Environment-friendly antibacterial shaving board and manufacturing method

Abstract

The present application relates to the technical field of new functional artificial board, and particularly discloses an environment-friendly antibacterial shaving board, which comprises, from top to bottom, an upper surface layer, an upper subsurface layer, a core layer, a lower subsurface layer and a lower surface layer; the upper surface layer, the core layer and the lower surface layer are prepared from pepper stem shavings and a glue adhesive; the upper subsurface layer and the lower subsurface layer are prepared from any one of a loosened bamboo bundle unit, pepper stem shavings and a glue adhesive; the glue adhesive is a starch-based epoxy resin modified glue adhesive; and the pepper stem shavings and the loosened bamboo bundle unit are subjected to an impregnation treatment with a pepper volatile oil solution. The environment-friendly antibacterial shaving board has a static bending strength MOR of more than 20 MPa, an elastic modulus MOE of more than 3200 MPa and a 24h water absorption thickness expansion rate of less than 3%, and has the advantages of high strength, good water resistance, low formaldehyde emission, environmental protection, antibacterial property, mold resistance and the like, and meets the standard use requirements of the shaving board.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new functional artificial board, in particular to an environment-friendly antibacterial shaving board and a manufacturing method. BACKGROUND

[0002] As an economic crop, Zanthoxylum bungeanum Maxim has high economic value and wide application field. It is not only used for cooking and traditional Chinese medicine, but also widely used in cosmetics, health products and other fields, and is known as "the king of seasoning". The economic utilization part of Zanthoxylum bungeanum Maxim is mainly the fruit. A large amount of waste Zanthoxylum bungeanum Maxim branches and leaves are produced during the annual Zanthoxylum bungeanum Maxim picking and pruning process. The main treatment method for the waste Zanthoxylum bungeanum Maxim branches and leaves at present is burning or discarding on site, thereby causing environmental pollution and resource waste.

[0003] A high-strength shaving board preparation process using Zanthoxylum bungeanum Maxim residues is disclosed in Chinese patent with publication number CN 115042289A. Zanthoxylum bungeanum Maxim residues such as Zanthoxylum bungeanum Maxim branches and leaves and eucalyptus shaving are used as basic raw materials, and melamine urea-formaldehyde resin (MUF) adhesive is used to prepare the shaving board. A high-strength shaving board preparation process using Zanthoxylum bungeanum Maxim residues is disclosed in Chinese patent with publication number CN 115570646A. Zanthoxylum bungeanum Maxim residues such as Zanthoxylum bungeanum Maxim branches and leaves and eucalyptus shaving are also used as basic raw materials, and diphenylmethane diisocyanate (MDI) adhesive is used to prepare the shaving board. The above patents use Zanthoxylum bungeanum Maxim branches, leaves and other waste to prepare the shaving board, which realizes high value-added utilization of Zanthoxylum bungeanum Maxim residues. However, the strength and water resistance of the prepared shaving board are low, and it can only be used as ordinary type shaving board and furniture type shaving board in dry state, and cannot be applied to humid environment and used as load-bearing type shaving board. However, in most actual applications, the environment is in a humid state, especially in southern areas where the environment is humid due to heavy rainfall. The strength and water resistance of the shaving board used for furniture type and load-bearing type are required to be higher. The above disclosed shaving boards cannot meet the requirements.

[0004] The Zanthoxylum bungeanum stem contains complex compounds that are prone to react with the ingredients in traditional adhesives, resulting in reduced activity of the adhesives. For example, alkaloids, coumarin compounds, phenolic compounds and alcohol compounds in the Zanthoxylum bungeanum stem react with traditional urea-formaldehyde resins and phenol-formaldehyde resins, affecting the bonding strength. The amine groups in the alkaloids are prone to Michael addition reaction with formaldehyde, the phenolic hydroxyl groups in the coumarin are prone to form hydrogen bonds or further condensation reaction with formaldehyde groups, and the hydroxyl groups in the phenolic compounds can react with formaldehyde to form ether bonds or methylene bridges, reducing the formaldehyde content and thus the performance of the adhesive. Secondly, traditional adhesives such as urea-formaldehyde resin adhesives, phenol-formaldehyde resin adhesives and isocyanate adhesives are not only environmentally unfriendly, but also lack antibacterial properties. Urea-formaldehyde resins and phenol-formaldehyde resins release harmful substances such as formaldehyde during use, posing a threat to the environment and human health, while isocyanate adhesives, although having good bonding effect, are prone to sticking to the board and adhesive roller during use, posing a key technical problem. The use of melamine-modified urea-formaldehyde resin MUF has a complex production process, high cost, and melamine is a toxic substance, which is not environmentally friendly. Traditional processes usually use high-temperature hot pressing, which not only may cause the decomposition of chemical components in the Zanthoxylum bungeanum stem, producing new chemical substances that interfere with the gluing process, but also increases energy consumption and cost. Although 26 compounds isolated from the Zanthoxylum bungeanum stem, including 7 alkaloids, 10 phenylpropanoids, 4 triterpenes, 2 flavones, 1 benzoic acid, 1 sterol and 1 sugar, have potential antibacterial and environmentally friendly advantages, traditional processes do not effectively retain and utilize these complex components. Therefore, it is necessary to develop a new adhesive and combine a new process to prepare a Zanthoxylum bungeanum residue-containing chipboard, which can not only retain the active substances in the Zanthoxylum bungeanum stem and exert its environmentally friendly and antibacterial advantages, but also meet the requirements of strength, water resistance and other requirements in GB / T 4897-2015 "Chipboard" in a humid state and as a load-bearing chipboard. SUMMARY

[0005] In view of the above problems, the present application provides an environmentally friendly and antibacterial chipboard, which has high strength and has the effects of waterproofing, mold-proofing, antibacterial and the like, and the specific technical solutions are as follows:

[0006] An environmentally friendly and antibacterial chipboard comprises, from top to bottom, an upper surface layer, an upper subsurface layer, a core layer, a lower subsurface layer and a lower surface layer, wherein the upper surface layer, the core layer and the lower surface layer are prepared from Zanthoxylum bungeanum stem chips and an adhesive, the upper subsurface layer and the lower subsurface layer are prepared from any one of a disintegrated bamboo bundle unit and the Zanthoxylum bungeanum stem chips and the adhesive, the adhesive is a starch-based epoxy resin modified adhesive, and the Zanthoxylum bungeanum stem chips and the disintegrated bamboo bundle unit are subjected to impregnation treatment with a Zanthoxylum bungeanum volatile oil solution.

[0007] The environment-friendly antibacterial shaving board of the present application uses pepper stem shavings, cooperates with the disintegrated bamboo bundle unit to obtain high-strength shaving board, uses starch-based epoxy resin modified adhesive to prepare the shaving board, and has the advantages of high bonding strength, strong water resistance, less sizing amount, good environmental protection, etc.; the pepper stem shavings and the disintegrated bamboo bundle unit are impregnated with the pepper volatile oil solution to endow the shaving board with the environmental protection and antibacterial functions.

[0008] Preferably, in the above-mentioned environment-friendly antibacterial shaving board, the specifications of the pepper stem shavings are: shaving thickness range 0.3-0.5 mm, shaving width range 1-2 mm, and shaving length range 5-10 mm; and the specifications of the disintegrated bamboo bundle unit are: diameter 1.5-2 mm and length 10 mm.

[0009] Preferably, in the above-mentioned environment-friendly antibacterial shaving board, the upper and lower surface layers are prepared from the disintegrated bamboo bundle unit and the adhesive, the mass ratio of the pepper stem shavings to the disintegrated bamboo bundle unit in the shaving board is 9:1-1:9, and the pepper stem shavings and the disintegrated bamboo bundle unit are evenly divided into the corresponding layers by mass. The upper and lower surfaces use the pepper stem shavings, which are lower in hardness than bamboo and can better ensure the flatness of the surfaces, the secondary surface layer uses the disintegrated bamboo bundle unit, which uses the high strength in the fiber direction to ensure the strength and nail holding force of the whole composite shaving board, and the core layer uses the pepper stem shavings to fully utilize the pepper stem shavings, thereby ensuring the mechanical properties of the shaving board and reducing the overall cost of the shaving board.

[0010] Preferably, in the above-mentioned environment-friendly antibacterial shaving board, the mass ratio of the pepper stem shavings to the disintegrated bamboo bundle unit in the shaving board is 8:2.

[0011] Preferably, in the above-mentioned environment-friendly antibacterial shaving board, the volume concentration of the pepper volatile oil solution is 10-80%.

[0012] Preferably, in the above-mentioned environment-friendly antibacterial shaving board, the volume concentration of the pepper volatile oil solution is 20%.

[0013] Preferably, in the above-mentioned environment-friendly antibacterial shaving board, the preparation method of the starch-based epoxy resin modified adhesive comprises:

[0014] ①mixing the cassava starch suspension and the oxidizing agent, and performing oxidation reaction by heating;

[0015] ②adding polyvinyl alcohol solution and uniformly mixing, adjusting the pH value to 8.8-9.0, heating to 70-90℃ for gelatinization for 30-40 min; after gelatinization, reducing to room temperature, adding the emulsifier solution and emulsifying for 10-20 min; then adding itaconic acid and ammonium sulfate, and stirring and reacting at 60±5℃ for 4 h; after the reaction is completed, reducing to room temperature, and then adding the modifier for mixing to obtain the composite modified cassava starch-based adhesive;

[0016] ③ The modified cassava starch-based adhesive is mixed with epoxy resin at a mass ratio of 1:1.5-3 to obtain a starch-based epoxy resin modified adhesive.

[0017] Preferably, in the above-mentioned environment-friendly antibacterial chipboard, in the step ①, the mass fraction of cassava starch in the cassava starch suspension is 40-50%, the oxidizing agent is sodium hypochlorite, the amount of sodium hypochlorite is 1-2% of the mass of cassava starch, the oxidation reaction temperature is 40-45℃, and the reaction time is 50-60 min; in the step ②, the mass percentage concentration of the polyvinyl alcohol solution is 10%, the emulsifier is sodium dodecyl sulfate (SDS), the amount of the emulsifier is 0.8-1.2% of the mass of the starch, the amount of itaconic acid is 12-16% of the mass of the starch, the amount of ammonium sulfate is 0.1-0.2% of the mass of the starch, the modifier is N-(2-aminoethyl) 3-aminopropyl trimethoxysilane, and the amount of the modifier is 4-6% of the mass of the starch.

[0018] The cassava starch-based adhesive of the present application is modified by adding N-(2-aminoethyl) 3-aminopropyl trimethoxysilane (KH-792) modifier, which has the following advantages compared with the adhesive grafted with silica sol disclosed in the prior art: first, the bonding performance is better, and the effect is better; KH-792 contains two amino functional groups, which can form strong chemical bonds with the hydroxyl groups in the starch molecules and other organic compounds; second, the compatibility is relatively better; the amino functional groups in KH-792 can promote the compatibility between cellulose and starch, and improve the uniformity of the overall system; third, the water resistance is better; the siloxane network formed by KH-792 and the chemical bonds formed with the hydroxyl groups in the starch can improve the water resistance of the adhesive.

[0019] The present application also provides a preparation method of the above-mentioned environment-friendly antibacterial chipboard, which comprises the following steps:

[0020] (1) Chip screening: screen the Zanthoxylum bungeanum stem chips, and screen out chips with a thickness range of 0.3-0.5 mm, a width range of 1-2 mm, and a length range of 5-10 mm, and dry the chips to a water content of 8%±0.5%;

[0021] (2) Immersion treatment: treat the Zanthoxylum bungeanum stem chips and the defibrated bamboo bundle unit with Zanthoxylum bungeanum volatile oil solution by microwave immersion drying method, and control the water content of the two materials after immersion drying treatment within 8%±0.5%;

[0022] (3) Weighing: weigh the Zanthoxylum bungeanum stem chips and the defibrated bamboo bundle unit according to the mass ratio;

[0023] (4) gluing: the adhesive is evenly sprayed in the zanthoxylum bungeanum stem shaving and the separated bamboo bundle unit respectively, to obtain the zanthoxylum bungeanum stem shaving and the separated bamboo bundle unit after gluing;

[0024] (5) batching: the zanthoxylum bungeanum stem shaving after gluing is divided into three parts according to the quality, the separated bamboo bundle unit after gluing is divided into two parts according to the quality, and the board blank is obtained according to the structure of shaving board;

[0025] (6) hot pressing: the board blank is hot pressed, the hot pressing temperature is 80-90 DEG C, the total hot pressing time is 25-35 min, the hot pressing pressure is 5.0-6.0 MPa, and the target density is 850 ± 5 kg / m 3 , to obtain the environment-friendly antibacterial shaving board.

[0026] Preferably, in the preparation method of the environment-friendly antibacterial shaving board, the microwave impregnation drying treatment time in the step (2) is 20-30 h.

[0027] Preferably, in the preparation method of the environment-friendly antibacterial shaving board, the dosage of the zanthoxylum bungeanum volatile oil solution in the step (2) is 9-11% of the mass of the zanthoxylum bungeanum stem shaving and the separated bamboo bundle unit.

[0028] Preferably, in the preparation method of the environment-friendly antibacterial shaving board, the gluing amount in the step (4) is 65-85 kg / m 3 .

[0029] Preferably, in the preparation method of the environment-friendly antibacterial shaving board, the step (6) further comprises pre-pressing and pressure maintaining, the pre-pressing pressure is 1-1.5 MPa, the time is 3-5 min, the pressure maintaining pressure is 3-4 MPa, and the time is 3-5 min.

[0030] Compared with the prior art, the environment-friendly antibacterial shaving board has the following advantages:

[0031] 1. The environment-friendly antibacterial shaving board has the static bending strength MOR of more than 20 MPa, the elastic modulus MOE of more than 3200 MPa, and the 24h water absorption thickness expansion rate of less than 3%, has the advantages of high strength, good water resistance, low formaldehyde emission, environment-friendly antibacterial, mildew-proof and the like, and the performance index of the shaving board completely meets the requirements of furniture type shaving board used in the humid state according to GB / T4897-2015 "Shaving Board".

[0032] 2. In the environment-friendly antibacterial shaving board of the present application, a new environment-friendly starch-based epoxy resin modified adhesive is used as the adhesive, which has obvious improvement in bonding performance, water resistance and other aspects compared with existing starch-based adhesives; combined with the volatile oil of Zanthoxylum bungeanum and Zanthoxylum bungeanum stems, and the optimized preparation process, a composite shaving board is prepared, which retains volatile oil, amide and various alkaloid components, so that the shaving board has multiple functions such as insect resistance, mold resistance and antibacterial property, not only effectively solves the problem of easy mold of starch and bamboo, but also overcomes the inherent defects of traditional adhesives such as poor water resistance and poor mechanical properties, so that the overall performance can meet the standard requirements; and in the existing disclosure, the Zanthoxylum bungeanum residues need to be combined with wood to prepare artificial boards to meet the standard requirements, but in the present application, pure Zanthoxylum bungeanum stems can also be used to prepare shaving boards, and the performance can also meet the requirements of relevant standards.

[0033] 3. The environment-friendly antibacterial shaving board of the present application has certain special medicinal value, the active ingredients in the board will gradually volatilize over time, which endows it with certain environmental protection and antibacterial functions. The shaving board retains amide and various alkaloid active ingredients in the Zanthoxylum bungeanum stems, and the volatile oil of Zanthoxylum bungeanum exhibits stronger antioxidant capacity than vitamin C, the mechanism is that it can reduce the calcium ion concentration in cells, thereby playing an important role in dilating blood vessels and protecting the cardiovascular system; test results show that the board has met the requirements of 2-level odor standard, has certain convalescent function, and the specific effect needs further research. This feature further enriches the original function of artificial board. This not only broadens the application scene of the shaving board, but also creates a new track and new way for the use of the board. This provides strong support for the reuse of agricultural and forestry waste, significantly extends the industrial chain of Zanthoxylum bungeanum industry, and has wide market prospect and practical value.

[0034] 4. In the preparation method of the environment-friendly antibacterial shaving board of the present application, the hot pressing temperature range is accurately controlled between 80-90℃, which not only can effectively ensure that the cassava starch adhesive reaches the ideal gelatinization state, thereby fully exerting its adhesive properties, but also can avoid the paste or carbonization phenomenon of bamboo due to too high temperature, resulting in the decrease of the performance of bamboo. The preparation process of the present application is helpful to optimize the final performance of the shaving board. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0036] Figure 1 It is a schematic diagram of the shaving board of the present application.

[0037] Figure 2 The physical photos of the shaving board prepared by different volatile oil concentration impregnation of the inventive example 1 and examples 2-1~2-5 are as follows:

[0038] (a) example 2-1; (b) example 1; (c) example 2-2; (d) example 2-3; (e) example 2-4;

[0039] (f) example 2-5;

[0040] Figure 3 (a) the infrared spectrum of the starch-based epoxy resin modified adhesive of example 1; (b) the fluorescence intensity and IB (internal bonding strength) detected under different concentrations of pepper volatile oil solution;

[0041] Figure 4 The gas chromatography-mass spectrum of the shaving board in the inventive example 1 is as follows:

[0042] Figure 5 The comparison chart of the physical and mechanical properties of the shaving board of the inventive example is as follows: (a) the internal bonding strength of example 1 and examples 1-1~1-5; (b) the 24h water absorption thickness expansion rate of example 1 and examples 1-1~1-5; (c) the elastic modulus of example 1 and examples 1-1~1-5; (d) the internal bonding strength of example 2 and examples 2-1~2-5; (e) the 24h water absorption thickness expansion rate of example 2 and examples 2-1~2-5; (f) the elastic modulus of example 2 and examples 2-1~2-5.

[0043] Explanation of main reference signs:

[0044] S1-1: upper surface layer, S2-1: upper sub-surface layer, S3: core layer, S2-2: lower sub-surface layer, S1-2: lower surface layer. DETAILED DESCRIPTION

[0045] The specific embodiments of the present application are described in detail below, but it should be understood that the scope of protection of the present application is not limited by the specific embodiments. Unless otherwise defined, all professional terms used in the following have the same meaning as understood by those skilled in the art. The professional terms used in this paper are only for the purpose of describing the specific embodiments and are not intended to limit the scope of protection of the present application. Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or can be prepared by existing methods.

[0046] Raw material sources: cassava starch: food grade, Harbin Beida Gangxing Co., Ltd.; polyvinyl alcohol (PVA), model BP-24, Guangzhou Qihua Chemical Co., Ltd.; NaClO, mass fraction of active chlorine 20%, analytical pure, Fuchen Chemical Reagent Co., Ltd.; epoxy resin adhesive, industrial grade, Guangzhou Tianlan Chemical Technology Co., Ltd.; emulsifier, sodium dodecyl sulfate (SDS); grafting agent (itaconic acid), Chengdu Huaxia Chemical Reagent Co., Ltd.; initiator (ammonium sulfate), Jinan Zhiheng Chihua Chemical Technology Co., Ltd.; pepper volatile oil, Guangzhou Hai Niyuan Pharmaceutical Co., Ltd.; pepper stem shaving preparation: pepper stem shaving (Pepper Residue) was provided by Guizhou Provincial Institute of Forestry Science, and was re-dried to a moisture content of 8%; bamboo shaving unit preparation: bamboo shaving unit (Bamboo Shavings) was provided by Fujian Yongan Forestry Company, and was re-dried to a moisture content of 8%.

[0047] Polyvinyl alcohol (PVA) solution preparation: polyvinyl alcohol was added to hot water at 90°C and stirred to dissolve to obtain a 10% mass percentage concentration polyvinyl alcohol solution.

[0048] Example 1

[0049] A starch-based epoxy resin modified adhesive preparation includes:

[0050] ① 450 g of cassava starch was added to 550 g of deionized water to prepare a cassava starch suspension, and a 100 g mass percentage concentration of 8% sodium hypochlorite solution was prepared, and the cassava starch and oxidizing agent were added in batches according to 1 / 2, 1 / 5, 1 / 5, 1 / 10 of the total mass into a four-necked flask, i.e. 500 g, 200 g, 200 g, 100 g of cassava starch, and 50 g, 20 g, 20 g, 10 g of sodium hypochlorite, and the temperature was raised to 40°C for 60 minutes of oxidation reaction;

[0051] ② 10 ml of 10% mass percentage concentration polyvinyl alcohol (PVA) solution was added, mixed evenly, and the pH value was adjusted to 8.8, and the temperature was raised to 90°C for 40 minutes of gelatinization; after gelatinization, the temperature was lowered to room temperature (25°C), 10 ml of 1% sodium dodecyl sulfate (SDS) emulsifier solution was added and emulsified for 15 minutes; then 67.5 g of itaconic acid grafting agent and 0.45 g of ammonium sulfate initiator were added, and the mixture was stirred at 60±5°C for 4 hours, and a magnetic stirrer was used to maintain stirring. After the reaction was completed, the temperature was lowered to room temperature (25°C), 22.5 g of amino silane coupling agent (N-(2-aminoethyl) 3-aminopropyl trimethoxysilane (KH-792) modifier was added, mixed evenly, and then discharged to preliminarily obtain a composite modified cassava starch-based adhesive;

[0052] ③The modified cassava starch-based adhesive is mixed with epoxy resin at a mass ratio of 1:2 to prepare a new environment-friendly adhesive, i.e., the starch-based epoxy resin modified adhesive.

[0053] An environment-friendly antibacterial chipboard is prepared as shown in the figure. Figure 1 The upper surface layer S1-1, the upper sub-surface layer S2-1, the core layer S3, the lower sub-surface layer S2-2 and the lower surface layer S1-2 are prepared from pepper stem chips and adhesive, the upper sub-surface layer S2-1 and the lower sub-surface layer S2-2 are prepared from the loosened bamboo bundle unit and adhesive, the adhesive is the starch-based epoxy resin modified adhesive, and the pepper stem chips and the loosened bamboo bundle unit are subjected to the pepper volatile oil solution immersion treatment.

[0054] The preparation method of the environment-friendly antibacterial chipboard of the embodiment includes the following steps:

[0055] (1) Chip screening: the pepper stem chips are screened by a chip screening device for standby use, the screening aperture size is 1×2 mm, and chips with a thickness range of 0.3-0.5 mm, a width range of 1-2 mm and a length range of 5-10 mm are obtained;

[0056] (2) Immersion: the pepper stem chips and the loosened bamboo bundle unit (with a diameter of 1.5-2 mm and a length of 10 mm) are treated by a microwave immersion drying method, the pepper volatile oil extract produced by Guangzhou Hainiyuan Pharmaceutical Co., Ltd. is used as the immersion raw solution, it is assumed that the concentration of the pepper volatile oil raw solution is 100%, water is added, the pepper volatile oil solution with a volume concentration of 20% is prepared, a spray bottle is used to uniformly spray the pepper volatile oil solution onto the pepper stem chips and the loosened bamboo bundle unit, the amount of the pepper volatile oil solution is 10% of the mass of the pepper stem chips and the loosened bamboo bundle unit, the immersion is carried out at room temperature for 24 h in a closed space, and after the immersion is completed, the pepper stem chips and the loosened bamboo bundle unit are placed in a microwave drying oven and dried, and the water content is controlled to be within the range of 8%;

[0057] (3) Chip weighing: 2.24 kg of the pepper stem chips and 0.56 kg of the loosened bamboo bundle unit are weighed, and the mass ratio of the two is 8:2;

[0058] (4) Gluing: the starch-based epoxy resin modified adhesive (with a viscosity of 90 mPa·s) is used, the pepper stem chips and the loosened bamboo bundle unit are poured into a drum mixer (the operating speed is about 40 r / min), and the adhesive is uniformly sprayed onto the pepper stem chips and the loosened bamboo bundle unit by using a high-pressure spray gun, and the amount of the adhesive is 80 kg / m 3 ;

[0059] (5) Grouping: the glued pepper stem chips are evenly divided into three parts, the glued loosened bamboo bundle unit is evenly divided into two parts, and the grouping is carried out according to the following sequence: the upper surface layer S1-1, the upper sub-surface layer S2-1, the core layer S3, the lower sub-surface layer S2-2 and the lower surface layer S1-2. Figure 1The group batch method is used for group batching, and the paving slab size is 550*550mm;

[0060] (6) Hot pressing: three stages in total, the first stage (normal temperature pre-pressing), the pressure is 1.5 MPa, the time is 5 min, the second stage (hot pressing), the hot pressing temperature is 90℃, the hot pressing time is 20 min, the hot pressing pressure is 6.0 MPa, the third stage (pressure maintaining), the pressure is 4 MPa, the time is 5 min, the thickness is 12 mm, and the environment-friendly antibacterial shaving board is obtained.

[0061] (7) Edge cutting: the blank plate after hot pressing is cut to a size of 500*500mm, and then the test sample is sampled according to the sampling in the test standard.

[0062] Example 1-1

[0063] The difference between this embodiment and Example 1 is that the shaving board is a full pepper stem shaving board, and in the preparation method of the shaving board, in step (4), the mass of the pepper stem shaving is 2.8 kg, the mass of the defibrated bamboo bundle unit is 0 kg, the ratio of the pepper stem shaving to the defibrated bamboo bundle unit is 10:0, and the other steps and parameters are the same as those in Example 1.

[0064] Example 1-2

[0065] The difference between this embodiment and Example 1 is that in the preparation method of the shaving board, in step (4), the mass of the pepper stem shaving is 1.68 kg, the mass of the defibrated bamboo bundle unit is 1.12 kg, the ratio of the pepper stem shaving to the defibrated bamboo bundle unit is 6:4, and the other steps and parameters are the same as those in Example 1.

[0066] Example 1-3

[0067] The difference between this embodiment and Example 1 is that in the preparation method of the shaving board, in step (4), the mass of the pepper stem shaving is 1.40 kg, the mass of the defibrated bamboo bundle unit is 1.40 kg, the ratio of the pepper stem shaving to the defibrated bamboo bundle unit is 5:5, and the other steps and parameters are the same as those in Example 1.

[0068] Example 1-4

[0069] The difference between this embodiment and Example 1 is that in the preparation method of the shaving board, in step (4), the mass of the pepper stem shaving is 1.12 kg, the mass of the defibrated bamboo bundle unit is 1.68 kg, the ratio of the pepper stem shaving to the defibrated bamboo bundle unit is 4:6, and the other steps and parameters are the same as those in Example 1.

[0070] Example 1-5

[0071] The difference between this embodiment and embodiment 1 is that in the preparation method of the shaving board, in step (4), the mass of the Zanthoxylum bungeanum stem shavings is 0.56 kg, the mass of the defibrated bamboo bundle unit is 2.24 kg, and the ratio of the Zanthoxylum bungeanum stem shavings to the defibrated bamboo bundle unit is 2:8, and the other steps and parameters are the same as those in embodiment 1.

[0072] Embodiment 2-1

[0073] The difference between this embodiment and embodiment 1 is that in the preparation method of the shaving board, in step (3), the concentration of the Zanthoxylum bungeanum volatile oil solution is 10%, and the other steps and parameters are the same as those in embodiment 1.

[0074] Embodiment 2-2

[0075] The difference between this embodiment and embodiment 1 is that in the preparation method of the shaving board, in step (3), the concentration of the Zanthoxylum bungeanum volatile oil solution is 40%, and the other steps and parameters are the same as those in embodiment 1.

[0076] Embodiment 2-3

[0077] The difference between this embodiment and embodiment 1 is that in the preparation method of the shaving board, in step (3), the concentration of the Zanthoxylum bungeanum volatile oil solution is 50%, and the other steps and parameters are the same as those in embodiment 1.

[0078] Embodiment 2-4

[0079] The difference between this embodiment and embodiment 1 is that in the preparation method of the shaving board, in step (3), the concentration of the Zanthoxylum bungeanum volatile oil solution is 60%, and the other steps and parameters are the same as those in embodiment 1.

[0080] Embodiment 2-5

[0081] The difference between this embodiment and embodiment 1 is that in the preparation method of the shaving board, in step (3), the concentration of the Zanthoxylum bungeanum volatile oil solution is 80%, and the other steps and parameters are the same as those in embodiment 1.

[0082] Comparative Example 1

[0083] The difference between this comparative example and embodiment 1 is that in the preparation of the starch-based epoxy resin modified adhesive, step ③ is not included, and no epoxy resin is added, and the other steps and parameters are the same as those in embodiment 1.

[0084] Comparative Example 2

[0085] The difference between this comparative example and embodiment 1 is that in the preparation of the shaving board, the adhesive is replaced by epoxy resin instead of the starch-based epoxy resin modified adhesive, and the other steps and parameters are the same as those in embodiment 1.

[0086] Comparative Example 3

[0087] The difference between the present comparative example and Example 1 is that the itaconic acid modified starch adhesive (itaconic acid content 7.5%, silica sol content 5%) prepared according to the method described in the literature (Li Na, Tang Yali, et al. Preparation and properties of itaconic acid modified starch adhesive. Fine Chemicals, 2022, Vol. 39, No. 6, 1277-1282) replaces the starch-based-epoxy resin modified adhesive, and other steps and parameters are the same as Example 1.

[0088] Physical properties and mechanical properties of flakeboard of experimental example 1

[0089] The properties of the artificial boards prepared in the examples and comparative examples were tested according to the method in GB / T 4897-2015 standard, and the experimental specimen parameters are shown in Table 1, the specimen thickness is 12 mm, and the test results are shown in Tables 2 and 3.

[0090] Table 1 Experimental specimen parameter table

[0091]

[0092] As can be seen from Tables 2 and 3, the 24h water absorption thickness expansion rate of the flakeboard of the present application is less than 3%, which has excellent water resistance; combined with Figure 5 (b) can be seen that with the increase of the content of the loosened bamboo bundle unit, the 24h water absorption thickness expansion rate decreases, and the water resistance of the flakeboard increases; due to the poor wettability of the surface of the bamboo and the hardness of the material, as well as the problem of wood-bamboo bonding, the elastic modulus decreases to a certain extent, and then shows a growth trend, as shown in 5(c); in combination with various properties, the flakeboard of Example 1 has more excellent comprehensive performance than that of other examples. The MOR of the flakeboard of the present application is more than 20MPa, and the MOE is more than 3200MPa, which is significantly higher than the requirement in GB / T 4897-2015 flakeboard, and has excellent mechanical properties and water resistance.

[0093] As can be seen from Table 2, the comprehensive performance of Example 1 is obviously improved compared with Comparative Example 1, which shows that the new environment-friendly starch-based-epoxy resin modified adhesive of the present application has obvious improvement in bonding performance, water resistance and other aspects compared with the existing starch-based adhesive.

[0094] Table 2 Performance data of flakeboard prepared by the present application examples and comparative examples

[0095]

[0096] Table 3 Performance data of flakeboard prepared by the present application examples

[0097]

[0098]

[0099] Total content of piperamides, formaldehyde release and odor grade in the flakeboard of experimental example 2

[0100] The artificial boards prepared from the examples and comparative examples were tested, the total content of piperamides in the flakeboard was detected according to the method in GH / T 1290-2020 standard, and the formaldehyde release was detected according to the test method in LY / T 3236-2020 standard and section 4.59 (perforator method for measuring formaldehyde content) in GB / T 17657 test methods for physical and chemical properties of artificial boards and veneered artificial boards. The specific test steps are as follows:

[0101] Test method for total content of piperamides:

[0102] The prepared flakeboard was cut into 1mm thick triangular flakes from four corners, 100g was weighed, crushed by a universal crusher and then passed through a 20 mesh sieve, and mixed uniformly. 1g (accurate to 0.0001g) of the crushed and mixed sample was placed in a flask, 50mL of methanol was added, and ultrasonic extraction was performed for 0.5h. The sample was cooled to room temperature, transferred to a 100mL volumetric flask, methanol was used for constant volume, 10mL of supernatant was taken and diluted to 50mL, filtered through a 0.22μm filter membrane, and detected. The sample solution was placed in a 1cm cuvette, methanol was used as a reference, and the absorbance at 270nm was measured. The sample solution with absorbance exceeding the instrument measurement range was diluted with methanol and then measured. Formula 1 was used for calculation. The arithmetic mean of two independent measurement results with absolute difference not greater than 5% of the arithmetic mean under repeatability conditions was taken as the determination value, and the calculation result was kept to two decimal places.

[0103]

[0104] X—the content of piperamide substances in the sample, in milligrams per gram (mg / g);

[0105] A—absorbance of the sample solution at 270nm;

[0106] V—constant volume, in milliliters (mL);

[0107] K—dilution multiple of the sample solution;

[0108] m—sample mass, in grams (g);

[0109] E—absorption coefficient, the absorbance of 1mg / mL piperamide solution at 270nm, wherein it is calculated according to 410 of pepper powder.

[0110] Test method for formaldehyde release:

[0111] According to GB / T17657 Section 4.59 (perforator method for measuring formaldehyde content) in the test method for physicochemical properties of artificial board and veneered artificial board, the prepared shaving board is cut into a powder after being sawed into four corners, 10g of the sample is placed in a flask, under heating conditions, toluene is used as an extraction medium, the formaldehyde in the sample is extracted by liquid-solid extraction circulation, the hot toluene solution containing formaldehyde is overflowed into a perforator sleeve through a sand filter plate, and liquid-liquid extraction is performed with water in the sleeve to transfer the formaldehyde to the water. Under certain conditions, the formaldehyde in the extraction solution reacts with acetylacetone to generate diacetyl dihydro lutein, and the maximum absorption intensity is obtained at a wavelength of 412nm, and the intensity index is converted into a concentration index.

[0112] Odor grade test method:

[0113] Equipment: Wide-mouth glass bottle: should meet the requirements of GB / T 11414-2007, with a volume of 2500mL, a closed lid, and the lid is easy to open and close, and has no odor at temperatures of 20℃ and 65℃. The dryer should meet the requirements of GB / T 15723-1995, with a volume of 40L, a closed lid, and the lid is easy to open and close, and has no odor at 20℃.

[0114] Environment: The test room should be well ventilated, the temperature should be controlled at 20℃, and the indoor environment should be quiet and free of interference and odor during testing.

[0115] Test personnel: The evaluators should have no olfactory defects, no habits such as smoking, using heavy-scented cosmetics, and chewing gum that affect the ability to evaluate smell, and have relatively sensitive sensory organs and discrimination ability, and should pass a discrimination test to select personnel with good sensory sensitivity before starting the evaluation.

[0116] Test piece: After removing the edge (20) mm of the shaving board blank, test pieces are prepared at any position, the test piece specifications are (25) mm x (25±0.5) mm x board thickness, 30 test pieces are taken in turn, the total weight of the test pieces is (200) g, and the test pieces are placed in an odor-free environment with a temperature of 20℃ and a relative humidity of 65% for 72h before testing.

[0117] 1) The dryer and its lid used for testing should be cleaned and dried before the test to ensure that the dryer and its lid are clean and odor-free.

[0118] 2) A clean and odor-free support should be placed in the dryer, the test pieces should be placed vertically on the support, there should be gaps between the test pieces, and the lower edge of the test piece should be 200mm vertically away from the mouth of the dryer. Cover the dryer lid and place it in an environment with a temperature of 20℃ for 24h.

[0119] 3) After the placement time is complete, the odor evaluation test is completed within 30 minutes. When evaluating, the odor evaluator should place his nose close to the dryer (at a vertical distance of about 20-30 mm), remove the cover of the dryer by about 40-50 mm, inhale the gas in the dryer, and record the odor grade according to the provisions of Chapter 9 of this document. When testing each time, the cover is removed for no more than 5 s, and the cover should be immediately closed after testing.

[0120] 4) The test interval between each evaluator should be no less than 2 minutes. The gas sample in each tester can be tested by more than 3 and less than 5 odor evaluators. The opening part of the dryer tested by each odor evaluator should be different.

[0121] 5) When the evaluation results of the members of the evaluation team have a difference of two levels or more, the odor evaluation should be re-sampled.

[0122] 6) The result grade evaluated by the majority is taken as the final odor grade of the sample.

[0123] The test results are shown in Tables 4 and 5. As can be seen from the tables, with the increase of the loosening bamboo bundle unit, the total content of zanthoxylum amide detected increases, the main reason is that there are many vessels in the bamboo, which can absorb and store more zanthoxylum volatile oil components. In the process of microwave impregnation and drying, zanthoxylum volatile oil is impregnated into the vessel, achieving the effect of environmental protection and antibiosis. With the increase of impregnation concentration, the total content of zanthoxylum amide increases, but when the impregnation concentration is too high, it will have an adverse effect on the bonding performance of the adhesive, and then affect the overall properties of the composite material.

[0124] Table 4 Total content of zanthoxylum amide and formaldehyde release amount of the particle board of the embodiment of the application

[0125]

[0126] Table 5 Total content of zanthoxylum amide and formaldehyde release amount of the particle board of the embodiment of the application

[0127]

[0128] Experimental Example 3: Adhesive component detection

[0129] The adhesive prepared in the embodiment was subjected to FTIR (Fourier Transform Infrared Spectroscopy) detection.

[0130] Experimental equipment: Fourier Transform Infrared Spectroscopy (JASCO FT-4000) - Japan Spectroscopy Company;

[0131] Experimental Methods: First, the liquid JASCO FT-4000 sample cell was thoroughly cleaned and dried with acetone. Then, in a fume hood, the adhesive was carefully added to the sample cell using a microsyringe, and the sample cell was sealed. After preheating the JASCO FT-4000, a blank scan was performed to record the background spectrum containing only the sample cell. Subsequently, the sample cell containing the adhesive was placed and scanned. The net spectrum was obtained by subtracting the blank spectrum from the sample spectrum using JASCO FT-4000 software. The positions and intensities of the peaks were analyzed and interpreted, and compared with standard spectra to determine the chemical composition of the adhesive. The spectra are shown below. Figure 2 As shown.

[0132] Fourier transform infrared spectroscopy (FTIR) was used to analyze samples of the adhesive. The analysis revealed that the CO groups in glucose were mainly located in the range of 1000-1800 cm⁻¹. -1 Between, combined Figure 3 Let's look at the range: 1011-1732cm -1 Multiple vibration peaks occurred within the range of 2600-3500 cm⁻¹. -1 Several tremors also occurred between 2600-3500cm. -1 The wavenumber range is dominated by CH and OH groups, indicating that the modified cassava starch underwent a cross-linking reaction with the oxidant and modifier.

[0133] Experiment Example 4: Test of Volatile Organic Compound Content in Particleboard

[0134] The particleboard prepared in the examples and comparative examples was tested, and the content of volatile organic compounds in the particleboard in the confined space was detected in accordance with the method in ISO 12219-1-2021.

[0135] Experimental equipment: Gas Chromatography-Mass Spectrometry (GC-MS) - Qingdao Ruipu Analytical Instrument Co., Ltd.

[0136] Experimental Procedure: The entire experiment was conducted indoors, without direct sunlight. A 0.1m section of the prepared particleboard was selected. 3 Placed at 1m 3 In a sealed climate chamber, the climate chamber is connected to Tenax sampling tubes and DNPH sampling tubes to collect air from a sealed room. The sampling time is 5 min, 10 min, and 15 min. Gas chromatography-mass spectrometry (GC-MS) is used to measure the gas in the sealed space with particleboard.

[0137] The test results are shown in Table 6 and Table 7, and the results show that the contents of benzene, toluene, ethylbenzene and xylene in the sample are all zero, a small amount of styrene and acetaldehyde is caused by the modification of the epoxy resin but the contents are extremely low, both of which are lower than the national standard limit, the formaldehyde release amount is 0.032 mg / L, which meets the E0 standard of formaldehyde release of particle board, and the whole meets the environmental protection requirements.

[0138] Table 6 GC-MS test conditions and results

[0139]

[0140]

[0141] Table 7 GC-MS test conditions and results

[0142]

[0143] Experimental Example 5 Antibacterial performance of particle board

[0144] Experimental method:

[0145] The minimum inhibitory concentration method is used to test the antibacterial performance of the particle board to determine the minimum inhibitory concentration (MIC) of the particle board to evaluate its antibacterial ability.

[0146] Materials and equipment: nutrient broth medium, Hangzhou Anxu Biological Technology Co., Ltd.; plate count medium, Qingdao Gaoke High-tech Industrial Park Haibo Biological Technology Co., Ltd.; potassium ion detection kit, Suzhou Ajie Biological Technology Co., Ltd.; extraction solvent (ethanol), bacterial strain (Escherichia coli), 96-well plate, sterile test tube, sterile pipette, sterile physiological saline, 70% alcohol, constant temperature incubator (37°C), bacterial liquid turbidity standard (such as McFarland standard), spectrophotometer, sterile cotton swab, sterile filter paper, ultrasonic extractor.

[0147] Experimental steps:

[0148] ① Extraction of drug ingredients in particle board

[0149] Drying and crushing: take 20g of particle board, dry it to constant weight, and use a grinder to crush the dried environmentally friendly antibacterial particle board into fine powder; solvent extraction: take 10g of particle board powder, put it into a conical flask, add 100ml of extraction solvent ethanol, use an ultrasonic extractor to extract for 30 minutes, after the extraction liquid is cooled, remove the solid impurities through filter paper, concentrate the extraction liquid to 10ml, and obtain the crude extract of the environmentally friendly antibacterial particle board.

[0150] ② Preparation of bacterial suspension

[0151] Bacterial culture and adjustment: A small amount of bacteria was taken from a freshly cultured bacterial colony and adjusted to a McFarland 0.5 standard (about 1.5 x 10^8 CFU / mL) with sterile saline, and the absorbance was measured at a wavelength of 600 nm with a spectrophotometer to ensure that the bacterial concentration met the standard.

[0152] ③Preparation of dilution series

[0153] Dilution of extract: The crude extract of the environmentally friendly antibacterial particle board was dissolved in ethanol to prepare a high-concentration mother liquor at 10 mg / mL. In each column of a 96-well plate, 100 μL of nutrient broth medium was added, 100 μL of high-concentration mother liquor was added to the first column, and 2-fold serial dilution was performed column by column (100 μL of solution was added to 100 μL of broth in the next column and mixed well, and the process was repeated), until a series of extract solutions with different concentrations was obtained.

[0154] ④Inoculation of bacteria

[0155] 100 μL of adjusted bacterial suspension was added to each well to make the final volume 200 μL. Positive controls (containing only bacteria and medium) and negative controls (containing only extract and medium without bacteria) were set up.

[0156] ⑤Incubation Incubation conditions: The 96-well plate was covered with a lid and incubated in a 37°C constant temperature incubator for 16-18 hours.

[0157] ⑥Observation of results

[0158] Observation and recording: After incubation, the bacterial growth in each well was observed and recorded by naked eye or spectrophotometer (absorbance was measured at a wavelength of 600 nm). The minimum inhibitory concentration (MIC) was defined as the lowest sample concentration with no visible growth (observed by naked eye) or significant decrease in absorbance after incubation.

[0159] ⑦Data recording and analysis

[0160] Data recording: The bacterial growth in each well (with / without growth, or absorbance value) was recorded, and the experiment was repeated three times by the above method. According to the graph drawn from the experiment, the minimum inhibitory concentration (MIC) of the extract of the environmentally friendly antibacterial particle board in Example 1 was about 3.2 mg / mL. In addition, Escherichia coli grew slowly under the action of substances such as volatile oil of Zanthoxylum bungeanum, which proved that the particle board had certain antibacterial properties. By comparing the permeability of Escherichia coli cell membrane at different impregnation concentrations, the effect was best when the impregnation concentration was 80%, but the gluing effect decreased. When the concentration was 20%, it could reach half of 80%. In summary, the particle board with an impregnation concentration of 20% was the best.

[0161] In summary, the present application develops a new functional shaving board through unique structural design and research on environment-friendly adhesive, which not only improves the characteristics of traditional starch-based adhesive, but also makes the shaving board have high strength, good water resistance, environmental protection, antibacterial property and mildew resistance.

[0162] The foregoing description of specific exemplary embodiments of the application has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the application to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. It is intended that the scope of the application be limited not with this detailed description, but rather by the claims appended hereto.

Claims

1. An environmentally friendly antibacterial particle board, characterized in that, From top to bottom, it includes upper surface layer, upper subsurface layer, core layer, lower subsurface layer and lower surface layer, the upper surface layer, core layer and lower surface layer are prepared from Zanthoxylum bungeanum stem shavings and adhesive, the upper subsurface layer and lower subsurface layer are prepared from defibrated bamboo unit and adhesive, the mass ratio of Zanthoxylum bungeanum stem shavings to defibrated bamboo unit in the shaving board is 9:1~1:9, and Zanthoxylum bungeanum stem shavings and defibrated bamboo unit are evenly divided into corresponding layers by mass; the adhesive is starch-based epoxy resin modified adhesive, and Zanthoxylum bungeanum stem shavings and defibrated bamboo unit are treated by Zanthoxylum bungeanum volatile oil solution.

2. The eco-friendly antibacterial shaving board according to claim 1, characterized by, The specification of Zanthoxylum bungeanum stem shavings is that the thickness of shavings ranges from 0.3 to 0.5 mm, the width of shavings ranges from 1 to 2 mm, and the length of shavings ranges from 5 to 10 mm.

3. The eco-friendly antibacterial shaving board according to claim 1, characterized by, The mass ratio of Zanthoxylum bungeanum stem shavings to defibrated bamboo unit in the shaving board is 8:

2.

4. The eco-friendly antibacterial shaving board according to claim 1, characterized by, The volume concentration of Zanthoxylum bungeanum volatile oil solution is 10~80%.

5. The environmentally friendly antimicrobial shaving board according to claim 4, wherein, The volume concentration of Zanthoxylum bungeanum volatile oil solution is 20%.

6. The eco-friendly antimicrobial shaving board according to claim 1, wherein The preparation method of the starch-based epoxy resin modified adhesive comprises: ①Mixing cassava starch suspension and oxidizing agent, and performing oxidation reaction by heating; ②Adding polyvinyl alcohol solution and mixing uniformly, adjusting pH value to 8.8~9.0, and performing gelatinization by heating to 70~90℃ for 30~40 min; after gelatinization, reducing to room temperature, adding emulsifier solution and emulsifying for 10~20 min; then adding itaconic acid and ammonium sulfate, and stirring for 4 h at 60±5℃; after reaction, reducing to room temperature, and then adding modifier for mixing to obtain composite modified cassava starch-based adhesive; ③High-speed mixing the composite modified cassava starch-based adhesive with epoxy resin at a mass ratio of 1:1.5~3 to obtain starch-based epoxy resin modified adhesive.

7. A method of producing an environmentally friendly antibacterial particle board according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: (1) Shaving screening: screening Zanthoxylum bungeanum stem shavings, and screening shavings with thickness ranging from 0.3 to 0.5 mm, width ranging from 1 to 2 mm, and length ranging from 5 to 10 mm, and drying to a moisture content of 8%±0.5%; (2) Immersion treatment: treating Zanthoxylum bungeanum stem shavings and defibrated bamboo unit by microwave immersion drying method using Zanthoxylum bungeanum volatile oil solution, and controlling the moisture content of the two materials after immersion drying treatment within 8%±0.5%; (3) Weighing: weighing Zanthoxylum bungeanum stem shavings and defibrated bamboo unit according to the mass ratio; (4) Gluing: uniformly spraying the adhesive in Zanthoxylum bungeanum stem shavings and defibrated bamboo unit to obtain glued Zanthoxylum bungeanum stem shavings and defibrated bamboo unit; (5) Batch forming: evenly dividing the glued Zanthoxylum bungeanum stem shavings into three parts, and evenly dividing the glued defibrated bamboo unit into two parts, and forming a board blank according to the structure of the shaving board; (6) Hot pressing: hot pressing the board blank, hot pressing temperature is 80~90℃, hot pressing time is 15~25 min, and hot pressing pressure is 5.0~6.0 MPa, to obtain an environmentally friendly antibacterial shaving board.

8. The method for preparing environmentally friendly antibacterial particleboard according to claim 7, characterized in that, In step (2), the microwave immersion drying treatment time is 20~30 h; in step (4), the amount of glue is 65~85 kg / m³.

9. The method for preparing environmentally friendly antibacterial particleboard according to claim 7, characterized in that, The step (6) further comprises pre-pressing and pressure maintaining, the pre-pressing pressure is 1-1.5 MPa, the time is 3-5 min, the pressure maintaining pressure is 3-4 MPa, and the time is 3-5 min.

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