for multiple rolling. The bamboo pieces need to be rolled multiple times in the multi-stage rolling, so that the bamboo pieces are gradually crushed and refined to form bamboo fibers, ensuring the extraction purity and extraction quality of the bamboo fibers.

[0072] See also Figure 1 In this embodiment, when the roller rolls the bamboo pieces, the surface roughness of the roller is increased, so that when the roller contacts the bamboo pieces, the local pressures borne at different places on the bamboo pieces are different, so that the bamboo pieces are broken due to uneven force, thereby improving the efficiency of the roller in breaking the bamboo pieces, thereby improving the processing efficiency of the bamboo pieces.

[0073] See also Figure 1 In this embodiment, when the bamboo pieces enter the roller press, the material is guided so that multiple bamboo pieces enter the roller press in the same direction.

[0074] When the bamboo chips enter the roller press, the material is guided so that the fiber extension direction of the bamboo chips is the same as the length direction of the bamboo chips, and the length direction of the bamboo chips is the same as the roller pressing and crushing direction of the roller press, so that the roller press gradually crushes the bamboo chips along the length direction of the bamboo chips, thereby ensuring that the bamboo fibers can bend and pass when the bamboo chips are crushed, and the lignin is crushed to form crumbs, thereby ensuring the integrity of the bamboo fibers after crushing and improving the extraction quality of the bamboo fibers.

[0075] Furthermore, after the multiple bamboo pieces are all guided and rolled, they can be crushed so that the extension directions of the multiple bamboo fibers produced are the same or similar, thereby facilitating the collection and storage of the multiple bamboo fibers, and arranging the multiple bamboo fibers in the same direction, which is convenient for the subsequent use of the bamboo fibers.

[0076] It can be understood that a plurality of bamboo pieces enter the roller press in the same direction, which is the same direction or a similar direction, so as to facilitate the collection and storage of the produced bamboo fibers.

[0077] See also Figure 1In this embodiment, in step S300, in the roller pressing and screening process, after the bamboo chips are roller pressed and crushed, they are screened by vibration, stirring, material shifting and / or blowing to fully remove the crushed fragments after roller pressing and prevent the fragments from entering the subsequent multi-stage roller pressing process, reduce the ineffective rolling of the roller press, and improve the extraction quality of bamboo fiber.

[0078] See also Figures 1 to 5 The present invention provides a method for extracting bamboo fiber, which comprises first splitting bamboo material into bamboo chips, and then placing the bamboo chips into a processing tank for processing and softening, so that lignin, cellulose and hemicellulose in the bamboo chips are initially separated.

[0079] When the bamboo pieces are softened, they are put into a roller press to crush them, thus forming bamboo fibers and crumbs. Afterwards, the bamboo fibers and crumbs are screened to separate the crumbs and bamboo fibers, thereby effectively ensuring the integrity of the bamboo fibers, improving the extraction quality of the bamboo fibers, and facilitating the subsequent use of paper fibers. In addition, the problems of high hardness, irregular shape, difficult extraction, and low processing efficiency of bamboo materials are effectively solved.

[0080] Although the present application has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present application can be implemented in a variety of forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A method for extracting bamboo fiber, characterized in that: include: Splitting treatment, splitting the bamboo into bamboo pieces; Softening pretreatment, softening the bamboo chips to initially separate the lignin, cellulose and hemicellulose in the bamboo chips; Rolling and screening treatment, putting the bamboo chips after the softening pretreatment into a roller press for multi-stage rolling to crush the bamboo chips, the bamboo chips are crushed to form bamboo fibers and crushed powder, the bamboo fibers include the cellulose and the hemicellulose, and the crushed powder includes the lignin; the bamboo fibers and the crushed powder are screened to separate the bamboo fibers and the crushed powder.

2. The method for extracting bamboo fiber according to claim 1, characterized in that: In the roller-sieving process, the crushed particles are screened and separated after each stage of roller processing.

3. The method for extracting bamboo fiber according to claim 1, characterized in that: When the bamboo pieces enter the roller press, the material is guided so that the plurality of bamboo pieces enter the roller press in the same direction.

4. The method for extracting bamboo fiber according to claim 1, characterized in that: In the roller pressing and screening process, the roller pressing machine presses the bamboo chips in a roller and flat plate or two rollers against each other.

5. The method for extracting bamboo fiber according to claim 1, characterized in that: After the segmentation process, an adjustment process is also included; The conditioning treatment is to place the bamboo pieces in an environment with different humidity so that the moisture content of the bamboo pieces is 45% to 85%.

6. The method for extracting bamboo fiber according to claim 1, characterized in that: In the softening pretreatment, the bamboo pieces are placed in a high-temperature and high-pressure tank, high-temperature and high-pressure steam is introduced into the high-temperature and high-pressure tank and the temperature and pressure are maintained, and then the pressure is released after the temperature and pressure are maintained to soften the bamboo pieces.

7. The method for extracting bamboo fiber according to claim 6, characterized in that: In the softening pretreatment, the temperature keeping range of the high temperature and high pressure tank is 120° C. to 210° C., the pressure keeping range of the high temperature and high pressure tank is 0.6 MPa to 2.2 MPa, and the pressure keeping time of the high temperature and high pressure tank is 5 to 20 minutes.

8. The method for extracting bamboo fiber according to claim 6, characterized in that: When the high-temperature and high-pressure tank is heat-insulated and pressure-maintained, the high-temperature and high-pressure tank is pressure-replenished and temperature-replenished.

9. The method for extracting bamboo fiber according to claim 1, characterized in that: In the softening pretreatment, the bamboo pieces are placed in a heating tank, alkali solution is added into the heating tank and heated, and the alkali solution soaks the bamboo pieces to soften the bamboo pieces.

10. The method for extracting bamboo fiber according to claim 9, characterized in that: The alkali solution is sodium hydroxide alkali solution, the concentration range of the sodium hydroxide alkali solution is 3% to 10%, and the soaking time is greater than 2 hours.

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