Preparation method and device of bamboo cellulose-based double antibacterial preservative film

Abstract

The invention relates to the technical field of food fresh-keeping films, and discloses a preparation method and device of a bamboo-cellulose-based double-antibacterial fresh-keeping film, and the preparation method comprises the following steps: grinding bamboo crude fibers into powder, sieving, soaking in deionized water according to a ratio, and drying to obtain a bamboo-cellulose-based double-antibacterial fresh-keeping film; the upper layer bamboo parenchyma cells are separated by utilizing the density difference of bamboo fibers and parenchyma cells through a mechanical method. Placing the parenchymal cells obtained by separation into an acidified sodium chlorite solution, repeating the step five times until holocellulose fibers are obtained, and then repeatedly washing with deionized water. According to the preparation method and device of the bamboo cellulose-based double-antibacterial preservative film, the prepared preservative film has certain biocompatibility, the cellulose preservative film containing two antibacterial factors can express different antibacterial modes in the early stage and the later stage, and the antibacterial effect is good. And compared with a cellulose film, the ultraviolet shielding performance, the tensile strength, the hydrophobicity and the like are improved.

Description

Technical Field

[0001] The invention relates to the technical field of food fresh-keeping films, and in particular to a preparation method and device of a bamboo cellulose-based double antibacterial fresh-keeping film. Background Art

[0002] Food preservation film is used to wrap and preserve food. Traditional packaging materials are mostly derived from petroleum-derived polymer materials, which are difficult to degrade and cannot be regenerated, and are prone to irreversible damage to the environment. At the same time, with the advancement of nanotechnology, various biodegradable materials, such as polysaccharides, proteins, and lipids, enable new food packaging to be produced through cheap and sustainable processes. Cellulose, as the most abundant natural polymer material on earth, exists in plants in the form of aggregates, namely nanocellulose fibrils (NCF). Its sources are very wide, including wood, straw, bamboo, etc.

[0003] At the same time, biodegradable cellulose-based cling film is receiving more and more attention. However, polysaccharide-based packaging films also have many disadvantages, such as poor hydrophobicity and low tensile strength, which limit their application scenarios. Cellulose materials themselves do not have antibacterial effects, so they need to work synergistically with other antibacterial materials. In recent years, adding essential oils to bio-based cling films to enhance antibacterial properties has become a common strategy (such as a bagasse-based nano antibacterial cling film and its preparation method with publication number CN108384064A). However, essential oils evaporate quickly and it is difficult to achieve long-term antibacterial effects. Researchers are looking for strategies to encapsulate essential oils to achieve responsive release or slow release of antibacterial components. For example, polydopamine capsules containing essential oils can give the film superior antibacterial properties and good biodegradability (such as an active packaging film with publication number CN116515145A and its preparation method and application).

[0004] However, the cling film currently prepared has poor antibacterial effect during use, and there is room for improvement in UV blocking ability, hydrophobicity, thermal stability and tensile strength. Summary of the invention

[0005] 1. Technical solution

[0006] The present invention provides the following technical solution: a method and device for preparing a bamboo cellulose-based dual antibacterial cling film, comprising the following steps:

[0007] S1. Grind the bamboo crude fiber into powder and then sieve it, soak it in deionized water according to a certain proportion, and mechanically separate the bamboo fiber and the thin-walled cells to obtain the upper bamboo thin-walled cells by utilizing the different densities of the bamboo fiber and the thin-walled cells.

[0008] S2. Place the separated thin-walled cells in an acidified sodium chlorite solution, repeat this step 5 times until full cellulose fibers are obtained, and then repeatedly wash with deionized water.

[0009] S3. Treat with potassium hydroxide solution to further remove hemicellulose, residual starch and pectin from the whole cellulose fibers, then neutralize the solution with hydrochloric acid and wash repeatedly with deionized water. Finally, the cellulose-rich samples are preserved by soaking in deionized water to prevent the regeneration of hydrogen bonds.

[0010] S4. Dilute the sample and homogenize it at high speed, then continue to dilute it to a certain concentration as the treatment solution, and then perform ultrasonic treatment to obtain the NCF solution.

[0011] S5, mixing the essential oil solution with Tween-80, and obtaining a nano-essential oil emulsion after high-speed shear homogenization.

[0012] S6, essential oil emulsion, Tris buffer, TA solution, Fe 3+ The solutions were mixed and stirred vigorously to prepare EO@MPN solution.

[0013] S7. The NCF suspension was poured into a custom mold and then dried in an oven until completely evaporated. The final product was called NCF film. The same method was used to prepare NCF-EO film, NCF-MPN film, NCF-E / M film, and NCF-E / M-Ag film.

[0014] Preferably, in step S1, the ratio of bamboo crude fiber powder to deionized water is 1:5 (w / w).

[0015] Preferably, in step S2, the acidified sodium chlorite solution needs to be heated to 75 degrees Celsius.

[0016] Preferably, in step S3, the temperature of the potassium hydroxide solution is 90 degrees Celsius, the concentration is 3 wt%, and the concentration of the hydrochloric acid neutralization solution is 1 wt%.

[0017] Preferably, in step S4, the concentration of the sample after dilution is 1 wt%, and the rotation speed of the high-speed shear homogenization is 10000 rpm.

[0018] Preferably, in step S5, the volume of Tween-80 is 1 mL, and the rotation speed of the high-speed shear homogenization is 12000 rpm.

[0019] Preferably, in step S6, the volume and concentration of the essential oil emulsion are 50 mL, 2 wt%, the Tris buffer has a pH value of 8.5 and a volume of 30 mL, and the volume and concentration of the TA solution are 1 mL, 0.01 mM·mL -1 , Fe 3+The volume and concentration of the solution are 1 mL, 0.03 mM·mL -1 Fe 3+ .

[0020] Preferably, in step S7, the volume of the NCF suspension is 100 mL and the temperature of the oven is 35 degrees Celsius.

[0021] A preparation device for a bamboo cellulose-based dual antibacterial cling film comprises a bottom plate, first side plates are arranged on the left and right sides of the top of the bottom plate, second side plates are arranged on the front and back sides of the top of the bottom plate, first studs are fixedly installed on the left and right sides of the top of the bottom plate, first nuts are installed on the external threads of the first studs, second studs are fixedly installed on the front and back sides of the top of the bottom plate, second nuts are fixedly installed on the outside of the second studs, the second nut close to the front side is a butterfly nut, through holes are opened at the first side plate and the second side plate at positions corresponding to the first stud and the second stud, respectively, and the first stud and the second stud pass through the through holes.

[0022] Preferably, the surface of the bottom plate is coated with a polytetrafluoroethylene coating.

[0023] (II) Beneficial effects

[0024] Compared with the prior art, the present invention provides a method and device for preparing a bamboo cellulose-based dual antibacterial cling film, which has the following beneficial effects:

[0025] 1. The preparation method and device of the bamboo cellulose-based dual antibacterial cling film. The prepared cling film has certain biocompatibility and is a cellulose cling film containing two antibacterial factors. It can show different antibacterial modes in the early and late stages, and is improved in terms of ultraviolet shielding, tensile strength, hydrophobicity, etc. compared with cellulose films.

[0026] 2. The preparation method and device of the bamboo cellulose-based dual antibacterial cling film are easy to disassemble and demould during use through the provided bottom plate and the connected structure. Compared with the existing equipment, the processes of coating and peeling the film are saved, and the quality of the film is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 : DSC curves of different fresh-keeping films of the present invention;

[0028] Figure 2 : are TGA curves of different fresh-keeping films of the present invention;

[0029] Figure 3 is the tensile strength of different fresh-keeping films of the present invention;

[0030] Figure 4 is the ultraviolet spectra of different fresh-keeping films of the present invention;

[0031] Figure 5 The antibacterial properties of different fresh-keeping films of the present invention;

[0032] Figure 6 This is a schematic diagram of the appearance and structure of the base plate and the connected mechanism of the present invention;

[0033] Figure 7 It is a schematic diagram of the exploded structure of the base plate and the connected mechanism of the present invention.

[0034] In the figure: 1, bottom plate; 2, first side plate; 3, second side plate; 4, first stud; 5, first nut; 6, second stud; 7, second nut. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Embodiment 1:

[0037] The present invention provides a technical solution: a method and device for preparing a bamboo cellulose-based dual antibacterial cling film, comprising the following steps:

[0038] S1, grinding bamboo crude fiber and passing it through a 100-mesh sieve, soaking it in deionized water at a ratio of 1:5 (w / w), and mechanically separating the bamboo fiber and the thin-walled cells to obtain the upper bamboo thin-walled cells by utilizing the different densities of the bamboo fiber and the thin-walled cells;

[0039] S2. To remove lignin, the separated thin-walled cells were placed in an acidified sodium chlorite solution at 75 degrees Celsius for 1 h. This step was repeated 5 times until full cellulose fibers were obtained, and then washed repeatedly with deionized water;

[0040] S3, treated with 3 wt% potassium hydroxide solution at 90 degrees Celsius for 2 h to further remove hemicellulose, residual starch and pectin from the holocellulose fibers. The solution was then neutralized with 1 wt% hydrochloric acid and repeatedly washed with deionized water. Finally, the cellulose-rich samples were preserved in deionized water to prevent hydrogen bond regeneration.

[0041] S4. Dilute the sample to 1 wt%, homogenize at 10000 rpm, and then continue to dilute to a certain concentration as a treatment solution, followed by ultrasonic treatment to obtain an NCF solution.

[0042] S5. Mix the essential oil solution with 1 mL of Tween-80 and homogenize at 12000 rpm to obtain a nano-essential oil emulsion.

[0043] S6, 50 mL of 2 wt% essential oil emulsion, 30 mL of Tris buffer (pH 8.5), 1 mL of 0.01 mM·mL -1 TA solution, 1 mL 0.03 mM mL -1 Fe 3+ The solutions were mixed and stirred vigorously to prepare EO@MPN solution.

[0044] S7. Pour 100 mL of NCF suspension into a custom mold and then dry it in an oven at 35 degrees Celsius for 10-15 hours until it is completely evaporated. The final product is called NCF film. The same method was used to prepare NCF-EO film (addition of EO emulsion), NCF-MPN film (addition of MPN solution), NCF-E / M film (addition of EO@MPN solution), and NCF-E / M-Ag film (addition of EO@MPN solution and AgNPs). The following table shows the different formulations of the film.

[0045] name Film making liquid composition NCF Film 100 mL NCF solution (0.5 wt%) NCF-EO film 100 mL NCF solution (0.5 wt%) + 10 mL EO emulsion (2 wt%) NCF-MPN film <![CDATA[100 mL NCF solution (0.5 wt%) + 16 mL MPN solution (50 mL deionized water + 30 mL Tris buffer + 1 mL 0.01 mM·mL -1 TA solution + 1 mL 0.03 mM·mL -1 Fe 3+ solution)]]> NCF-E / M Film <![CDATA[100 mL NCF solution (0.5 wt%) + 16 mL EO@MPN solution (50 mL 2 wt% EO emulsion + 30 mL Tris buffer + 1 mL 0.01 mM·mL -1 TA solution + 1 mL 0.03 mM·mL -1 Fe 3+ solution)]]> NCF-E / M-Ag film 100 mL NCF solution (0.5 wt%) + 16 mL EO@MPN solution + 0.05 g AgNPs

[0046] Among them, deionized water was used instead of EO emulsion to prepare NCF-MPN membrane as a control, and the rest of the steps were the same as those of NCF-E / M membrane. To control the same amount of EO added, 10 mL EO emulsion was added to the NCF-EO membrane, and 16 mL EO@MPN solution was added to the NCF-E / M membrane. The weight ratio of AgNPs to NCF was 1:10 (w / w).

[0047] According to the above scheme, the pH of the acidified sodium chlorite solution in step S2 is 4.3-4.8.

[0048] According to the above scheme, the high-speed shear homogenization time in step S4 is 12-30 min, the concentration of the treatment liquid is 0.3-0.5wt%, the ultrasonic treatment power is 480-600 W, and the ultrasonic treatment time is 30-50 min.

[0049] According to the above scheme, the essential oil concentration in step S5 is 2-4 wt%, and the high-speed shear homogenization time is 5-10 min.

[0050] Embodiment 2:

[0051] Preparation of NCF:

[0052] S1. Grind the bamboo crude fiber and pass it through a 100-mesh sieve, soak it in deionized water at a ratio of 1:5 (w / w), and mechanically separate the bamboo fiber and the thin-walled cells to obtain the upper bamboo thin-walled cells by utilizing the different densities of the bamboo fiber and the thin-walled cells.

[0053] S2. To remove lignin, the separated thin-walled cells were placed in an acidified sodium chlorite solution at 75 degrees Celsius for 1 h. This step was repeated 5 times until full cellulose fibers were obtained, and then washed repeatedly with deionized water.

[0054] S3, treated with 3 wt% potassium hydroxide solution at 90 degrees Celsius for 2 h to further remove hemicellulose, residual starch and pectin from the holocellulose fibers. The solution was then neutralized with 1 wt% hydrochloric acid and repeatedly washed with deionized water. Finally, the cellulose-rich samples were preserved in deionized water to prevent hydrogen bond regeneration.

[0055] S4. Dilute the sample to 1 wt%, homogenize at 10,000 rpm for 14 min, and then dilute to 0.5 wt% as the treatment solution, followed by ultrasonic treatment to obtain the NCF solution.

[0056] Embodiment three:

[0057] Preparation of EO@MPN:

[0058] S1. Mix the daidai flower essential oil solution with 1 mL of Tween-80, and homogenize at 12000 rpm for 10 min to obtain the nano essential oil emulsion.

[0059] S2. Mix 50 mL of 2 wt% essential oil emulsion, 30 mL of Tris buffer (pH 8.5), 1 mL of 0.01 mM·mL-1 TA solution, and 1 mL of 0.03 mM·mL-1 Fe3+ solution, and stir vigorously for 10 min to prepare EO@MPN solution.

[0060] Embodiment 4:

[0061] Preparation of plastic wrap:

[0062] S1. Pour 100 mL of NCF suspension into a custom mold and then dry it in an oven at 35 degrees Celsius for 10-15 hours until it is completely evaporated to prepare a nanocellulose film without preservatives, numbered 1.

[0063] S2, additionally adding 10 mL of nano-EO emulsion (2 wt%), and the other steps are the same as S1, to prepare a nanocellulose film containing essential oil, numbered 2.

[0064] S3, additionally add 16 mL of MPN solution (50 mL of deionized water + 30 mL of Tris buffer + 1 mL of 0.01 mM·mL-1 TA solution + 1 mL of 0.03 mM·mL-1 Fe3+ solution), and the other steps are the same as S1 to prepare a nanocellulose film containing metal-polyphenol complexes, numbered 3.

[0065] S4, additionally add 16 mL of EO@MPN solution, and the other steps are the same as S1, to prepare a nanocellulose film containing EO@MPN (nano essential oil capsules), numbered 4.

[0066] S5. An additional 16 mL of EO@MPN solution and 0.05 g of AgNPs (silver nanoparticles) were added. The other steps were the same as S1 to prepare a nanocellulose film containing EO@MPN and AgNPs, numbered 5.

[0067] Embodiment five:

[0068] Determination of thermal properties of cling film:

[0069] Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were performed on the cling film No. 1-5. The experimental results are as follows: Figure 1 and Figure 2 shown.

[0070] As can be seen from the figure, the weight change of the film can be divided into three main stages. The first stage occurs at 30-100 degrees Celsius, which is mainly caused by the evaporation of water, including intermolecular hydrogen bond water and chemically adsorbed water. Films No. 3 and No. 5 have the smallest loss in this stage. The second stage starts at about 170 degrees Celsius, with minimal overall loss, mainly caused by the non-cellulose part. The weight loss starting from about 230 degrees Celsius is mainly caused by the thermal decomposition of cellulose. When heated to 600 degrees Celsius, the weight loss of film No. 5 is the smallest, which depends on the excellent thermal stability of AgNPs. The DSC curve shows that the main internal heat peaks of all films are located near 90 degrees Celsius and have a large range, which may be related to water desorption. The curve shape of the control film No. 1 in the range of 160-200 degrees Celsius is completely different from that of other films, which indirectly indicates the modification effect of antibacterial substances. The results show that EO@MPN and AgNPs have improved thermal stability, especially in the high temperature range.

[0071] Embodiment six:

[0072] Determination of tensile properties of cling film:

[0073] The tensile strength and elongation at break of No. 1-5 cling film were measured using a texture analyzer. The experimental results are as follows: Figure 3 shown.

[0074] The tensile strength of film No. 1 is 21.1 Mpa, and the strength of film No. 5 is increased to 28.47 Mpa. The strengthening effect is obvious, indicating that the mechanical properties of the new film are improved.

[0075] Embodiment seven:

[0076] Determination of UV protection ability:

[0077] The UV spectrometer was used to scan the entire wavelength of the No. 1-5 cling film. The experimental results are as follows: Figure 4 shown.

[0078] Ultraviolet rays can threaten a series of nutrients such as proteins and lipids, such as triggering free radical chain reactions. Therefore, the ultraviolet absorption capacity of the film (200-400 nm range) is particularly worthy of attention. The results show that the absorption rate of film No. 5 is high at wavelengths of 200-400 nm (especially in the range of 200-300 nm), and the characteristic peak at a wavelength of 410 nm is attributed to the addition of Ag. This shows that the ultraviolet light shielding ability of the new composite film is improved.

[0079] Embodiment eight:

[0080] Determination of hydrophobic properties:

[0081] The No. 1-5 fresh-keeping films were analyzed using a water contact angle analyzer, and the experimental results are shown in the table:

[0082] Water contact angles of different films

[0083] serial number angle 1 28.5 ± 2.2 2 43.2 ± 2.3 3 33.3 ± 1.2 4 41.1 ± 1.6 5 39.5 ±2.0

[0084] The water contact angle of film No. 1 is 28.5°, indicating that its hydrophobicity is at a normal level among similar cellulose fresh-keeping films. Due to the addition of nano-essential oil emulsion, the water contact angle of film No. 2 is increased to 43.2°. The water contact angle of film No. 5 is 39.5°, which is 38.6° higher than that of film No. 1, indicating that the hydrophobicity of the new composite film has been significantly improved.

[0085] Embodiment nine:

[0086] Determination of antibacterial properties:

[0087] After adding No. 1-5 cling film to bacterial culture solution, the absorbance at 600 nm was measured to evaluate the antibacterial ability. The experimental results are as follows Figure 5 shown.

[0088] Foodborne pathogens can seriously affect food quality, leading to disease outbreaks and serious health problems. Therefore, antimicrobial activity is very important for food packaging films. All films except film No. 1 showed antimicrobial effects to a certain extent. The absorbance of film No. 3 increased slowly in the initial stage, indicating that the growth of E. coli was inhibited to a certain extent. The growth rate of films No. 4 and No. 5 was slow in the later stage, which may be caused by the dissociation of MPN and the release of internal essential oils due to the growth of bacteria, which made the culture medium tend to be acidic. Acidification did not significantly change the bacterial inhibition ability of film No. 1, but the curves of films No. 4 and No. 5 changed. The inhibitory ability of different films against Staphylococcus aureus was somewhat different from that of E. coli. This may be because the inhibitory effect of essential oil on Staphylococcus aureus was greater than that on E. coli, while the inhibitory effect of AgNP on Staphylococcus aureus was less than that on E. coli. The acidified film was confirmed to have the effect of accelerating the release of antimicrobial components. The above results prove that the new composite film has pH-responsive antibacterial ability and long-lasting antibacterial ability.

[0089] Embodiment ten:

[0090] See also Figure 6 and Figure 7 A preparation device of a bamboo cellulose-based double antibacterial cling film comprises a bottom plate 1, a first side plate 2 is arranged on the left and right sides of the top of the bottom plate 1, a second side plate 3 is arranged on the front and back sides of the top of the bottom plate 1, a first stud 4 is fixedly installed on the left and right sides of the top of the bottom plate 1, a first nut 5 is installed on the external thread of the first stud 4, a second stud 6 is fixedly installed on the front and back sides of the top of the bottom plate 1, a second nut 7 is fixedly installed on the outside of the second stud 6, and the second nut 7 close to the front side is a butterfly nut, and through holes are opened at the corresponding positions of the first side plate 2 and the second side plate 3 to the first stud 4 and the second stud 6, and the first stud 4 and the second stud 6 pass through the through holes.

[0091] Furthermore, the surface of the bottom plate 1 is coated with a polytetrafluoroethylene coating.

[0092] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a bamboo cellulose-based dual antibacterial cling film, characterized in that: The following steps are involved: S1, grinding bamboo crude fiber into powder and sieving, soaking in deionized water according to proportion, and mechanically separating the bamboo fiber and the thin-walled cells to obtain the upper bamboo thin-walled cells by utilizing the different densities of the bamboo fiber and the thin-walled cells; S2, placing the separated thin-walled cells in an acidified sodium chlorite solution, repeating this step 5 times until full cellulose fibers are obtained, and then repeatedly washing with deionized water; S3, treating with potassium hydroxide solution to further remove hemicellulose, residual starch and pectin from the holocellulose fibers, then neutralizing the solution with hydrochloric acid, and then repeatedly washing with deionized water. Finally, the cellulose-rich samples were soaked in deionized water to prevent hydrogen bond regeneration; S4, diluting the sample to high-speed shear homogenization and then further diluting to a certain concentration as a treatment solution, and then performing ultrasonic treatment to obtain an NCF solution; S5, mixing the essential oil solution with Tween-80, and obtaining a nano essential oil emulsion after high-speed shear homogenization; S6, essential oil emulsion, Tris buffer, TA solution, Fe 3+ After the solutions were mixed, they were vigorously stirred to prepare EO@MPN solution; S7. The NCF suspension was poured into a custom mold and then dried in an oven until completely evaporated. The final product was called NCF film. The same method was used to prepare NCF-EO film, NCF-MPN film, NCF-E / M film, and NCF-E / M-Ag film.

2. The method for preparing a bamboo cellulose-based dual antibacterial cling film according to claim 1, characterized in that: In the step S1, the ratio of bamboo crude fiber powder to deionized water is 1:5 (w / w).

3. The method for preparing a bamboo cellulose-based dual antibacterial cling film according to claim 1, characterized in that: In step S2, the acidified sodium chlorite solution needs to be heated to 75 degrees Celsius.

4. The method for preparing a bamboo cellulose-based dual antibacterial cling film according to claim 1, characterized in that: In step S3, the temperature of the potassium hydroxide solution is 90 degrees Celsius, the concentration is 3 wt%, and the concentration of the hydrochloric acid neutralization solution is 1 wt%.

5. The method for preparing a bamboo cellulose-based dual antibacterial cling film according to claim 1, characterized in that: In step S4, the concentration of the sample after dilution is 1 wt%, and the rotation speed of the high-speed shear homogenization is 10000 rpm.

6. The method for preparing a bamboo cellulose-based dual antibacterial cling film according to claim 1, characterized in that: In step S5, the volume of Tween-80 is 1 mL, and the rotation speed of high-speed shear homogenization is 12000 rpm.

7. The method for preparing a bamboo cellulose-based dual antibacterial cling film according to claim 1, characterized in that: In step S6, the volume and concentration of the essential oil emulsion are 50 mL, 2 wt%, the Tris buffer has a pH value of 8.5 and a volume of 30 mL, and the volume and concentration of the TA solution are 1 mL, 0.01 mM·mL -1 , Fe 3+ The volume and concentration of the solution are 1 mL, 0.03 mM·mL -1 Fe 3+ .

8. The method for preparing a bamboo cellulose-based dual antibacterial cling film according to claim 1, characterized in that: In step S7, the volume of the NCF suspension is 100 mL, and the temperature of the oven is 35 degrees Celsius.

9. A device for preparing a bamboo cellulose-based dual antibacterial cling film according to any one of claims 1 to 8, comprising a bottom plate (1), characterized in that: The first side panels (2) are arranged on the left and right sides of the top of the bottom plate (1), and the second side panels (3) are arranged on the front and rear sides of the top of the bottom plate (1). The first studs (4) are fixedly installed on the left and right sides of the top of the bottom plate (1), and the first nuts (5) are installed on the external threads of the first studs (4). The second studs (6) are fixedly installed on the front and rear sides of the top of the bottom plate (1), and the second nuts (7) are fixedly installed on the outside of the second studs (6), and the second nuts (7) close to the front side are butterfly nuts. The first side panels (2) and the second side panels (3) are respectively provided with through holes at positions corresponding to the first studs (4) and the second studs (6), and the first studs (4) and the second studs (6) pass through the through holes.

10. The device for preparing a bamboo cellulose-based dual antibacterial cling film according to claim 9, characterized in that: The surface of the bottom plate (1) is coated with a polytetrafluoroethylene coating.

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