FUNGAL MYCELIUM FIBERBOARD AND ITS PREPARATION METHOD

Abstract

A method of preparing fungal mycelium fiberboards is provided. First, 1-2 year-old fungal mycelium with a water content of 50-70% is cut into 2-3 cm lengths to obtain cut fungal mycelium. The cut fungal mycelium is then high-pressure steamed to soften it, resulting in the steamed fungal mycelium. The steamed fungal mycelium is mechanically defiberized into fibers and adhesive is added to obtain adhesive-applied fungal mycelium fibers. The adhesive-applied fungal mycelium fibers are then dried at 120-160° C., resulting in dried fungal mycelium fibers. The dried fungal mycelium fibers are then spread, leveled, and pre-pressed to obtain fungal mycelium fiberboard blanks, which are hot-pressed to form the final fungal mycelium fiberboard. This method uses low-cost, fast-growing fungal mycelium as a raw material, which replaces wood chips. The preparation process is simple and easy to promote. The resulting fungal mycelium fiberboard exhibits excellent performance in various indicators and is also environmentally friendly.

Claims

1. A method for preparing a fungal mycelium fiberboard, comprising a plurality of steps: cutting: cutting 1-2 year-old fungal mycelium with a moisture content of 50-70% into 2-3 cm lengths, obtaining the cut fungal mycelium; steaming: high-pressure steaming the cut fungal mycelium to soften it, obtaining the steamed fungal mycelium; defibering and adhesive application: mechanically defiberizing the steamed fungal mycelium into fibers in a hot grinder; during the process of spraying fibers from the hot grinder, adding adhesive to obtain adhesive-applied fungal mycelium fibers; drying: drying the adhesive-applied fungal mycelium fibers at 120-160° C., obtaining dried fungal mycelium fibers with a moisture content of 8.0-8.5%; spreading, leveling, and pre-pressing: spreading, leveling, and pre-pressing the dried fungal mycelium fibers to obtain a fungal mycelium fiberboard blank, with the volume weight of the fungal mycelium fiberboard blank controlled at 110-130 kg/m3; hot pressing: hot pressing the fungal mycelium fiberboard blank to obtain the fungal mycelium fiberboard.

2. The preparation method according to claim 1, wherein the fungal mycelium used is Oasis No. 1 fungal mycelium.

3. The preparation method according to claim 1, wherein the steaming step has a steaming temperature of 158-160° C., a steam pressure of 5.0-5.5 bar, and a steaming time of 2-3 minutes.

4. The preparation method according to claim 1, wherein the defibering and adhesive application step uses urea-formaldehyde resin as the adhesive.

5. The preparation method according to claim 1, wherein that the drying step uses a flash-drying machine for drying.

6. The preparation method according to claim 1, wherein the spreading, leveling, and pre-pressing step compresses the dried fungal mycelium fibers at a compression rate of 50-70%.

7. The preparation method according to claim 1, wherein the hot pressing step has a hot pressing temperature of 153-163° C., a hot pressing pressure of 170-180 bar, and a hot pressing time of 18-22 seconds/mm.

8. The preparation method according to claim 1, wherein the cut fungal mycelium is steamed within 2 days.

9. A fungal mycelium fiberboard, wherein the fungal mycelium fiberboard is produced using a preparation method and the preparation method comprises a plurality of steps: cutting: cutting 1-2 year-old fungal mycelium with a moisture content of 50-70% into 2-3 cm lengths, obtaining the cut fungal mycelium; steaming: high-pressure steaming the cut fungal mycelium to soften it, obtaining the steamed fungal mycelium; defibering and adhesive application: mechanically defiberizing the steamed fungal mycelium into fibers in a hot grinder; during the process of spraying fibers from the hot grinder, adding adhesive to obtain adhesive-applied fungal mycelium fibers; drying: drying the adhesive-applied fungal mycelium fibers at 120-160° C., obtaining dried fungal mycelium fibers with a moisture content of 8.0-8.5%; spreading, leveling, and pre-pressing: spreading, leveling, and pre-pressing the dried fungal mycelium fibers to obtain a fungal mycelium fiberboard blank, with the volume weight of the fungal mycelium fiberboard blank controlled at 110-130 kg/m3; hot pressing: hot pressing the fungal mycelium fiberboard blank to obtain the fungal mycelium fiberboard.

10. The fungal mycelium fiberboard according to claim 9, wherein fungal mycelium used is Oasis No. 1 fungal mycelium.

11. The fungal mycelium fiberboard according to claim 9, wherein the steaming step has a steaming temperature of 158-160° C., a steam pressure of 5.0-5.5 bar, and a steaming time of 2-3 minutes.

12. The fungal mycelium fiberboard according to claim 9, wherein the defibering and adhesive application step uses urea-formaldehyde resin as the adhesive.

13. The fungal mycelium fiberboard according to claim 9, wherein that the drying step uses a flash-drying machine for drying.

14. The fungal mycelium fiberboard according to claim 9, wherein the spreading, leveling, and pre-pressing step compresses the dried fungal mycelium fibers at a compression rate of 50-70%.

15. The fungal mycelium fiberboard according to claim 9, wherein the hot pressing step has a hot pressing temperature of 153-163° C., a hot pressing pressure of 170-180 bar, and a hot pressing time of 18-22 seconds/mm.

16. The fungal mycelium fiberboard according to claim 9, wherein the cut fungal mycelium is steamed within 2 days.

17. The fungal mycelium fiberboard according to claim 9, wherein the density of the fungal mycelium fiberboard is 730-860 kg/m3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0022] In order to describe in detail the technical content, structural features, achieved objectives and effects of the instant application, the following detailed descriptions are given in conjunction with the drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the instant application.

Embodiment 1: An 18 mm-Thick Fungal Mycelium Fiberboard and Its Preparation Method

[0023] Cutting: Cut 1.5-year-old Oasis No. 1 fungal mycelium with a water content of 50.2% into lengths of 2-3 cm. [0024] Steaming: Soften the cut fungal mycelium by high-pressure steaming; control the steaming temperature to be 158-160° C., steam pressure to be 5.0-5.5 bar, and the steaming time to be 2-3 min. [0025] Defibering and adhesive application: Use a hot grinder to mechanically separate the fungal mycelium into fibers, and add adhesive during the spraying of fibers to obtain adhesive-applied fungal mycelium fibers. The amount of added adhesive is 10% of the mass of fungal mycelium after steaming, using urea-formaldehyde resin. [0026] Drying: Use a flash-drying machine for air-drying of adhesive-applied fungal mycelium fibers at 120-160° C., and the moisture content of dried fungal mycelium fibers is 8.05%. [0027] Spreading, leveling, and pre-pressing: spreading, leveling, and pre-pressing the dried adhesive-applied fungal mycelium fibers to obtain a fungal mycelium fiberboard blank. The compression rate of the dried fungal mycelium fibers after pre-pressing is 50-70%; the bulk density of the pre-pressed fungal mycelium is controlled at 110 kg/m.sup.3; the leveling roller height for the fungal mycelium fiberboard blank is 50-60% of that for wood fibers, and the height of the pre-pressed board blank is about 70% of that for wood fibers. The roller height of the fiberboard blank after leveling is about 50-60% of the height of the wooden fibers, and the height of the blank after pre-pressing is around 70% of the height of the wooden fibers. [0028] Hot pressing: hot pressing the mycelium fiberboard billet at 153° C., a pressure of 170 bar, and a time of 22 s/mm to obtain the mycelium fiberboard.

[0029] Compared to using wood chips to make paper, the mycelium fiberboard preparation method provided by the present invention uses more flexible mycelium. In the hot grinder, the mycelium is actually defiberized, making the process simpler and increasing the utilization rate of mycelium, with almost no loss of cellulose. At the same time, the mycelium fibers in the fiberboard are coarser than traditional wood fibers, and less adhesive is used, making the resulting fiberboard more tough, heavier, and more environmentally friendly. However, the inventors found that the mycelium was prone to carbonization and cellulose loss during the preparation process, so the heating temperature during steaming, drying, and hot pressing must be strictly controlled to below 165° C., and preferably below 163° C.

[0030] The various properties of the mycelium fiberboard prepared in Embodiment 1 were tested according to GB/T11718-2009. The results are shown in Table 1:

TABLE-US-00001 TABLE 1 Test results of 18 mm thick mycelium fiberboard Standard Measured No. Check item Unit value value 1 Moisture % 3-13.0 6.2 content 2 Modulus of MPa μL: 24.0  24.0 rupture 3 Modulus of MPa μL: 2300  3610 elasticity 4 Internal bond MPa μL: 0.45  1.17 strength 5 Water % μL: 12.0  6.9 absorption thickness swelling rate 6 Surface bond MPa μL: 24.0  1.50 strength 7 Screw holding N — Surface: 1690/ strength Edge: 1380 8 Formaldehyde mg/ ≤8.0 5.0 emission 100 g

Embodiment 2: An 12 mm-Thick Fungal Mycelium Fiberboard and Its Preparation Method

[0031] In contrast to Embodiment 1, this embodiment involves the following steps: [0032] Cutting: Cutting 2-year-old Oasis 1 fungal straw with a water content of 59.5% into lengths of 2-3 cm; [0033] Steaming: High-pressure steaming of the cut fungus to soften it; steaming temperature is maintained at 158-160° C., steam pressure is maintained at 5.0-5.5 bar, and the steaming time is 2-3 min; [0034] Defibering and Adhesive application: Mechanically defibering the steamed fungus into fibers in a hot grinder, and spraying adhesive during the fiber spraying process to obtain adhesive-applied fungal straw fibers; the amount of adhesive added is 14.9% urea-formaldehyde resin based on the mass of the steamed fungus; [0035] Drying: Using a flash-drying machine to dry the adhesive-applied fungal straw fibers at 120-160° C. until the water content of the dried fungal straw fibers is 8.5%; [0036] Spreading, Leveling, and Pre-Pressing: Spreading, leveling, and pre-pressing the dried fungal straw fibers to obtain the fungal mycelium fiberboard; the compression rate of the pre-pressing is 50-70%; and the bulk density of the fungus after pre-pressing is controlled at 130 kg/m.sup.3; [0037] Hot Pressing: Hot pressing the fungal mycelium fiberboard billet; the hot pressing temperature is 158° C., the hot pressing pressure is 180 bar, and the hot pressing time is 18 s/mm, resulting in the fungal mycelium fiberboard as described above.

[0038] Performance of the prepared fungal mycelium fiberboard in Embodiment 2 was tested according to GB/T11718-2009, and the results are presented in Table 2:

TABLE-US-00002 TABLE 2 Test Results of 12 mm-thick Agricultrual Waste Fiberboard Standard Measured No. Check item Unit value value 1 Moisture % 3-13.0 5.7 content 2 Modulus of MPa μL: 24.0  33.4 rupture 3 Modulus of MPa μL: 2300  4010 elasticity 4 Internal bond MPa μL: 0.45  1.28 strength 5 Water % μL: 12.0  7.8 absorption thickness swelling rate 6 Surface bond MPa μL: 24.0  1.33 strength 7 Density g/cm.sup.3 / 0.78 8 Board Density % / −5.1/+5.1 Deviation 9 Formaldehyde mg/ ≤8.0 5.1 emission 100 g

Embodiment 3—An 15 mm-Thick Fungal Mycelium Fiberboard and Its Preparation Method

[0039] In contrast to the previous two Embodiments, the following are the differences in Embodiment 3: [0040] Cutting: 1-year-old Oasis No. 1 fungus with a water content of 54.5% was cut into lengths of 2-3 cm; [0041] Steaming: The cut fungus was steamed under high pressure to soften it. The steaming temperature was 158-160° C., the steam pressure was 5.0-5.5 bar, and the steaming time was 2-3 min; [0042] Defibering and adhesive application: The fungus after steaming was mechanically defiberized in a hot grinder. During the process of spraying out the fibers in the hot grinder, adhesive was added to obtain adhesive-applied fungal fibers. The amount of adhesive added was 13.0% urea-formaldehyde resin by mass of the steamed fungus; [0043] Drying: The adhesive-applied fungal fibers were dried in a flash-drying machine at 120-160° C., and the moisture content of the dried fungal fibers was 8.35%; [0044] Spreading, leveling, and pre-pressing: The dried fungal fibers were laid, leveled, and pre-pressed to obtain fungal mycelium fiberboard blanks. The compression ratio of pre-pressing was 50-70%, and the volume weight of the fungal mycelium fiberboard blanks was controlled at 125 kg/m.sup.3; [0045] Hot pressing: The fungal mycelium fiberboard blanks were hot-pressed at a temperature of 163° C., a pressure of 175 bar, and a hot pressing time of 20 s/mm to obtain the fungal mycelium fiberboard.

Embodiment 4: A 18mm-Thick Fungal Mycelium Fiberboard and Its Preparation Method

[0046] The difference from Embodiment 1 lies in the steaming step, where the cut fungal mycelium is softened by high-pressure steaming. The steaming temperature is controlled at 150° C., the steam pressure at 4.8 bar, and the steaming time at 5 minutes. Due to the lower steaming temperature, the fungal mycelium fibers are not sufficiently softened, resulting in a smaller bulk density. Consequently, even though the subsequent process steps are the same, the resulting fungal mycelium fiberboard has a lower density, and the values of internal bond strength, water absorption thickness swelling rate, and surface bond strength are all lower than those of the fungal mycelium fiberboards obtained in Embodiments 1-3.

Embodiment 5: An 18mm-Thick Fungal Mycelium Fiberboard and Its Preparation Method

[0047] The difference from Embodiment 1 lies in the steaming step, where the cut fungal mycelium is softened by high-pressure steaming. The steaming temperature is controlled at 170° C., the steam pressure at 6 bar, and the steaming time at 3 minutes. Due to the excessively high steaming temperature and steam pressure, the fungal mycelium fibers suffer from carbonization loss, which affects the spraying process. Consequently, even though the subsequent process steps are the same, the resulting fungal mycelium fiberboard has lower values of modulus of rupture, internal bond strength, water absorption thickness swelling rate, and surface bond strength than those of the fungal mycelium fiberboards obtained in Embodiments 1-3.

Embodiment 6: An 18mm-Thick Wood Fiberboard and Its Preparation Method

[0048] In this embodiment, fast-growing Eucalyptus saligna wood chips are used as raw materials. The cooking step is replaced by a hot grinding process, with the temperature controlled at 172-175° C., the cooking pressure at 7.5-8.0 bar, and the cooking time at 4-5 minutes. In the drying step, the moisture content of the wood fibers is controlled at 9.0-9.5%. During the mat forming, the height of the leveling roller for the wood fiberboard mat is 1.6-2 times the height of the fungal mycelium fiberboard mat, and the height of the pre-pressed wood fiberboard mat is 1.4-1.5 times that of the fungal mycelium fiberboard. In the hot pressing process, the hot pressing temperature of the wood fiberboard is 165-175° C., the maximum hot pressing pressure is 185-195 bar, and the hot pressing time is 15-18s/mm. The various test indicators of the wood fiberboard obtained by the above preparation method also meet the GB/T11718-2009 standard.

[0049] However, the inventor found through calculation that 15 tons of 5-year-old wood materials can produce 10 m.sup.3 of fiberboard, and 15 tons of 2-year-old fungal mycelium materials can also produce 10 m.sup.3 of fiberboard. From the perspective of the planting cycle, the output rate of fungal mycelium materials and the conversion rate of fiberboard are 2.5 times that of wood materials. From the perspective of logging utilization, fungal mycelium can be harvested multiple times per planting, with low investment costs in labor and fertilizers. From the perspective of ecological environmental sustainability, the substitution of fungal mycelium for wood materials in fiberboard production can effectively help to conserve forest trees and promote healthy and sustainable development of the ecological environment. Therefore, this technical solution of the invention has advanced technology and excellent economic and social benefits.

[0050] It should be noted that in this document, terms such as “first” and “second” are used solely to distinguish one entity or operation from another, and do not necessarily imply any actual relationship or sequence between these entities or operations. Additionally, the terms “including,” “comprising,” or any variations thereof are intended to encompass non-exclusive inclusion, such that processes, methods, items, or terminal devices comprising a series of elements include not only those elements explicitly listed, but also other elements that are inherently present in such processes, methods, items, or terminal devices. Unless otherwise specified, the use of the terms “greater than,” “less than,” “exceeding,” etc. does not include the specified number, whereas the terms “above,” “below,” “within,” etc. include the specified number.

[0051] Although the invention has been disclosed and illustrated with reference to particular embodiments, the principles involved are susceptible for use in numerous other embodiments that will be apparent to persons skilled in the art. This invention is, therefore, to be limited only as indicated by the scope of the appended claims.